TUT: added two unsteady adjoint optimisation tutorials

showcasing the use of compressedFullStorage and binomialCheckPointing

src/OpenFOAM/db/Time/Time.C

@@ -967,6 +967,34 @@ bool Foam::Time::end() const
 }
 
 
+bool Foam::Time::reverseRun() const
+{
+    // Must not solve for the 0 time step
+    bool isRunning = value() > (endTime_ + 0.5*deltaT_);
+
+    return isRunning;
+}
+
+
+bool Foam::Time::reverseLoop()
+{
+    const bool isRunning = reverseRun();
+
+    if (isRunning)
+    {
+        operator--();
+    }
+
+    return isRunning;
+}
+
+
+bool Foam::Time::reverseEnd() const
+{
+    return value() < (endTime_ - 0.5*deltaT_);
+}
+
+
 bool Foam::Time::stopAt(const stopAtControls stopCtrl) const
 {
     if (stopCtrl == stopAtControls::saUnknown)
@@ -1365,4 +1393,242 @@ Foam::Time& Foam::Time::operator++(int)
 }
 
 
+Foam::Time&
+Foam::Time::operator-=(const dimensionedScalar& deltaT)
+{
+    return operator-=(deltaT.value());
+}
+
+
+Foam::Time& Foam::Time::operator-=(const scalar deltaT)
+{
+    setDeltaT(deltaT);
+    return operator--();
+}
+
+
+Foam::Time& Foam::Time::operator--()
+{
+    deltaT0_ = deltaTSave_;
+    deltaTSave_ = deltaT_;
+
+    // Save old time value and name
+    const scalar oldTimeValue = timeToUserTime(value());
+    const word oldTimeName = dimensionedScalar::name();
+
+    // Decrease time
+    setTime(value() - deltaT_, timeIndex_ - 1);
+
+    if (!subCycling_)
+    {
+        // If the time is very close to zero reset to zero
+        if (mag(value()) < 10*SMALL*deltaT_)
+        {
+            setTime(0.0, timeIndex_);
+        }
+
+        if (sigStopAtWriteNow_.active() || sigWriteNow_.active())
+        {
+            // A signal might have been sent on one processor only
+            // Reduce so all decide the same.
+
+            label flag = 0;
+            if (sigStopAtWriteNow_.active() && stopAt_ == saWriteNow)
+            {
+                flag += 1;
+            }
+            if (sigWriteNow_.active() && writeOnce_)
+            {
+                flag += 2;
+            }
+            reduce(flag, maxOp<label>());
+
+            if (flag & 1)
+            {
+                stopAt_ = saWriteNow;
+            }
+            if (flag & 2)
+            {
+                writeOnce_ = true;
+            }
+        }
+
+        writeTime_ = false;
+
+        switch (writeControl_)
+        {
+            case wcNone:
+            case wcUnknown:
+            break;
+
+            case wcTimeStep:
+                // Avoid writing just because timIndex_ is zero
+                writeTime_ = 
+                    !(timeIndex_ % label(writeInterval_)) && timeIndex_;
+            break;
+
+            case wcRunTime:
+            case wcAdjustableRunTime:
+            {
+                const label writeIndex = label
+                (
+                    ((value() - startTime_) - 0.5*deltaT_)
+                  / writeInterval_
+                );
+
+                if (writeIndex < writeTimeIndex_)
+                {
+                    writeTime_ = true;
+                    writeTimeIndex_ = writeIndex;
+                }
+            }
+            break;
+
+            case wcCpuTime:
+            {
+                const label writeIndex = label
+                (
+                    returnReduce(elapsedCpuTime(), maxOp<double>())
+                  / writeInterval_
+                );
+                if (writeIndex > writeTimeIndex_)
+                {
+                    writeTime_ = true;
+                    writeTimeIndex_ = writeIndex;
+                }
+            }
+            break;
+
+            case wcClockTime:
+            {
+                const label writeIndex = label
+                (
+                    returnReduce(elapsedClockTime(), maxOp<double>())
+                  / writeInterval_
+                );
+                if (writeIndex > writeTimeIndex_)
+                {
+                    writeTime_ = true;
+                    writeTimeIndex_ = writeIndex;
+                }
+            }
+            break;
+        }
+
+
+        // Check if endTime needs adjustment to stop at the next
+        // reverseRun()/reverseEnd()
+        if (!reverseEnd())
+        {
+            if (stopAt_ == saNoWriteNow)
+            {
+                endTime_ = value();
+            }
+            else if (stopAt_ == saWriteNow)
+            {
+                endTime_ = value();
+                writeTime_ = true;
+            }
+            else if (stopAt_ == saNextWrite && writeTime_ == true)
+            {
+                endTime_ = value();
+            }
+        }
+
+        // Override writeTime if one-shot writing
+        if (writeOnce_)
+        {
+            writeTime_ = true;
+            writeOnce_ = false;
+        }
+
+        // Adjust the precision of the time directory name if necessary
+        if (writeTime_)
+        {
+            // Tolerance used when testing time equivalence
+            const scalar timeTol =
+                max(min(pow(10.0, -precision_), 0.1*deltaT_), SMALL);
+
+            // User-time equivalent of deltaT
+            const scalar userDeltaT = timeToUserTime(deltaT_);
+
+            // Time value obtained by reading timeName
+            scalar timeNameValue = -VGREAT;
+
+            // Check that new time representation differs from old one
+            // reinterpretation of the word
+            if
+            (
+                readScalar(dimensionedScalar::name(), timeNameValue)
+             && (mag(-timeNameValue + oldTimeValue - userDeltaT) > timeTol)
+            )
+            {
+                int oldPrecision = precision_;
+                while
+                (
+                    precision_ < maxPrecision_
+                 && readScalar(dimensionedScalar::name(), timeNameValue)
+                 && (mag(-timeNameValue + oldTimeValue - userDeltaT) > timeTol)
+                )
+                {
+                    precision_++;
+                    setTime(value(), timeIndex());
+                }
+
+                if (precision_ != oldPrecision)
+                {
+                    WarningInFunction
+                        << "Increased the timePrecision from " << oldPrecision
+                        << " to " << precision_
+                        << " to distinguish between timeNames at time "
+                        << dimensionedScalar::name()
+                        << endl;
+
+                    if (precision_ == maxPrecision_)
+                    {
+                        // Reached maxPrecision limit
+                        WarningInFunction
+                            << "Current time name " << dimensionedScalar::name()
+                            << nl
+                            << "    The maximum time precision has been reached"
+                               " which might result in overwriting previous"
+                               " results."
+                            << endl;
+                    }
+
+                    // Check if round-off error caused time-reversal
+                    scalar oldTimeNameValue = -VGREAT;
+                    if
+                    (
+                        readScalar(oldTimeName, oldTimeNameValue)
+                     && (
+                            sign(timeNameValue - oldTimeNameValue)
+                         != sign(deltaT_)
+                        )
+                    )
+                    {
+                        WarningInFunction
+                            << "Current time name " << dimensionedScalar::name()
+                            << " is set to an instance prior to the "
+                               "previous one "
+                            << oldTimeName << nl
+                            << "    This might result in temporal "
+                               "discontinuities."
+                            << endl;
+                    }
+                }
+            }
+        }
+    }
+
+    return *this;
+}
+
+
+Foam::Time& Foam::Time::operator--(int)
+{
+    return operator--();
+}
+
+
 // ************************************************************************* //

src/OpenFOAM/db/Time/Time.H

@@ -7,6 +7,7 @@
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
     Copyright (C) 2016-2020 OpenCFD Ltd.
+    Copyright (C) 2022      PCOpt/NTUA
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -571,6 +572,43 @@ public:
             //      not yield the same result
             virtual bool end() const;
 
+            //- Return true if run should continue.
+            //  Does not invoke any functionObject methods
+            //  \note
+            //  For correct behaviour, the following style of time-loop
+            //  is recommended:
+            //  \code
+            //      while (runTime.reverseRun())
+            //      {
+            //          --runTime;
+            //          solve;
+            //          runTime.write();
+            //      }
+            //  \endcode
+            virtual bool reverseRun() const;
+
+            //- Return true if run should continue and if so decrease time
+            //  Does not invoke any functionObject methods
+            //  \note
+            //  For correct behaviour, the following style of time-loop
+            //  is recommended:
+            //  \code
+            //      while (runTime.reverseLoop())
+            //      {
+            //          solve;
+            //          runTime.write();
+            //      }
+            //  \endcode
+            virtual bool reverseLoop();
+
+            //- Return true if end of run,
+            //  does not invoke any functionObject methods
+            //  \note
+            //      The rounding heuristics near endTime mean that
+            //      \code reverseRun() \endcode and \code !reverseEnd() \endcode
+            //      may not yield the same result
+            virtual bool reverseEnd() const;
+
 
         // Edit
 
@@ -653,6 +691,20 @@ public:
 
         //- Postfix increment, this is identical to the prefix increment
         virtual Time& operator++(int);
+
+        //- Set deltaT to that specified and decrease time via operator--()
+        virtual Time& operator-=(const dimensionedScalar& deltaT);
+
+        //- Set deltaT to that specified and decrease time via operator--()
+        virtual Time& operator-=(const scalar deltaT);
+
+        //- prefix decrease,
+        //  also invokes the functionobjectlist::start() or
+        //  functionobjectlist::execute() method, depending on the time-index
+        virtual Time& operator--();
+
+        //- Postfix decrease, this is identical to the decrease increment
+        virtual Time& operator--(int);
 };
 
 

src/OpenFOAM/fields/GeometricFields/GeometricField/GeometricField.C

@@ -545,7 +545,8 @@ Foam::GeometricField<Type, PatchField, GeoMesh>::GeometricField
 (
     const IOobject& io,
     const Mesh& mesh,
-    const dictionary& dict
+    const dictionary& dict,
+    const bool readOldTime
 )
 :
     Internal(io, mesh, dimless, false),
@@ -566,6 +567,11 @@ Foam::GeometricField<Type, PatchField, GeoMesh>::GeometricField
             << exit(FatalIOError);
     }
 
+    if (readOldTime)
+    {
+        readOldTimeIfPresent();
+    }
+
     DebugInFunction
         << "Finishing dictionary-construct" << nl << this->info() << endl;
 }
@@ -623,7 +629,8 @@ template<class Type, template<class> class PatchField, class GeoMesh>
 Foam::GeometricField<Type, PatchField, GeoMesh>::GeometricField
 (
     const IOobject& io,
-    const GeometricField<Type, PatchField, GeoMesh>& gf
+    const GeometricField<Type, PatchField, GeoMesh>& gf,
+    const bool readOldTime
 )
 :
     Internal(io, gf),
@@ -636,7 +643,7 @@ Foam::GeometricField<Type, PatchField, GeoMesh>::GeometricField
         << "Copy construct, resetting IO params" << nl
         << this->info() << endl;
 
-    if (!readIfPresent() && gf.field0Ptr_)
+    if (!readIfPresent() && gf.field0Ptr_ && readOldTime)
     {
         field0Ptr_ = new GeometricField<Type, PatchField, GeoMesh>
         (

src/OpenFOAM/fields/GeometricFields/GeometricField/GeometricField.H

@@ -296,7 +296,8 @@ public:
         (
             const IOobject& io,
             const Mesh& mesh,
-            const dictionary& dict
+            const dictionary& dict,
+            const bool readOldTime = false
         );
 
         //- Copy construct
@@ -315,7 +316,8 @@ public:
         GeometricField
         (
             const IOobject& io,
-            const GeometricField<Type, PatchField, GeoMesh>& gf
+            const GeometricField<Type, PatchField, GeoMesh>& gf,
+            const bool readOldTime = true
         );
 
         //- Construct from tmp\<GeometricField\> resetting IO parameters

src/optimisation/adjointOptimisation/adjoint/Make/files

@@ -1,3 +1,12 @@
+/* COMPRESSION PARAMETERS */
+storage/primalStorage/storageParameters/storageParameters/storageParameters.C
+storage/primalStorage/storageParameters/shortParameters/shortParameters.C
+
+/* COMPRESSED GEOMETRIC FIELD */
+compressedGeometricField = OpenFOAM/fields/compressedGeometricField
+$(compressedGeometricField)/compressedGeometricField/compressedGeometricFields.C
+$(compressedGeometricField)/shortGeometricField/shortGeometricFields.C
+
 /* TURBULENCE MODEL VARIABLE REFS */
 turbulenceModels/turbulenceModelVariables/RAS/RASModelVariables/RASModelVariables.C
 turbulenceModels/turbulenceModelVariables/RAS/laminar/laminar.C
@@ -11,12 +20,29 @@ solvers/variablesSet/variablesSet/variablesSet.C
 solvers/variablesSet/incompressible/incompressibleVars.C
 solvers/variablesSet/incompressibleAdjointMeanFlow/incompressibleAdjointMeanFlowVars.C
 solvers/variablesSet/incompressibleAdjoint/incompressibleAdjointVars.C
+solvers/variablesSet/compressedIncompressible/compressedIncompressibleVars/compressedIncompressibleVars.C
+solvers/variablesSet/compressedIncompressible/shortIncompressibleVars/shortIncompressibleVars.C
+solvers/variablesSet/compressedIncompressible/fullIncompressibleVars/fullIncompressibleVars.C
+solvers/variablesSet/checkPoint/checkPoint.C
 
 /* SOLVER CONTROL */
 solvers/solverControl/solverControl/solverControl.C
 solvers/solverControl/SIMPLEControl/SIMPLEControl/SIMPLEControl.C
 solvers/solverControl/SIMPLEControl/singleRun/SIMPLEControlSingleRun.C
 solvers/solverControl/SIMPLEControl/optimisation/SIMPLEControlOpt.C
+solvers/solverControl/PISOControl/PISOControl/PISOControl.C
+solvers/solverControl/PISOControl/optimisation/PISOControlOpt.C
+solvers/solverControl/PIMPLEControl/PIMPLEControl/PIMPLEControl.C
+solvers/solverControl/PIMPLEControl/optimisation/PIMPLEControlOpt.C
+
+/* STORAGE MANAGMENT */                                                                                                                                                                                   
+storage/primalStorage/primalStorage/primalStorage.C                                                                                                                                                       
+storage/primalStorage/fullStorage/fullStorage.C                                                                                                                                                           
+storage/primalStorage/none/noneStorage.C
+storage/primalStorage/binomialCheckPointing/binomialCheckPointing.C
+compressedFullStorage = storage/primalStorage/compressedFullStorage
+$(compressedFullStorage)/compressedFullStorage/compressedFullStorage.C
+$(compressedFullStorage)/shortFullStorage/shortFullStorage.C
 
 /* SOLVERS */
 solvers/solver/solver.C
@@ -24,9 +50,13 @@ solvers/primalSolvers/primalSolver/primalSolver.C
 solvers/primalSolvers/incompressible/incompressiblePrimalSolver/incompressiblePrimalSolver.C
 solvers/primalSolvers/incompressible/simple/simple.C
 solvers/primalSolvers/incompressible/RASTurbulenceModel/RASTurbulenceModel.C
+solvers/primalSolvers/incompressible/piso/piso.C
+solvers/primalSolvers/incompressible/pimple/pimple.C
 solvers/adjointSolvers/adjointSolver/adjointSolver.C
 solvers/adjointSolvers/incompressible/incompressibleAdjointSolver/incompressibleAdjointSolver.C
 solvers/adjointSolvers/incompressible/adjointSimple/adjointSimple.C
+solvers/adjointSolvers/incompressible/adjointPiso/adjointPiso.C
+solvers/adjointSolvers/incompressible/adjointPimple/adjointPimple.C
 
 /* ADJOINT SOLVER MANAGER */
 solvers/adjointSolverManager/adjointSolverManager.C
@@ -183,5 +213,7 @@ $(incoOptType)/shapeOptimisation/shapeOptimisationIncompressible.C
 optimisation/optimisationManager/optimisationManager/optimisationManager.C
 optimisation/optimisationManager/singleRun/singleRun.C
 optimisation/optimisationManager/steadyOptimisation/steadyOptimisation.C
+optimisation/optimisationManager/unsteadyOptimisation/unsteadyTimeManipulation/unsteadyTimeManipulation.C
+optimisation/optimisationManager/unsteadyOptimisation/unsteadyOptimisation.C
 
 LIB = $(FOAM_LIBBIN)/libadjointOptimisation

src/optimisation/adjointOptimisation/adjoint/OpenFOAM/fields/compressedGeometricField/compressedGeometricField/compressedGeometricField.C

@@ -0,0 +1,612 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "wallFvPatch.H"
+#include "symmetryPlaneFvPatch.H"
+#include "emptyFvsPatchField.H"
+#include "processorFvsPatchField.H"
+#include "coupledFvPatchField.H"
+#include "emptyFvPatchField.H"
+#include "zeroGradientFvPatchField.H"
+#include "inletOutletFvPatchField.H"
+#include "outletInletFvPatchField.H"
+#include "freestreamFvPatchField.H"
+#include "slipFvPatchField.H"
+#include "symmetryFvPatchField.H"
+#include "symmetryPlaneFvPatchField.H"
+#include "cyclicACMIFvPatchField.H"
+#include "bound.H"
+#include "compressedGeometricField.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+label compressedGeometricField<Type, PatchField, GeoMesh>::counter = 0;
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+template<>
+inline scalar&
+compressedGeometricField<scalar, fvPatchField, volMesh>::getValue
+(
+    Field<scalar>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos];
+}
+
+
+template<>
+inline scalar&
+compressedGeometricField<scalar, fvsPatchField, surfaceMesh>::getValue
+(
+    Field<scalar>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos];
+}
+
+
+template<>
+inline scalar&
+compressedGeometricField<vector, fvPatchField, volMesh>::getValue
+(
+    Field<vector>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos][componI];
+}
+
+
+template<>
+inline const scalar&
+compressedGeometricField<scalar, fvPatchField, volMesh>::getValue
+(
+    const Field<scalar>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos];
+}
+
+
+template<>
+inline const scalar&
+compressedGeometricField<scalar, fvsPatchField, surfaceMesh>::getValue
+(
+    const Field<scalar>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos];
+}
+
+
+template<>
+inline const scalar&
+compressedGeometricField<vector, fvPatchField, volMesh>::getValue
+(
+    const Field<vector>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos][componI];
+}
+
+
+template<>
+inline scalar&
+compressedGeometricField<scalar, fvPatchField, volMesh>::getValue
+(
+    List<scalar>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos];
+}
+
+
+template<>
+inline scalar&
+compressedGeometricField<scalar, fvsPatchField, surfaceMesh>::getValue
+(
+    List<scalar>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos];
+}
+
+
+template<>
+inline scalar&
+compressedGeometricField<vector, fvPatchField, volMesh>::getValue
+(
+    List<vector>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos][componI];
+}
+
+
+template<>
+inline const
+scalar& compressedGeometricField<scalar, fvPatchField, volMesh>::getValue
+(
+    const List<scalar>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos];
+}
+
+
+template<>
+inline const
+scalar& compressedGeometricField<scalar, fvsPatchField, surfaceMesh>::getValue
+(
+    const List<scalar>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos];
+}
+
+
+template<>
+inline const
+scalar& compressedGeometricField<vector, fvPatchField, volMesh>::getValue
+(
+    const List<vector>& field,
+    const label& pos,
+    const label& componI
+) const
+{
+    return field[pos][componI];
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void compressedGeometricField<Type, PatchField, GeoMesh>::toBeStored()
+{
+    setValidComponent();
+    toBeStored_.setSize(mesh_.boundary().size(), false);
+    toBeStoredUniformOrNot_.setSize(mesh_.boundary().size(), false);
+    surfacePatchesToBeZeroed_.setSize(mesh_.boundary().size(), false);
+    typedef typename GeometricField<Type, PatchField, GeoMesh>::Boundary
+        Boundary;
+    const Boundary& boundaryField = field_.boundaryField();
+    forAll(mesh_.boundary(), pI)
+    {
+        const PatchField<Type>& pf = boundaryField[pI];
+        if (storageParams_.storeAllBoundaries())
+        {
+            if (pf.size() != 0)
+            {
+                // Warning: Possible error upon compression of boundaries
+                // with very small values when single precision is used.
+                // E.g. flux phi on boundaries with rotatingWallVelocity
+                // for the velocity
+                toBeStoredUniformOrNot_[pI] = true;
+                toBeStored_[pI] = true;
+            }
+        }
+        else
+        {
+            checkFvsPatchFieldStorage(pf, pI);
+            checkFvPatchFieldStorage(pf, pI);
+        }
+        if (debug > 1)
+        {
+            Info<< "Field '" << field_.name() << "': "
+                << "Storing boundary patch " << pI
+                << " '" << mesh_.boundary()[pI].name() << "' "
+                << "of type '" << boundaryField.types()[pI] << "'? "
+                << Switch(toBeStored_[pI]);
+            if (toBeStoredUniformOrNot_[pI] && !toBeStored_[pI])
+            {
+                Info << "  --> Uniform boundary. A single value is stored.";
+            }
+            Info << endl;
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void
+compressedGeometricField<Type, PatchField, GeoMesh>::checkFvsPatchFieldStorage
+(
+    const PatchField<Type>& patchField,
+    const label pI
+)
+{
+    if
+    (
+        isA<fvsPatchField<Type>>(patchField)
+     && !isA<emptyFvsPatchField<Type>>(patchField)
+     && patchField.size()
+    )
+    {
+        toBeStoredUniformOrNot_[pI] = true;
+        // Store processor boundaries even if they are not uniform.
+        // Not sure what will happen at a latter time-step for
+        // compression techniques using time-windows, such as iPGD
+        // Processor check only valid for surfaceFields since volFields
+        // wont enter here due to !isA<coupledFvPatch>
+        if
+        (
+            !patchField.uniform()
+         || storageParams_.storeUniformBoundaries()
+         || isA<processorFvsPatchField<Type>>(patchField)
+        )
+        {
+            toBeStored_[pI] = true;
+        }
+        //  At boundaries with a near-zero value of flux, store a
+        //  (single) zero value for phi. This was added after ZFP
+        //  crashed trying to compress single-precision values of the
+        //  iPGD modes with magnitude below 5.e-30. That problem does
+        //  not arise if these values are represented in
+        //  double-precision. In case that the maximum flux magnitude
+        //  is lower than 1.e-15, it is assumed that the field should
+        //  be zero and the non-zero values arise due to arithmetic
+        //  error. This threshold has been arbitrarily chosen.
+        //  Target  patch types (although not checked in the code):
+        //  wall, symmetryPlane
+
+        //  surfacePatchesToBeZeroed becomes true only in case that phi at the
+        //  corresponding patch must be stored (toBeStoredUniformOrNot = true)
+        //  and is not uniform (patchField.uniform() = false)
+        if (toBeStored_[pI])
+        {
+            // Do the magnitude check here, to avoid unnecessary max
+            // mag calculations
+            if (max(mag(patchField)) < 1.e-15)
+            {
+                toBeStored_[pI] = false;
+                surfacePatchesToBeZeroed_[pI] = true;
+            }
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void
+compressedGeometricField<Type, PatchField, GeoMesh>::checkFvPatchFieldStorage
+(
+    const PatchField<Type>& patchField,
+    const label pI
+)
+{
+    const fvPatch& patch = mesh_.boundary()[pI];
+    if
+    (
+         isA<fvPatchField<Type>>(patchField)
+     && !isA<emptyFvPatchField<Type>>(patchField)
+     && !isA<coupledFvPatchField<Type>>(patchField)
+     && !isA<wallFvPatch>(patch)
+     && !isA<cyclicAMIFvPatchField<Type>>(patchField)
+     && !isA<zeroGradientFvPatchField<Type>>(patchField)
+     && !isA<inletOutletFvPatchField<Type>>(patchField)
+     && !isA<outletInletFvPatchField<Type>>(patchField)
+     && !isA<freestreamFvPatchField<Type>>(patchField)
+     && !isA<slipFvPatchField<Type>>(patchField)
+     && !isA<symmetryFvPatchField<Type>>(patchField)
+     && !isA<symmetryPlaneFvPatchField<Type>>(patchField)
+     &&  patchField.size()
+    )
+    {
+        toBeStoredUniformOrNot_[pI] = true;
+        if (!patchField.uniform() || storageParams_.storeUniformBoundaries())
+        {
+            toBeStored_[pI] = true;
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void compressedGeometricField<Type, PatchField, GeoMesh>::setValidComponent()
+{
+    validCompon_ = 0;
+    if (!solDirs_[0])
+    {
+        validCompon_ = 1;
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void compressedGeometricField<Type, PatchField, GeoMesh>::computeSize()
+{
+    initialSize_ = Zero;
+    uncompressedRoughSize_ = Zero;
+    totalSize_  = Zero;
+    const Field<Type>& internalField = field_.primitiveField();
+    for (label cmptI = 0; cmptI < pTraits<Type>::nComponents; ++cmptI)
+    {
+        initialSize_ += internalField.size()*sizeof(scalar);
+        if (solDirs_[cmptI])
+        {
+            uncompressedRoughSize_ += internalField.size()*sizeof(scalar);
+            totalSize_ += internalField.size();
+        }
+        forAll(mesh_.boundary(), pI)
+        {
+            const Field<Type>& boundaryField = field_.boundaryField()[pI];
+            initialSize_ += boundaryField.size()*sizeof(scalar);
+            if (toBeStored_[pI] && solDirs_[cmptI])
+            {
+                uncompressedRoughSize_ += boundaryField.size()*sizeof(scalar);
+                totalSize_ += boundaryField.size();
+            }
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void compressedGeometricField<Type, PatchField, GeoMesh>::gatherStorageMetrics()
+{
+    if (!timing_)
+    {
+        for (scalar& sm : storageMetrics_)
+        {
+            reduce(sm, sumOp<scalar>());
+        }
+    }
+}
+
+
+template<>
+inline void
+compressedGeometricField<scalar, fvPatchField, volMesh>::handleParticularities
+(
+    volScalarField& field
+)
+{
+    // Due to compression error, turbulence variables might take on
+    // negative values. Correct here
+    // TODO: A little dangerous way to identify turbuelence fields
+    if (iPtr_ == 3 || iPtr_ == 4)
+    {
+        bound(field, dimensionedScalar(field.dimensions(), Zero));
+    }
+}
+
+
+template<>
+inline void
+compressedGeometricField<vector, fvPatchField, volMesh>::handleParticularities
+(
+    volVectorField& field
+)
+{
+    vectorField& internalField = field_.primitiveFieldRef();
+    const labelList& cellIDs = storageParams_.wallList();
+    label cellCounter(0);
+    forAll(cellIDs, i)
+    {
+        vector& vec = internalField[cellIDs[i]];
+        if (mag(vec) < SMALL)
+        {
+            cellCounter++;
+            forAll(vec, j)
+            {
+                if (solDirs_[j])
+                {
+                    vec[j] = SMALL;
+                }
+            }
+        }
+    }
+    DebugInfo
+        << "Modified " << field.name() << " in " << cellCounter
+        << " cell(s) next to wall boundaries" << endl;
+}
+
+
+template<>
+inline void
+compressedGeometricField<scalar, fvsPatchField, surfaceMesh>::handleParticularities
+(
+    surfaceScalarField& field
+)
+{
+    // Does nothing
+}
+
+
+template<>
+inline void compressedGeometricField<scalar, fvPatchField, volMesh>::correctBCs
+(
+    volScalarField& field
+)
+{
+    handleParticularities(field);
+    if (!storageParams_.storeAllBoundaries())
+    {
+        field.correctBoundaryConditions();
+    }
+}
+
+
+template<>
+inline void compressedGeometricField<vector, fvPatchField, volMesh>::correctBCs
+(
+    volVectorField& field
+)
+{
+    handleParticularities(field);
+    if (!storageParams_.storeAllBoundaries())
+    {
+        field.correctBoundaryConditions();
+    }
+}
+
+
+template<>
+inline void
+compressedGeometricField<scalar, fvsPatchField, surfaceMesh>::correctBCs
+(
+    surfaceScalarField& field
+)
+{
+    // Does nothing
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+compressedGeometricField<Type, PatchField, GeoMesh>::compressedGeometricField
+(
+    GeometricField<Type, PatchField, GeoMesh>& field,
+    storageParameters& storageParams,
+    const label iPtr,
+    const label& k
+):
+    field_(field),
+    iPtr_(iPtr),
+
+    dict_(storageParams.dict()),
+    mesh_(field.mesh()),
+    validCompon_(0),
+    k_(k),
+
+    storageParams_(storageParams),
+    timing_(storageParams.timing()),
+    solDirs_(storageParams.solDirs()),
+    eps_(1.e-12),
+
+    storageMetrics_(4, Zero),
+    initialSize_(storageMetrics_[0]),
+    uncompressedRoughSize_(storageMetrics_[1]),
+    uncompressedSize_(storageMetrics_[2]),
+    compressedSize_(storageMetrics_[3]),
+    totalSize_(Zero)
+{
+    if (Pstream::master()) counter++;
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+autoPtr<compressedGeometricField<Type, PatchField, GeoMesh>>
+compressedGeometricField<Type, PatchField, GeoMesh>::New
+(
+    GeometricField<Type, PatchField, GeoMesh>& field,
+    storageParameters& storageParams,
+    const label iPtr,
+    const label& k
+)
+{
+    const word& type = storageParams.compressionMethod()[iPtr];
+    auto cstrIter = dictionaryConstructorTablePtr_->cfind(type);
+
+    if (!cstrIter.found())
+    {
+        FatalIOErrorInFunction(storageParams.dict())
+            << "Unknown compressedGeometricField type " << type << nl << nl
+            << "Valid compressedGeometricField types are :" << nl
+            << dictionaryConstructorTablePtr_->sortedToc()
+            << exit(FatalIOError);
+    }
+
+    return autoPtr<compressedGeometricField<Type, PatchField, GeoMesh>>
+        (cstrIter()( field, storageParams, iPtr, k ));
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void compressedGeometricField<Type, PatchField, GeoMesh>::compress()
+{
+    NotImplemented
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void compressedGeometricField<Type, PatchField, GeoMesh>::decompress
+(
+    GeometricField<Type, PatchField, GeoMesh>& field
+)
+{
+    NotImplemented
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void compressedGeometricField<Type, PatchField, GeoMesh>::decompress()
+{
+    this->decompress(field_);
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+const word& compressedGeometricField<Type, PatchField, GeoMesh>::name() const
+{
+    return field_.name();
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+const scalarList&
+compressedGeometricField<Type, PatchField, GeoMesh>::storageMetrics() const
+{
+    return storageMetrics_;
+}
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/OpenFOAM/fields/compressedGeometricField/compressedGeometricField/compressedGeometricField.H

@@ -0,0 +1,354 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    compressedGeometricField
+
+Description
+    Base class for compression and decompression of the primal fields
+
+SourceFiles
+    compressedGeometricField.C
+
+\*---------------------------------------------------------------------------*/
+
+
+#ifndef compressedGeometricField_H
+#define compressedGeometricField_H
+
+#include "GeometricField.H"
+#include "fieldTypes.H"
+#include "storageParameters.H"
+#include "typeInfo.H"
+#include "runTimeSelectionTables.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                   Class compressedGeometricField Declaration
+\*---------------------------------------------------------------------------*/
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+class compressedGeometricField
+{
+    static label counter;
+
+private:
+
+    // Private Member Functions
+
+        //- No copy construct
+        compressedGeometricField(const compressedGeometricField&) = delete;
+
+        //- No copy assignment
+        void operator=(const compressedGeometricField&) = delete;
+
+
+protected:
+
+    // Protected data
+
+        //- Reference to the field to be compressed,
+        //- i.e. the field used from primalSolver
+        GeometricField<Type, PatchField, GeoMesh>& field_;
+
+        //- Name of the field to be compressed
+        const label iPtr_;
+
+        const dictionary dict_;
+        const fvMesh& mesh_;
+
+        //- Is the first non-empty direction
+        label validCompon_;
+
+        //- Current S/N of the time-step that is compressed in the present
+        //- object
+        const label& k_;
+
+        //- Reference to the compression parameters
+        storageParameters& storageParams_;
+
+        //- Are all unnecessary actions are avoided to benchmark the code?
+        const bool timing_;
+
+        //- The vector of solved-for directions in mesh.
+        //  1 indicates valid direction and -1 an invalid direction.
+        const Vector<label>& solDirs_;
+
+        //- Per patch, whether to store/compress fields using the
+        //- appropriate algorithm.
+        //  Patches with uniform BCs, if a single value is chosen to be
+        //  stored for them, have a false value
+        boolList toBeStored_;
+
+        //- Per patch of a surfaceScalarField, whether they must be zeroed
+        //- upon retrieval.
+        //  To do so a zero value is stored for each of them.
+        boolList surfacePatchesToBeZeroed_;
+
+        //- Per patch, whether to store/compress fields using the
+        //- appropriate algorithm, irrespective of storing a uniform or
+        //- non-uniform value
+        boolList toBeStoredUniformOrNot_;
+
+        //- Threshold to avoid division with Zero
+        scalar eps_;
+
+        //- List holding all of the storageMetrics information
+        scalarList storageMetrics_;
+
+        //- Initial memory size of the field
+        scalar& initialSize_;
+
+        //- Initial memory size of the part of the field, which will be stored
+        //  (e.g. excluding the coupled patches)
+        scalar& uncompressedRoughSize_;
+
+        //- Initial memory size of the part of the field that is sent to Zfp
+        //- compressor.
+        //  It may be larger than uncompressedRoughSize_, if
+        //  rearrangementType=2 and meshMode_=1. Needed to compute the pure
+        //  compression ratio of zfp.
+        scalar& uncompressedSize_;
+
+        //- Compressed memory size of the field
+        scalar& compressedSize_;
+
+        //- Total size of elements at all lists to be compressed
+        label totalSize_;
+
+
+    // Protected Member Functions
+
+        //- Fill in uniformBoundaryValuePtr_ with the uniform boundary field
+        //- values
+        virtual void storeUniformBoundaryValues() = 0;
+
+        //- Restore the uniform boundary field values based on what is stored
+        //- in uniformBoundaryValuePtr_
+        virtual void restoreUniformBoundaryValues
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field
+        ) = 0;
+
+        //- Const and non-const function to return a reference to
+        //- field[pos][componI] for a vectorField and to field[pos] for a
+        //- scalarField
+        inline scalar& getValue
+        (
+            Field<Type>& field,
+            const label& pos,
+            const label& componI
+        ) const;
+
+        inline const scalar& getValue
+        (
+            const Field<Type>& field,
+            const label& pos,
+            const label& componI
+        ) const;
+
+        //- Const and non-const function to return a reference to
+        //- field[pos][componI] for a List<vector> and to field[pos] for a
+        //- List<scalar>
+        inline scalar& getValue
+        (
+            List<Type>& field,
+            const label& pos,
+            const label& componI
+        ) const;
+
+        inline const scalar& getValue
+        (
+            const List<Type>& field,
+            const label& pos,
+            const label& componI
+        ) const;
+
+        //- Fill in toBeSorted_ which defines if the scalarField component of
+        //- a boundary condition must be stored or not, per patch
+        //  (empty, coupled and zero sized patches do not get stored)
+        virtual void toBeStored();
+
+        //- Since partial template specialization is not allowed,
+        //- define two different functions with the same arguments
+        //- and specialize checks there
+        void checkFvsPatchFieldStorage
+        (
+            const PatchField<Type>& patchField,
+            const label pI
+        );
+
+        void checkFvPatchFieldStorage
+        (
+            const PatchField<Type>& patchField,
+            const label patchI
+        );
+
+        //- Compute initial size of the field to be compressed
+        void computeSize();
+
+        //- Construct a list containing all of the compression metrics
+        void gatherStorageMetrics();
+
+        //- Set a valid solution direction
+        void setValidComponent();
+
+        //- Called before correcting the BCs
+        //  The function is specialized for the different geometric fields.
+        inline void handleParticularities
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field
+        );
+
+        //- Correct boundary conditions of coupled patches.
+        //  The function is specialized for the different geometric fields.
+        inline void correctBCs
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field
+        );
+
+
+public:
+
+    //- Runtime type information
+    TypeName("compressedGeometricField");
+
+    // Declare run-time constructor selection tables
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            compressedGeometricField,
+            dictionary,
+            (
+                GeometricField<Type, PatchField, GeoMesh>& field,
+                storageParameters& storageParams,
+                const label iPtr,
+                const label& k
+            ),
+            (field, storageParams, iPtr, k)
+        );
+
+
+    // Constructors
+    compressedGeometricField
+    (
+        GeometricField<Type, PatchField, GeoMesh>& field,
+        storageParameters& storageParams,
+        const label iPtr,
+        const label& k
+    );
+
+
+    // Destructors
+    virtual ~compressedGeometricField() = default;
+
+
+    // Selectors
+
+        //- Return a pointer to a new compressedGeometricField
+        static autoPtr<compressedGeometricField<Type, PatchField, GeoMesh>> New
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field,
+            storageParameters& storageParams,
+            const label iPtr,
+            const label& k
+        );
+
+
+    // Member Functions
+
+        //- Compress the field
+        virtual void compress();
+
+        //- Decompress the field
+        virtual void decompress
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field
+        );
+
+        void decompress();
+
+        const word& name() const;
+
+        //- Get a const reference to the compression metrics
+        virtual const scalarList& storageMetrics() const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "compressedGeometricField.C"
+#endif
+
+
+// Add the patch constructor functions to the hash tables
+
+#define makeCompressedGeometricTypeField(SS, Type, PatchField, GeoMesh)        \
+    typedef SS<Type, PatchField, GeoMesh>                                      \
+        SS##Type##PatchField##GeoMesh##_;                                      \
+                                                                               \
+    defineNamedTemplateTypeNameAndDebug                                        \
+        (SS##Type##PatchField##GeoMesh##_, 0);                                 \
+                                                                               \
+    compressedGeometricField<Type, PatchField, GeoMesh>                        \
+    ::adddictionaryConstructorToTable<SS<Type, PatchField, GeoMesh>>           \
+        add##SS##Type##PatchField##GeoMesh##dictionaryConstructorToTable_;     \
+
+#define makeCompressedGeometricTypeFieldNoAdd(SS, Type, PatchField, GeoMesh)   \
+    typedef SS<Type, PatchField, GeoMesh>                                      \
+        SS##Type##PatchField##GeoMesh##_;                                      \
+                                                                               \
+    defineNamedTemplateTypeNameAndDebug                                        \
+        (SS##Type##PatchField##GeoMesh##_, 0);
+
+#define makeCompressedGeometricField(SS)                                       \
+                                                                               \
+makeCompressedGeometricTypeField(SS, scalar, fvPatchField,  volMesh)           \
+makeCompressedGeometricTypeField(SS, scalar, fvsPatchField, surfaceMesh)       \
+makeCompressedGeometricTypeField(SS, vector, fvPatchField,  volMesh)
+
+#define makeCompressedGeometricFieldNoAdd(SS)                                  \
+                                                                               \
+makeCompressedGeometricTypeFieldNoAdd(SS, scalar, fvPatchField,  volMesh)      \
+makeCompressedGeometricTypeFieldNoAdd(SS, scalar, fvsPatchField, surfaceMesh)  \
+makeCompressedGeometricTypeFieldNoAdd(SS, vector, fvPatchField,  volMesh)
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/OpenFOAM/fields/compressedGeometricField/compressedGeometricField/compressedGeometricFields.C

@@ -0,0 +1,51 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Released 2004-2011 OpenCFD Ltd.
+    Copyright (C) 2011-2012 OpenFOAM Foundation
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "compressedGeometricFields.H"
+#include "HashTable.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+// Define the constructor function hash tables
+
+defineNamedTemplateTypeNameAndDebug(compressedVolScalarField, 0);
+defineTemplateRunTimeSelectionTable(compressedVolScalarField, dictionary);
+
+defineNamedTemplateTypeNameAndDebug(compressedSurfaceScalarField, 0);
+defineTemplateRunTimeSelectionTable(compressedSurfaceScalarField, dictionary);
+
+defineNamedTemplateTypeNameAndDebug(compressedVolVectorField, 0);
+defineTemplateRunTimeSelectionTable(compressedVolVectorField, dictionary);
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/OpenFOAM/fields/compressedGeometricField/compressedGeometricField/compressedGeometricFields.H

@@ -0,0 +1,39 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Released 2004-2011 OpenCFD Ltd.
+    Copyright (C) 2011 OpenFOAM Foundation
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef compressedGeometricFields_H
+#define compressedGeometricFields_H
+
+#include "compressedGeometricField.H"
+#include "compressedGeometricFieldsFwd.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/OpenFOAM/fields/compressedGeometricField/compressedGeometricField/compressedGeometricFieldsFwd.H

@@ -0,0 +1,61 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    compressedGeometricField
+
+
+\*---------------------------------------------------------------------------*/
+
+
+#ifndef compressedGeometricFieldsFwd_H
+#define compressedGeometricFieldsFwd_H
+
+#include "fieldTypes.H"
+#include "fvPatchField.H"
+#include "wordList.H"
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+class compressedGeometricField;
+
+typedef compressedGeometricField<scalar, fvPatchField,  volMesh>     compressedVolScalarField;
+typedef compressedGeometricField<scalar, fvsPatchField, surfaceMesh> compressedSurfaceScalarField;
+typedef compressedGeometricField<vector, fvPatchField,  volMesh>     compressedVolVectorField;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/OpenFOAM/fields/compressedGeometricField/shortGeometricField/shortGeometricField.C

@@ -0,0 +1,254 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "shortGeometricField.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void
+shortGeometricField<Type, PatchField, GeoMesh>::storeUniformBoundaryValues()
+{
+    forAll(uniformBoundaryValuePtr_, pI)
+    {
+        const Field<Type>& boundaryField = this->field_.boundaryField()[pI];
+        if (this->toBeStoredUniformOrNot_[pI] && !this->toBeStored_[pI])
+        {
+            if
+            (
+                std::is_same<PatchField<Type>, fvsPatchField<Type>>::value
+            &&  this->surfacePatchesToBeZeroed_[pI]
+            )
+            {
+                // At this point, the maximum magnitude of the boundaryField is
+                // for sure below the prescribed threshold
+                uniformBoundaryValuePtr_.set(pI, new Type(Zero));
+            }
+            else
+            {
+                uniformBoundaryValuePtr_.set
+                (
+                    pI, new Type(boundaryField.first())
+                );
+            }
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void
+shortGeometricField<Type, PatchField, GeoMesh>::restoreUniformBoundaryValues
+(
+    GeometricField<Type, PatchField, GeoMesh>& field
+)
+{
+    forAll(uniformBoundaryValuePtr_, pI)
+    {
+        Field<Type>& boundaryField = field.boundaryFieldRef()[pI];
+        if (uniformBoundaryValuePtr_(pI))
+        {
+            boundaryField = uniformBoundaryValuePtr_[pI];
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void shortGeometricField<Type, PatchField, GeoMesh>::initialize()
+{
+    this->toBeStored();
+    this->computeSize();
+    this->uncompressedSize_ = this->uncompressedRoughSize_;
+    this->compressedSize_ = this->uncompressedRoughSize_;
+    setBuffers();
+    storeUniformBoundaryValues();
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void shortGeometricField<Type, PatchField, GeoMesh>::setBuffers()
+{
+    const Field<Type>& internalField = this->field_.primitiveField();
+    forAll(internalBufferPtr_, cmptI)
+    {
+        if (this->solDirs_[cmptI])
+        {
+            internalBufferPtr_[cmptI].setSize(internalField.size());
+        }
+    }
+    forAll (boundaryBufferPtr_, pI)
+    {
+        if (this->toBeStored_[pI])
+        {
+            boundaryBufferPtr_[pI].setSize(pTraits<Type>::nComponents);
+            const Field<Type>& boundaryField = this->field_.boundaryField()[pI];
+            forAll(boundaryBufferPtr_[pI], cmptI)
+            {
+                if (this->solDirs_[cmptI])
+                {
+                    boundaryBufferPtr_[pI][cmptI].setSize(boundaryField.size());
+                }
+            }
+        }
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+shortGeometricField<Type, PatchField, GeoMesh>::shortGeometricField
+(
+    GeometricField<Type, PatchField, GeoMesh>& field,
+    storageParameters& storageParams,
+    const label iPtr,
+    const label& k
+):
+    compressedGeometricField<Type, PatchField, GeoMesh>
+    (
+        field,
+        storageParams,
+        iPtr,
+        k
+    ),
+    internalBufferPtr_(pTraits<Type>::nComponents),
+    boundaryBufferPtr_(field.mesh().boundary().size()),
+    uniformBoundaryValuePtr_(field.mesh().boundary().size())
+{
+    initialize();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void shortGeometricField<Type, PatchField, GeoMesh>::compress()
+{
+    const Field<Type>& internalField = this->field_.primitiveField();
+    forAll(internalBufferPtr_, cmptI)
+    {
+        if (this->solDirs_[cmptI])
+        {
+            forAll(internalBufferPtr_[cmptI], iPtr)
+            {
+                internalBufferPtr_[cmptI][iPtr] =
+                    this->getValue(internalField, iPtr, cmptI);
+            }
+        }
+    }
+    forAll(boundaryBufferPtr_, pI)
+    {
+        if (this->toBeStored_[pI])
+        {
+            const Field<Type>& boundaryField = this->field_.boundaryField()[pI];
+            for (label cmptI = 0; cmptI < pTraits<Type>::nComponents; ++cmptI)
+            {
+                if (this->solDirs_[cmptI])
+                {
+                    forAll(boundaryBufferPtr_[pI][cmptI], iPtr)
+                    {
+                        boundaryBufferPtr_[pI][cmptI][iPtr] =
+                            this->getValue(boundaryField, iPtr, cmptI);
+                    }
+                }
+            }
+        }
+    }
+    this->gatherStorageMetrics();
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void shortGeometricField<Type, PatchField, GeoMesh>::decompress
+(
+    GeometricField<Type, PatchField, GeoMesh>& field
+)
+{
+    Field<Type>& internalField = field.primitiveFieldRef();
+    forAll(internalBufferPtr_, cmptI)
+    {
+        if (this->solDirs_[cmptI])
+        {
+            forAll(internalBufferPtr_[cmptI], iPtr)
+            {
+                scalar& val = this->getValue(internalField, iPtr, cmptI);
+                val = internalBufferPtr_[cmptI][iPtr];
+            }
+        }
+        /*else
+        {
+            forAll(internalBufferPtr_[cmptI], iPtr)
+            {
+                scalar& val = this->getValue(internalField, iPtr, cmptI);
+                val = 0;
+            }
+        }*/
+    }
+    forAll(boundaryBufferPtr_, pI)
+    {
+        if (this->toBeStored_[pI])
+        {
+            Field<Type>& boundaryField = field.boundaryFieldRef()[pI];
+            for (label cmptI = 0; cmptI < pTraits<Type>::nComponents; ++cmptI)
+            {
+                if (this->solDirs_[cmptI])
+                {
+                    forAll(boundaryBufferPtr_[pI][cmptI], iPtr)
+                    {
+                        scalar& val =
+                            this->getValue(boundaryField, iPtr, cmptI);
+                        val = boundaryBufferPtr_[pI][cmptI][iPtr];
+                    }
+                }
+                /*else
+                {
+                    forAll (boundaryBufferPtr_[pI], iPtr)
+                    {
+                        scalar& val = this->getValue(boundaryField, iPtr, cmptI);
+                        val = 0;
+                    }
+                }*/
+            }
+        }
+    }
+    this->restoreUniformBoundaryValues(field);
+    this->correctBCs(field);
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/OpenFOAM/fields/compressedGeometricField/shortGeometricField/shortGeometricField.H

@@ -0,0 +1,142 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    shortGeometricField
+
+Description
+    Stores only the current state of a GeometricField (i.e. not oldTimes).
+    Additionally, avoids storing patchFields that can be retrieved through
+    correctBoundaryConditions (e.g. uniform fields, coupled, symmetry, etc)
+
+SourceFiles
+    shortGeometricField.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef shortGeometricField_H
+#define shortGeometricField_H
+
+#include "compressedGeometricField.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                     Class shortGeometricField Declaration
+\*---------------------------------------------------------------------------*/
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+class shortGeometricField
+:
+    public compressedGeometricField<Type, PatchField, GeoMesh>
+{
+protected:
+
+    // Protected data
+
+        //- Storage of the internalField deceomposed into multiple
+        //- scalarFields
+        List<scalarField> internalBufferPtr_;
+
+        //- Storage of the boundaryField deceomposed into multiple
+        //- scalarFields per patch
+        List<List<scalarField>> boundaryBufferPtr_;
+
+        //- Holds the uniform value for patches with such boundary conditions.
+        //  Allocated only on these patches
+        PtrList<Type> uniformBoundaryValuePtr_;
+
+
+    // Protected Member Functions
+
+        //- Fill in uniformBoundaryValuePtr_ with the uniform boundary field
+        //- values
+        void storeUniformBoundaryValues() override;
+
+        //- Restore the uniform boundary field values based on what is stored
+        //- in uniformBoundaryValuePtr_
+        void restoreUniformBoundaryValues
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field
+        ) override;
+
+        //- Initialize necessary parameters
+        void initialize();
+
+        //- Set sizes for internalBufferPtr_ and boundaryBufferPtr_
+        void setBuffers();
+
+
+public:
+
+    //- Runtime type information
+    TypeName("shortGeometricField");
+
+
+    // Constructors
+    shortGeometricField
+    (
+        GeometricField<Type, PatchField, GeoMesh>& field,
+        storageParameters& storageParams,
+        const label iPtr,
+        const label& k
+    );
+
+
+    // Destructors
+    virtual ~shortGeometricField() = default;
+
+
+    // Member Functions
+
+        //- Store field
+        void compress() override;
+
+        //- Retrieve field
+        void decompress
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field
+        ) override;
+};
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "shortGeometricField.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/OpenFOAM/fields/compressedGeometricField/shortGeometricField/shortGeometricFields.C

@@ -0,0 +1,45 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "shortGeometricField.H"
+#include "HashTable.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+makeCompressedGeometricField(shortGeometricField)
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/objectiveManager/objectiveManager/objectiveManager.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2021 PCOpt/NTUA
-    Copyright (C) 2013-2021 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -67,7 +67,8 @@ objectiveManager::objectiveManager
     adjointSolverName_(adjointSolverName),
     primalSolverName_(primalSolverName),
     objectives_(0),
-    weigthedObjectiveFile_(nullptr)
+    weigthedObjectiveFile_(nullptr),
+    hasIntegrationTimes_(true)
 {
     // Construct objectives
     //~~~~~~~~~~~~~~~~~~~~~
@@ -182,6 +183,12 @@ bool objectiveManager::readDict(const dictionary& dict)
 }
 
 
+bool objectiveManager::hasIntegrationTimes() const
+{
+    return hasIntegrationTimes_;
+}
+
+
 void objectiveManager::updateNormalizationFactor()
 {
     // Update normalization factors for all objectives
@@ -252,6 +259,24 @@ scalar objectiveManager::print()
 }
 
 
+void objectiveManager::setWrite(const bool shouldWrite)
+{
+    for (objective& obj : objectives_)
+    {
+        obj.setWrite(shouldWrite);
+    }
+}
+
+
+void objectiveManager::setWriteOption(IOobject::writeOption w)
+{
+    for (objective& obj : objectives_)
+    {
+        obj.setWriteOption(w);
+    }
+}
+
+
 bool objectiveManager::writeObjectives
 (
     const scalar weightedObjective,
@@ -261,8 +286,8 @@ bool objectiveManager::writeObjectives
     for (const objective& obj : objectives_)
     {
         // Write objective function to file
-        obj.write();
-        obj.writeMeanValue();
+            obj.write();
+            obj.writeMeanValue();
     }
 
     if (weigthedObjectiveFile_.valid())
@@ -317,16 +342,13 @@ const word& objectiveManager::primalSolverName() const
 }
 
 
-void objectiveManager::checkIntegrationTimes() const
+void objectiveManager::checkIntegrationTimes()
 {
     for (const objective& obj : objectives_)
     {
         if (!obj.hasIntegrationStartTime() || !obj.hasIntegrationEndTime())
         {
-            FatalErrorInFunction()
-                << "Objective function " << obj.objectiveName()
-                << " does not have a defined integration start or end time "
-                << exit(FatalError);
+            hasIntegrationTimes_ = false;
         }
     }
 }

src/optimisation/adjointOptimisation/adjoint/objectiveManager/objectiveManager/objectiveManager.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2021 PCOpt/NTUA
-    Copyright (C) 2013-2021 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -66,6 +66,7 @@ protected:
         const word primalSolverName_;
         PtrList<objective> objectives_;
         autoPtr<OFstream> weigthedObjectiveFile_;
+        bool hasIntegrationTimes_;
 
 
 private:
@@ -130,6 +131,12 @@ public:
 
         virtual bool readDict(const dictionary& dict);
 
+        //- Boolean defining if all objectives have defined their integration
+        //  window.
+        //  false if at least one of the objectives has an undefined
+        //  integration window
+        bool hasIntegrationTimes() const;
+
         //- Update objective function related values
         void updateNormalizationFactor();
 
@@ -145,6 +152,12 @@ public:
         //- Print to screen
         scalar print();
 
+        //- Set write option for objectives (files in the optimisation folder)
+        void setWrite(const bool shouldWrite);
+
+        //- Set write option for the localIOdictionary base of the objectives
+        void setWriteOption(IOobject::writeOption w);
+
         //- Write objective function history
         virtual bool writeObjectives
         (
@@ -172,7 +185,7 @@ public:
         const word& primalSolverName() const;
 
         //- Check integration times for unsteady runs
-        void checkIntegrationTimes() const;
+        void checkIntegrationTimes();
 
         //- Add contribution to adjoint momentum PDEs
         virtual void addUaEqnSource(fvVectorMatrix& UaEqn) = 0;

src/optimisation/adjointOptimisation/adjoint/objectives/objective/objective.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2020 PCOpt/NTUA
-    Copyright (C) 2013-2020 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -131,6 +131,7 @@ objective::objective
     computeMeanFields_(false), // is reset in derived classes
     nullified_(false),
     normalize_(dict.getOrDefault<bool>("normalize", false)),
+    shouldWrite_(true),
 
     J_(Zero),
     JMean_(this->getOrDefault<scalar>("JMean", Zero)),
@@ -172,14 +173,22 @@ objective::objective
     {
         integrationStartTimePtr_.reset
         (
-            new scalar(dict.get<scalar>("integrationStartTime"))
+            new scalar
+            (
+                dict.get<scalar>("integrationStartTime") +
+                mesh_.time().value()
+            )
         );
     }
     if (dict.found("integrationEndTime"))
     {
         integrationEndTimePtr_.reset
         (
-            new scalar(dict.get<scalar>("integrationEndTime"))
+            new scalar
+            (
+                dict.get<scalar>("integrationEndTime") +
+                mesh_.time().value()
+            )
         );
     }
 
@@ -299,17 +308,22 @@ void objective::accumulateJMean(solverControl& solverControl)
 }
 
 
+void objective::resetJMean()
+{
+    JMean_ = 0;
+}
+
+
 void objective::accumulateJMean()
 {
     if (hasIntegrationStartTime() && hasIntegrationEndTime())
     {
-        const scalar time = mesh_.time().value();
         if (isWithinIntegrationTime())
         {
-            const scalar dt = mesh_.time().deltaT().value();
-            const scalar elapsedTime = time - integrationStartTimePtr_();
-            const scalar denom = elapsedTime + dt;
-            JMean_ = (JMean_*elapsedTime + J_*dt)/denom;
+            const scalar dt = mesh_.time().deltaTValue();
+            const scalar elapsedTime
+                = mesh_.time().value() - integrationStartTimePtr_();
+            JMean_ = (JMean_*elapsedTime + J_*dt)/(elapsedTime + dt);
         }
     }
     else
@@ -384,10 +398,11 @@ bool objective::isWithinIntegrationTime() const
     if (hasIntegrationStartTime() && hasIntegrationEndTime())
     {
         const scalar time = mesh_.time().value();
+        const scalar dt = mesh_.time().deltaTValue();
         return
             (
-                time >= integrationStartTimePtr_()
-             && time <= integrationEndTimePtr_()
+                time >= (integrationStartTimePtr_() - 0.1*dt)
+             && time <= (integrationEndTimePtr_()   + 1.1*dt)
             );
     }
     else
@@ -413,6 +428,8 @@ void objective::incrementIntegrationTimes(const scalar timeSpan)
             << "Unallocated integration start or end time"
             << exit(FatalError);
     }
+    // Set nullified_ to false for the next optimization cycle
+    nullified_ = false;
 }
 
 
@@ -659,7 +676,7 @@ void objective::nullify()
 
 bool objective::write(const bool valid) const
 {
-    if (Pstream::master())
+    if (Pstream::master() && shouldWrite_)
     {
         // File is opened only upon invocation of the write function
         // in order to avoid various instantiations of the same objective
@@ -732,7 +749,7 @@ void objective::writeInstantaneousSeparator() const
 
 void objective::writeMeanValue() const
 {
-    if (Pstream::master())
+    if (Pstream::master() && shouldWrite_)
     {
         // Write mean value if necessary
         // Covers both steady and unsteady runs
@@ -742,8 +759,8 @@ void objective::writeMeanValue() const
          || (hasIntegrationStartTime() && hasIntegrationEndTime())
         )
         {
-            // File is opened only upon invocation of the write function
-            // in order to avoid various instantiations of the same objective
+            // File is opened only upon invocation of the write function in
+            // order to avoid various instantiations of the same objective
             // opening the same file
             if (!meanValueFilePtr_)
             {

src/optimisation/adjointOptimisation/adjoint/objectives/objective/objective.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2020 PCOpt/NTUA
-    Copyright (C) 2013-2020 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -73,6 +73,7 @@ protected:
         bool computeMeanFields_;
         bool nullified_;
         bool normalize_;
+        bool shouldWrite_;
 
         //- Objective function value and weight
         scalar J_;
@@ -253,6 +254,9 @@ public:
         //  For unsteady runs
         void accumulateJMean();
 
+        //- Nullify JMean. To be used in unsteady optimization.
+        void resetJMean();
+
         //- Return the objective function weight
         scalar weight() const;
 
@@ -392,6 +396,15 @@ public:
         //- Return the objective name
         inline const word& objectiveName() const;
 
+        //- Should the objective be written to file upon calling write()?
+        inline bool shouldWrite() const;
+
+        //- Set the shouldWrite_ flag (files in the optimisation folder)
+        inline void setWrite(const bool shouldWrite);
+
+        //- Set the write option of the base localIOdictionary
+        inline void setWriteOption(IOobject::writeOption w);
+
         // Inline functions for checking whether pointers are set or not
         inline bool hasdJdb() const;
         inline bool hasBoundarydJdb() const;

src/optimisation/adjointOptimisation/adjoint/objectives/objective/objectiveI.H

@@ -36,6 +36,24 @@ inline const Foam::word& Foam::objective::objectiveName() const
 }
 
 
+inline bool Foam::objective::shouldWrite() const
+{
+    return shouldWrite_;
+}
+
+
+inline void Foam::objective::setWrite(const bool shouldWrite)
+{
+    shouldWrite_ = shouldWrite;
+}
+
+
+inline void Foam::objective::setWriteOption(IOobject::writeOption w)
+{
+    IOobject::writeOpt() = w;
+}
+
+
 inline bool Foam::objective::hasdJdb() const
 {
     return bool(dJdbPtr_);

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/optimisationManager/optimisationManager.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -38,28 +38,137 @@ namespace Foam
 }
 
 
-// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
 
-Foam::optimisationManager::optimisationManager(fvMesh& mesh)
-:
-    IOdictionary
-    (
-        IOobject
-        (
-            "optimisationDict",
-            mesh.time().system(),
-            mesh,
-            IOobject::MUST_READ_IF_MODIFIED,
-            IOobject::NO_WRITE,
-            true
-        )
-    ),
-    mesh_(mesh),
-    time_(const_cast<Time&>(mesh.time())),
-    primalSolvers_(),
-    adjointSolverManagers_(),
-    managerType_(get<word>("optimisationManager")),
-    optType_(nullptr)
+void Foam::optimisationManager::resetTime()
+{
+    // Does nothing in base
+}
+
+
+void Foam::optimisationManager::lineSearchUpdate()
+{
+    // Compute direction of update
+    tmp<scalarField> tdirection = optType_->computeDirection();
+    scalarField& direction = tdirection.ref();
+
+    // Grab reference to line search
+    autoPtr<lineSearch>& lineSrch = optType_->getLineSearch();
+
+    // Store starting point
+    optType_->storeDesignVariables();
+
+    // Compute merit function before update
+    scalar meritFunction = optType_->computeMeritFunction();
+    lineSrch->setOldMeritValue(meritFunction);
+
+    // Get merit function derivative
+    const scalar dirDerivative =
+        optType_->meritFunctionDirectionalDerivative();
+    lineSrch->setDeriv(dirDerivative);
+    lineSrch->setDirection(direction);
+
+    // Reset initial step.
+    // Might be interpolated from previous optimisation cycles
+    lineSrch->reset();
+
+    // Perform line search
+    for (label iter = 0; iter < lineSrch->maxIters(); ++iter)
+    {
+        Info<< "\n- - - - - - - - - - - - - - -"  << endl;
+        Info<< "Line search iteration "   << iter << endl;
+        Info<< "- - - - - - - - - - - - - - -\n"  << endl;
+
+        // Update design variables. Multiplication with line search step
+        // happens inside the update(direction) function
+        moveDesignVariables(direction);
+
+        // Solve all primal equations
+        solvePrimalEquations();
+
+        // Compute and set new merit function
+        meritFunction = optType_->computeMeritFunction();
+        lineSrch->setNewMeritValue(meritFunction);
+
+        if (lineSrch->converged())
+        {
+            // If line search criteria have been met, proceed
+            Info<< "Line search converged in " << iter + 1
+                << " iterations." << endl;
+            scalarField scaledCorrection(lineSrch->step()*direction);
+            optType_->updateOldCorrection(scaledCorrection);
+            optType_->write();
+            lineSrch()++;
+            postUpdate();
+            break;
+        }
+        else
+        {
+            // If maximum number of iteration has been reached, continue
+            if (iter == lineSrch->maxIters() - 1)
+            {
+                Info<< "Line search reached max. number of iterations.\n"
+                    << "Proceeding to the next optimisation cycle" << endl;
+                scalarField scaledCorrection(lineSrch->step()*direction);
+                optType_->updateOldCorrection(scaledCorrection);
+                optType_->write();
+                lineSrch()++;
+                postUpdate();
+            }
+            // Reset to initial design variables and update step
+            else
+            {
+                resetTime();
+                optType_->resetDesignVariables();
+                lineSrch->updateStep();
+            }
+        }
+    }
+}
+
+
+void Foam::optimisationManager::fixedStepUpdate()
+{
+    moveDesignVariables();
+
+    // Solve primal equations
+    solvePrimalEquations();
+    postUpdate();
+}
+
+
+void Foam::optimisationManager::postUpdate()
+{
+    for (primalSolver& solver : primalSolvers_)
+    {
+        solver.postLineSearch();
+    }
+
+    for (adjointSolverManager& manager : adjointSolverManagers_)
+    {
+        manager.postLineSearch();
+    }
+}
+
+
+void Foam::optimisationManager::moveDesignVariables()
+{
+    // Update design variables
+    optType_->update();
+}
+
+
+void Foam::optimisationManager::moveDesignVariables
+(
+    scalarField& direction
+)
+{
+    // Update design variables
+    optType_->update(direction);
+}
+
+
+void Foam::optimisationManager::initialize()
 {
     dictionary& primalSolversDict = subDict("primalSolvers");
     const wordList& primalSolverNames = primalSolversDict.toc();
@@ -79,7 +188,7 @@ Foam::optimisationManager::optimisationManager(fvMesh& mesh)
             solveri,
             primalSolver::New
             (
-                mesh,
+                mesh_,
                 managerType_,
                 solverDict
             )
@@ -100,7 +209,7 @@ Foam::optimisationManager::optimisationManager(fvMesh& mesh)
             manageri,
             new adjointSolverManager
             (
-                mesh,
+                mesh_,
                 managerType_,
                 adjointManagersDict.subDict(adjointManagerNames[manageri]),
                 overrideUseSolverName
@@ -148,6 +257,33 @@ Foam::optimisationManager::optimisationManager(fvMesh& mesh)
 }
 
 
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::optimisationManager::optimisationManager(fvMesh& mesh)
+:
+    IOdictionary
+    (
+        IOobject
+        (
+            "optimisationDict",
+            mesh.time().system(),
+            mesh,
+            IOobject::MUST_READ_IF_MODIFIED,
+            IOobject::NO_WRITE,
+            true
+        )
+    ),
+    mesh_(mesh),
+    time_(const_cast<Time&>(mesh.time())),
+    primalSolvers_(),
+    adjointSolverManagers_(),
+    managerType_(get<word>("optimisationManager")),
+    optType_(nullptr),
+    shouldUpdateDesignVariables_(true)
+{
+}
+
+
 // * * * * * * * * * * * * * * * * Selectors  * * * * * * * * * * * * * * //
 
 Foam::autoPtr<Foam::optimisationManager> Foam::optimisationManager::New
@@ -215,6 +351,24 @@ bool Foam::optimisationManager::read()
 }
 
 
+void Foam::optimisationManager::updateDesignVariables()
+{
+    // Update design variables using either a line-search scheme or
+    // a fixed-step update
+    if (optType_->getLineSearch())
+    {
+        lineSearchUpdate();
+    }
+    else
+    {
+        fixedStepUpdate();
+    }
+
+    // Reset adjoint sensitivities in all adjoint solver managers
+    clearSensitivities();
+}
+
+
 Foam::PtrList<Foam::primalSolver>& Foam::optimisationManager::primalSolvers()
 {
     return primalSolvers_;
@@ -230,10 +384,9 @@ Foam::optimisationManager::adjointSolverManagers()
 
 void Foam::optimisationManager::solvePrimalEquations()
 {
-    // Solve all primal equations
-    forAll(primalSolvers_, psI)
+    for (primalSolver& solver : primalSolvers_)
     {
-        primalSolvers_[psI].solve();
+        solver.solve();
     }
 }
 
@@ -241,9 +394,9 @@ void Foam::optimisationManager::solvePrimalEquations()
 void Foam::optimisationManager::solveAdjointEquations()
 {
     // Solve all adjoint solver equations
-    forAll(adjointSolverManagers_, amI)
+    for (adjointSolverManager& manager : adjointSolverManagers_)
     {
-        adjointSolverManagers_[amI].solveAdjointEquations();
+        manager.solveAdjointEquations();
     }
 }
 
@@ -258,6 +411,15 @@ void Foam::optimisationManager::computeSensitivities()
 }
 
 
+void Foam::optimisationManager::clearSensitivities()
+{
+    for (adjointSolverManager& adjSolvManager : adjointSolverManagers_)
+    {
+        adjSolvManager.clearSensitivities();
+    }
+}
+
+
 void Foam::optimisationManager::updatePrimalBasedQuantities()
 {
     forAll(adjointSolverManagers_, amI)

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/optimisationManager/optimisationManager.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2e22 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -68,8 +68,37 @@ protected:
         PtrList<primalSolver> primalSolvers_;
         PtrList<adjointSolverManager> adjointSolverManagers_;
         const word managerType_;
+
         autoPtr<incompressible::optimisationType> optType_;
 
+        Switch shouldUpdateDesignVariables_;
+
+
+    // Protected Member Functions
+
+        virtual void resetTime();
+
+        //- Update design variables
+        virtual void moveDesignVariables();
+
+        //- Update design variables. Multiplication with line search step
+        //- happens inside the update(direction) function
+        virtual void moveDesignVariables
+        (
+            scalarField& direction
+        );
+
+        //- Update design variables using a line-search
+        void lineSearchUpdate();
+
+        //- Update design variables using a fixed step
+        void fixedStepUpdate();
+
+        //- Actions performed after lineSearch has converged
+        void postUpdate();
+
+        //- Initialization. Construct primal and adjoint solvers
+        virtual void initialize();
 
 private:
 
@@ -145,7 +174,7 @@ public:
         //- Update design variables.
         //  Might employ a line search to find a correction satisfying the step
         //  convergence criteria
-        virtual void updateDesignVariables() = 0;
+        virtual void updateDesignVariables();
 
         //- Solve all primal equations
         virtual void solvePrimalEquations();
@@ -156,6 +185,9 @@ public:
         //- Compute all adjoint sensitivities
         virtual void computeSensitivities();
 
+        //- Clear all adjoint sensitivities
+        virtual void clearSensitivities();
+
         //- Solve all primal equations
         virtual void updatePrimalBasedQuantities();
 };

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/singleRun/singleRun.C

@@ -45,7 +45,9 @@ Foam::singleRun::singleRun(fvMesh& mesh)
 :
     optimisationManager(mesh),
     cycles_(Zero)
-{}
+{
+    initialize();
+}
 
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/steadyOptimisation/steadyOptimisation.C

@@ -66,102 +66,13 @@ void Foam::steadyOptimisation::updateOptTypeSource()
 }
 
 
-// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
-
-void Foam::steadyOptimisation::lineSearchUpdate()
-{
-    // Compute direction of update
-    tmp<scalarField> tdirection = optType_->computeDirection();
-    scalarField& direction = tdirection.ref();
-
-    // Grab reference to line search
-    autoPtr<lineSearch>& lineSrch = optType_->getLineSearch();
-
-    // Store starting point
-    optType_->storeDesignVariables();
-
-    // Compute merit function before update
-    scalar meritFunction = optType_->computeMeritFunction();
-    lineSrch->setOldMeritValue(meritFunction);
-
-    // Get merit function derivative
-    const scalar dirDerivative =
-        optType_->meritFunctionDirectionalDerivative();
-    lineSrch->setDeriv(dirDerivative);
-    lineSrch->setDirection(direction);
-
-    // Reset initial step.
-    // Might be interpolated from previous optimisation cycles
-    lineSrch->reset();
-
-    // Perform line search
-    for (label iter = 0; iter < lineSrch->maxIters(); ++iter)
-    {
-        Info<< "\n- - - - - - - - - - - - - - -"  << endl;
-        Info<< "Line search iteration "   << iter << endl;
-        Info<< "- - - - - - - - - - - - - - -\n"  << endl;
-
-        // Update design variables. Multiplication with line search step
-        // happens inside the update(direction) function
-        optType_->update(direction);
-
-        // Solve all primal equations
-        solvePrimalEquations();
-
-        // Compute and set new merit function
-        meritFunction = optType_->computeMeritFunction();
-        lineSrch->setNewMeritValue(meritFunction);
-
-        if (lineSrch->converged())
-        {
-            // If line search criteria have been met, proceed
-            Info<< "Line search converged in " << iter + 1
-                << " iterations." << endl;
-            scalarField scaledCorrection(lineSrch->step()*direction);
-            optType_->updateOldCorrection(scaledCorrection);
-            optType_->write();
-            lineSrch()++;
-            break;
-        }
-        else
-        {
-            // If maximum number of iteration has been reached, continue
-            if (iter == lineSrch->maxIters() - 1)
-            {
-                Info<< "Line search reached max. number of iterations.\n"
-                    << "Proceeding to the next optimisation cycle" << endl;
-                scalarField scaledCorrection(lineSrch->step()*direction);
-                optType_->updateOldCorrection(scaledCorrection);
-                optType_->write();
-                lineSrch()++;
-            }
-            // Reset to initial design variables and update step
-            else
-            {
-                optType_->resetDesignVariables();
-                lineSrch->updateStep();
-            }
-        }
-    }
-}
-
-
-void Foam::steadyOptimisation::fixedStepUpdate()
-{
-    // Update design variables
-    optType_->update();
-
-    // Solve primal equations
-    solvePrimalEquations();
-}
-
-
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 Foam::steadyOptimisation::steadyOptimisation(fvMesh& mesh)
 :
     optimisationManager(mesh)
 {
+    initialize();
     optType_.reset
     (
         incompressible::optimisationType::New
@@ -221,25 +132,4 @@ bool Foam::steadyOptimisation::update()
 }
 
 
-void Foam::steadyOptimisation::updateDesignVariables()
-{
-    // Update design variables using either a line-search scheme or
-    // a fixed-step update
-    if (optType_->getLineSearch())
-    {
-        lineSearchUpdate();
-    }
-    else
-    {
-        fixedStepUpdate();
-    }
-
-    // Reset adjoint sensitivities in all adjoint solver managers
-    for (adjointSolverManager& adjSolverManager : adjointSolverManagers_)
-    {
-        adjSolverManager.clearSensitivities();
-    }
-}
-
-
 // ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/steadyOptimisation/steadyOptimisation.H

@@ -114,10 +114,6 @@ public:
 
         //- Whether to update the design variables
         virtual bool update();
-
-        //- Do a line search to find a correction satisfying the step
-        //- convergence criteria
-        virtual void updateDesignVariables();
 };
 
 

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/unsteadyOptimisation/unsteadyOptimisation.C

@@ -0,0 +1,525 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "unsteadyOptimisation.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(unsteadyOptimisation, 0);
+    addToRunTimeSelectionTable
+    (
+        optimisationManager,
+        unsteadyOptimisation,
+        dictionary
+    );
+}
+
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+void Foam::unsteadyOptimisation::updateOptTypeSource()
+{
+    forAll(primalSolvers_, pI)
+    {
+        primalSolvers_[pI].updateOptTypeSource(optType_->sourcePtr());
+    }
+
+    forAll(adjointSolverManagers_, asmI)
+    {
+        PtrList<adjointSolver>& adjointSolvers =
+            adjointSolverManagers_[asmI].adjointSolvers();
+
+        forAll(adjointSolvers, aI)
+        {
+            adjointSolvers[aI].updateOptTypeSource(optType_->sourcePtr());
+        }
+    }
+}
+
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+
+void Foam::unsteadyOptimisation::resetTime()
+{
+    timeManip_.moveToPrimalStartTime();
+}
+
+
+void Foam::unsteadyOptimisation::moveDesignVariables()
+{
+    if (shouldUpdateDesignVariables_)
+    {
+        // Updated grid should be written at the primal end time, to coinside
+        // with the primal and adjoint solutions to be stored then.  The
+        // (unknown) time index is not important at this point, so it remains
+        // unchanged.
+        timeManip_.storeTime();
+        timeManip_.moveToAdjointStartTime(false, false);
+
+        // Update design variables
+        optType_->update();
+
+        // Restore time
+        timeManip_.restoreTime();
+    }
+}
+
+
+void Foam::unsteadyOptimisation::moveDesignVariables
+(
+    scalarField& direction
+)
+{
+    if (shouldUpdateDesignVariables_)
+    {
+        // Updated grid should be written at the primal end time, to coinside
+        // with the primal and adjoint solutions to be stored then.  The
+        // (unknown) time index is not important at this point, so it remains
+        // unchanged.
+        timeManip_.storeTime();
+        timeManip_.moveToAdjointStartTime(false, false);
+
+        // Update design variables
+        optType_->update(direction);
+
+        // Restore time
+        timeManip_.restoreTime();
+    }
+}
+
+
+Foam::label Foam::unsteadyOptimisation::nActivePrimalSolvers()
+{
+    const dictionary& primalSolversDict =
+        IOdictionary::subDict("primalSolvers");
+    const wordList& primalSolverNames = primalSolversDict.toc();
+    label n(0);
+    for (const word& name : primalSolverNames)
+    {
+        if (primalSolversDict.subDict(name).getOrDefault<bool>("active", true))
+        {
+            n++;
+        }
+    }
+    return n;
+}
+
+
+Foam::label Foam::unsteadyOptimisation::nActiveAdjointSolvers()
+{
+    const dictionary& adjointManagersDict =
+        IOdictionary::subDict("adjointManagers");
+    const wordList& adjointManagerNames = adjointManagersDict.toc();
+    label n(0);
+    for (const word& name : adjointManagerNames)
+    {
+        const dictionary& dict = adjointManagersDict.subDict(name);
+        n += adjointSolverManager::nActiveAdjointSolvers(dict);
+    }
+    return n;
+}
+
+
+void Foam::unsteadyOptimisation::initialize()
+{
+    mesh_.moving(false); // Note: not sure if needed
+    // Boolean defining if primal fields will be read from a custom time
+    // provided by the user.
+    Switch useCustomReadTime(true);
+    Switch shouldWriteObjective(true);
+    if (!localIOdictionary::empty())
+    {
+        // Possible scenarios for the solution of the primal/adjoint equations:
+        // (a) one wishes to continue with the next optimization cycle, or
+        // (b) has run the primal solver, has stored the flow fields
+        // time-series and now wants to run adjoint,
+        // (c) has already solved the adjoint equations and wants to integrate
+        // them again based on the same primal fields and without proceeding to
+        // the next optimization cycle, or
+        // (d) wants to continue with the primal solver only.
+        // For (a), nothing needs to be done here.
+        // For (b), in the previous execution of the code only the flow
+        // equations were integrated and, now, the adjoint equations are
+        // about to be solved. Hence, isAdjointActive under uniform is false
+        // and nActiveAdjointSolvers() > 0 and nActivePrimalSolvers() >= 0.
+        // nActivePrimalSolvers() is allowed to take positive values since the
+        // user may have stored the primal problem and now wants to run adjoint
+        // only (nActivePrimalSolvers() = 0) or wants to run adjoint and, then,
+        // continue with the optimization (nActivePrimalSolvers() > 0)
+        // For (c), isAdjointActive under uniform is true,
+        // nActiveAdjointSolvers() > 0 and nActivePrimalSolvers() = 0.
+        // For (d), isAdjointActive under uniform is false,
+        // nActiveAdjointSolvers() = 0 and nActivePrimalSolvers() > 0.
+        // iOptCycles_ does not need  to be checked for the following reason.
+        // Even if iOptCycles_ > 0 and the user wants to run the primal solver
+        // only, then if
+        // (i) the previous optimization cycle has just been completed case4 is
+        // not activated and the manager proceeds as if a new optimization
+        // cycle begins (a), whereas if
+        // (ii) the primal solver has already been used, primal fields must be
+        // initialized using the last available time-step
+
+        label nPrimalSolvers = nActivePrimalSolvers();
+        label nAdjointSolvers = nActiveAdjointSolvers();
+        // Check if adjoint solvers were active in the previous execution
+        Switch isAdjointActive =
+            localIOdictionary::get<Switch>("isAdjointActive");
+
+        Switch case2(!isAdjointActive && nAdjointSolvers > 0);
+        Switch case3
+        (
+            isAdjointActive  && nAdjointSolvers > 0 && nPrimalSolvers == 0
+        );
+        Switch case4
+        (
+            !isAdjointActive && nAdjointSolvers == 0 && nPrimalSolvers > 0
+        );
+        DebugInfo
+            << "case2 " << case2 << nl
+            << "case3 " << case3 << nl
+            << "case4 " << case4 << endl;
+        if (case2 || case3)
+        {
+            // Start time of the primal is this time - the old span
+            timeManip_.setStartTime
+            (
+                mesh_.time().value() - localIOdictionary::get<scalar>("span")
+            );
+            // Read startTimeIndex from dict
+            timeManip_.setStartTimeIndex
+                (localIOdictionary::get<label>("primalStartTimeIndex"));
+            // Don't update design variables and avoid writing objectives
+            // since we are running adjoint only
+            shouldUpdateDesignVariables_ = false;
+            shouldWriteObjective = false;
+            // Don't solve the primal equations in the first go, even if they
+            // are enabled
+            solveFirstPrimalEqns_ = false;
+        }
+        else if (case4)
+        {
+            // Don't update design variables since we are running primal only
+            shouldUpdateDesignVariables_ = false;
+            // Disable editing readTime of the primal fields
+            useCustomReadTime = false;
+        }
+        if (case3)
+        {
+            if (--iOptCycle_ < 0)
+            {
+                FatalErrorInFunction
+                    << "iOptCycle = " << iOptCycle_ << ". Code should enter "
+                    << "here only if both the primal and adjoint" << nl
+                    << "equations have already been integrated for the" << nl
+                    << "current optimization cycle and the user wants to" << nl
+                    << "run the adjoint solver again" << endl
+                    << exit(FatalError);
+            }
+        }
+    }
+    setSolvers(useCustomReadTime);
+    // Deactivate writting objective functions in case that the primal
+    // solution of the current optimization cycle has been stored and
+    // the adjoint problem is about to be solved
+    if (!shouldWriteObjective)
+    {
+        forAll(adjointSolverManagers_, amI)
+        {
+            adjointSolverManagers_[amI].setWrite(false);
+            adjointSolverManagers_[amI].setWriteOption(IOobject::NO_WRITE);
+        }
+    }
+    // Set averaging start time (if activated)
+    forAll(primalSolvers_, psI)
+    {
+        primalSolvers_[psI].getVariablesSet().
+            adjustAverageStartTime(timeManip_.startTime().value());
+    }
+
+//  if (debug)
+//  {
+        Info<< "startTime " << timeManip_.startTime() << nl
+            << "startTimeIndex " << timeManip_.startTimeIndex() << nl
+            << "primalEndTime " << timeManip_.primalEndTime() << nl
+            << "span " << timeManip_.span() << endl;
+//  }
+}
+
+
+void Foam::unsteadyOptimisation::setSolvers(Switch useCustomReadTime)
+{
+    // Read primal fields from the time prescribed in the optimisationDict,
+    // Time index is not updated, but this should not be a problem
+    dictionary& primalSolversDict =
+        IOdictionary::subDict("primalSolvers");
+    const wordList& primalSolverNames = primalSolversDict.toc();
+
+    // Construct primal solvers
+    primalSolvers_.setSize(primalSolverNames.size());
+    forAll(primalSolvers_, solveri)
+    {
+        dictionary& solverDict =
+            primalSolversDict.subDict(primalSolverNames[solveri]);
+        if (primalSolvers_.size() > 1)
+        {
+            solverDict.add<bool>("useSolverNameForFields", true);
+        }
+        primalSolvers_.set
+        (
+            solveri,
+            primalSolver::New
+            (
+                mesh_,
+                managerType_,
+                solverDict,
+                useCustomReadTime
+            )
+        );
+    }
+
+    // Construct adjointSolverManagers
+    const dictionary& adjointManagersDict =
+        IOdictionary::subDict("adjointManagers");
+    const wordList& adjointManagerNames = adjointManagersDict.toc();
+    adjointSolverManagers_.setSize(adjointManagerNames.size());
+
+    label nAdjointSolvers(0);
+    label nActiveAdjointSolvers(0);
+    bool overrideUseSolverName(adjointSolverManagers_.size() > 1);
+    forAll(adjointSolverManagers_, manageri)
+    {
+        adjointSolverManagers_.set
+        (
+            manageri,
+            new adjointSolverManager
+            (
+                mesh_,
+                managerType_,
+                adjointManagersDict.subDict(adjointManagerNames[manageri]),
+                overrideUseSolverName
+            )
+        );
+        nAdjointSolvers +=
+            adjointSolverManagers_[manageri].nAdjointSolvers();
+        nActiveAdjointSolvers +=
+            adjointSolverManagers_[manageri].nActiveAdjointSolvers();
+    }
+    isAdjointActive_ = (nActiveAdjointSolvers > 0);
+
+    // Sanity checks on the naming convention
+    if (primalSolvers_.size() > 1)
+    {
+        for (const primalSolver& solveri : primalSolvers_)
+        {
+            if (!solveri.useSolverNameForFields())
+            {
+                FatalErrorInFunction
+                    << "Multiple primal solvers are present but "
+                    << "useSolverNameForFields is set to false in "
+                    << "primal solver " << solveri.solverName() << nl
+                    << "This is considered fatal."
+                    << exit(FatalError);
+            }
+        }
+    }
+
+    if (nAdjointSolvers > 1)
+    {
+        for (const adjointSolverManager& amI : adjointSolverManagers_)
+        {
+            const PtrList<adjointSolver>& adjointSolvers = amI.adjointSolvers();
+            for (const adjointSolver& asI : adjointSolvers)
+            {
+                if (!asI.useSolverNameForFields())
+                {
+                    FatalErrorInFunction
+                        << "Multiple adjoint solvers are present but "
+                        << "useSolverNameForFields is set to false in "
+                        << "adjoint solver " << asI.solverName() << nl
+                        << "This is considered fatal."
+                        << exit(FatalError);
+                }
+            }
+        }
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::unsteadyOptimisation::unsteadyOptimisation(fvMesh& mesh)
+:
+    optimisationManager(mesh),
+    localIOdictionary
+    (
+        IOobject
+        (
+            "optimisation",
+            mesh_.time().timeName(),
+            "uniform",
+            mesh_,
+            IOobject::READ_IF_PRESENT,
+            IOobject::AUTO_WRITE
+        ),
+        word::null
+    ),
+    iOptCycle_(localIOdictionary::getOrDefault<label>("optimisationCycle", 0)),
+    nOptCycles_(mesh_.time().controlDict().get<label>("nOptimisationCycles")),
+    isAdjointActive_(true),
+    timeManip_
+    (
+        const_cast<unsteadyTimeManipulation&>
+        (
+            unsteadyTimeManipulation::New(mesh)
+        )
+    ),
+    solveFirstPrimalEqns_(true)
+{
+    // Set primal and adjoint solvers
+    initialize();
+    optType_.reset
+    (
+        incompressible::optimisationType::New
+        (
+            mesh,
+            IOdictionary::subDict("optimisation"),
+            adjointSolverManagers_
+        )
+    );
+    // Update source ptrs in all solvers to look at the source held in optType
+    // Possible problem if mesh is adapted
+    updateOptTypeSource();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+Foam::optimisationManager& Foam::unsteadyOptimisation::operator++()
+{
+    iOptCycle_++;
+
+    if (!end())
+    {
+        Info<< "\n* * * * * * * * * * * * * * * * *" << endl;
+        Info<< "Optimisation cycle " << iOptCycle_ << endl;
+        Info<< "Time span ["
+            << time_.value() << ","
+            << time_.value() + timeManip_.span()
+            << "]" << endl;
+        Info<< "* * * * * * * * * * * * * * * * *\n" << endl;
+    }
+    timeManip_.newOptimisationCycle();
+
+    return *this;
+}
+
+
+Foam::optimisationManager& Foam::unsteadyOptimisation::operator++(int)
+{
+    return operator++();
+}
+
+
+bool Foam::unsteadyOptimisation::checkEndOfLoopAndUpdate()
+{
+    if (update())
+    {
+        optType_->update();
+    }
+    return end();
+}
+
+
+bool Foam::unsteadyOptimisation::end()
+{
+    return iOptCycle_ > nOptCycles_;
+}
+
+
+bool Foam::unsteadyOptimisation::update()
+{
+    return (iOptCycle_ != 1 && !end());
+}
+
+
+void Foam::unsteadyOptimisation::solvePrimalEquations()
+{
+    // Solve all primal equations
+    if (solveFirstPrimalEqns_)
+    {
+        optimisationManager::solvePrimalEquations();
+    }
+    solveFirstPrimalEqns_ = true;
+}
+
+
+void Foam::unsteadyOptimisation::solveAdjointEquations()
+{
+    optimisationManager::solveAdjointEquations();
+    // Re-activate Switch to update the design variables at the
+    // beggining of the next optimization cycle, if it has been
+    // deactivated
+    shouldUpdateDesignVariables_ = true;
+    // Allow writing objectives at the next optimization cycle,
+    // if deactivated
+    forAll(adjointSolverManagers_, amI)
+    {
+        adjointSolverManagers_[amI].setWrite(true);
+        adjointSolverManagers_[amI].setWriteOption(IOobject::AUTO_WRITE);
+    }
+}
+
+
+bool Foam::unsteadyOptimisation::writeData(Ostream& os) const
+{
+    DebugInfo
+        << "Calling unsteadyOptimisation::writeData" << endl;
+
+    // If adjoint hasn't been solved, don't treat this cycle as complete
+    label cycle(isAdjointActive_ ? iOptCycle_ : iOptCycle_ - 1);
+
+    const label startTimeIndex = timeManip_.startTimeIndex();
+    os.writeEntry("optimisationCycle", cycle);
+    os.writeEntry("isAdjointActive", isAdjointActive_);
+    os.writeEntry("primalStartTimeIndex", startTimeIndex);
+
+    DebugInfo
+        << "Writing data to localIOdictionary for continuation" << nl
+        << tab << "optimisationCycle    " << cycle              << nl
+        << tab << "isAdjointActive      " << isAdjointActive_   << nl
+        << tab << "primalStartTimeIndex " << startTimeIndex     << endl;
+
+    return true;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/unsteadyOptimisation/unsteadyOptimisation.H

@@ -0,0 +1,180 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::unsteadyOptimisation
+
+Description
+    Iterate the optimisation cycles. For steady state opt, this coinsides
+    with evolving Time
+
+SourceFiles
+    unsteadyOptimisation.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef unsteadyOptimisation_H
+#define unsteadyOptimisation_H
+
+#include "optimisationManager.H"
+#include "localIOdictionary.H"
+#include "unsteadyTimeManipulation.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                      Class unsteadyOptimisation Declaration
+\*---------------------------------------------------------------------------*/
+
+class unsteadyOptimisation
+:
+    public optimisationManager,
+    public localIOdictionary
+{
+private:
+
+    // Private Member Data
+
+        //- Current optimisation cycle
+        label iOptCycle_;
+
+        //- Number of optimisation cycles
+        label nOptCycles_;
+
+        //- Switch defining if at least one adjoint solver is active
+        Switch isAdjointActive_;
+
+        //- Time manipulation, common for all primal and adjoint solvers
+        unsteadyTimeManipulation& timeManip_;
+
+        //- Boolean to treat a special case
+        //  If adjoint was not solved in the previous code execution, but it is
+        //  solved now, together with the primal equations, avoid solving the
+        //  primal equations the first time
+        bool solveFirstPrimalEqns_;
+
+
+    // Private Member Functions
+
+        //- Update optimisationType source for all primal and adjoint solvers
+        void updateOptTypeSource();
+
+        //- Disallow default bitwise copy construct
+        unsteadyOptimisation(const unsteadyOptimisation&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const unsteadyOptimisation&) = delete;
+
+
+protected:
+
+    // Protected Member Functions
+
+        //- Reset time to primal time after a failed line search
+        virtual void resetTime() override;
+
+        virtual void moveDesignVariables() override;
+
+        virtual void moveDesignVariables
+        (
+            scalarField& direction
+        ) override;
+
+        //- Return number of active primal and adjoint solvers without
+        //- constructing any of the solvers.
+        //  It is calculated through reading dictionary entries. Warning: It is
+        //  designed to be used by initialize() function only. In this case no
+        //  mismatch can occur if the optimisationDict is changed during
+        //  runTime, since the primal or adjoint solvers are built directly
+        //  after calling this function. If the number of active adjoint
+        //  solvers is required elsewhere, use the nActiveAdjointSolvers()
+        //  function of each adjointSolverManager.
+        label nActivePrimalSolvers();
+
+        label nActiveAdjointSolvers();
+
+        virtual void initialize() override;
+
+        void setSolvers(Switch editPrimalReadTime);
+
+public:
+
+    //- Runtime type information
+    TypeName("unsteadyOptimisation");
+
+
+    // Constructors
+
+        //- Construct from components
+        unsteadyOptimisation(fvMesh& mesh);
+
+
+    // Destructor
+    virtual ~unsteadyOptimisation() = default;
+
+
+    // Member Functions
+
+        //- Prefix increment
+        virtual optimisationManager& operator++();
+
+        //- Postfix increment, this is identical to the prefix increment
+        virtual optimisationManager& operator++(int);
+
+        //- Return true if end of optimisation run
+        //  Also, updates the design variables if needed
+        virtual bool checkEndOfLoopAndUpdate();
+
+        //- Return true if end of optimisation run
+        virtual bool end();
+
+        //- Whether to update the design variables
+        virtual bool update();
+
+        //- Solve all primal equations
+        virtual void solvePrimalEquations() override;
+
+        //- Solve all adjoint equations
+        virtual void solveAdjointEquations() override;
+
+        //- write necessary data for continuation
+        virtual bool writeData(Ostream&) const override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/unsteadyOptimisation/unsteadyTimeManipulation/unsteadyTimeManipulation.C

@@ -0,0 +1,202 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2022 PCOpt/NTUA
+    Copyright (C) 2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "error.H"
+#include "unsteadyTimeManipulation.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(unsteadyTimeManipulation, 0);
+}
+
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::unsteadyTimeManipulation::printOut(const char* functionName)
+{
+    if (debug)
+    {
+        Info<< "After call to " << functionName << endl;
+        OSstream& os = Info.stream();
+        os.beginBlock();
+        os<< *this;
+        os.endBlock();
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::unsteadyTimeManipulation::unsteadyTimeManipulation
+(
+    const fvMesh& mesh
+)
+:
+    MeshObject<fvMesh, UpdateableMeshObject, unsteadyTimeManipulation>(mesh),
+    time_(const_cast<Time&>(mesh.time())),
+    startTime_(time_.startTime()),
+    startTimeIndex_(time_.startTimeIndex()),
+    endTimeIndex_(-1),
+    span_(time_.endTime().value() - time_.startTime().value()),
+    storedTime_(nullptr),
+    storedTimeIndex_(nullptr),
+    storedEndTime_(nullptr)
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::unsteadyTimeManipulation::moveToPrimalStartTime(bool setEndTime)
+{
+    time_.setTime(startTime_, startTimeIndex_);
+    if (setEndTime)
+    {
+        time_.setEndTime(startTime_.value() + span_);
+    }
+    printOut(FUNCTION_NAME);
+}
+
+
+void Foam::unsteadyTimeManipulation::moveToAdjointStartTime
+(
+    bool setEndTime,
+    bool setTimeIndex
+)
+{
+    label index(setTimeIndex ? endTimeIndex_ : time_.timeIndex());
+    time_.setTime(startTime_.value() + span_, index);
+    if (setEndTime)
+    {
+        // Set endTime of the adjoint solver as the start of the primal one,
+        // plus a deltaT
+        time_.setEndTime(startTime_.value() + time_.deltaT().value());
+    }
+    printOut(FUNCTION_NAME);
+}
+
+
+void Foam::unsteadyTimeManipulation::newOptimisationCycle()
+{
+    // Increment endTime by a time span
+    time_.setEndTime(time_.value() + span_);
+
+    // Adjust startTime of each optimisation loop
+    startTime_ = time_;
+    startTimeIndex_ = time_.timeIndex();
+    printOut(FUNCTION_NAME);
+}
+
+
+void Foam::unsteadyTimeManipulation::storeTime()
+{
+    storedTime_.reset(new dimensionedScalar(time_));
+    storedTimeIndex_.reset(new label(time_.timeIndex()));
+    storedEndTime_.reset(new dimensionedScalar(time_.endTime()));
+}
+
+
+void Foam::unsteadyTimeManipulation::restoreTime()
+{
+    if (storedTime_ && storedTimeIndex_)
+    {
+        time_.setTime(storedTime_(), storedTimeIndex_());
+        storedTime_.clear();
+        storedTimeIndex_.clear();
+    }
+    else
+    {
+        FatalErrorInFunction
+            << "Attempted to restore unset stored time and timeIndex"
+            << exit(FatalError)
+            << endl;
+    }
+
+    if (storedEndTime_)
+    {
+        time_.setEndTime(storedEndTime_());
+        storedEndTime_.clear();
+    }
+    else
+    {
+        FatalErrorInFunction
+            << "Attempted to restore unset stored endTime"
+            << exit(FatalError)
+            << endl;
+    }
+    printOut(FUNCTION_NAME);
+}
+
+
+void Foam::unsteadyTimeManipulation::writeEntries(Ostream& os) const
+{
+    os.beginBlock("localEntries");
+    os.writeEntry("startTime",  startTime());
+    os.writeEntry("startTimeIndex", startTimeIndex());
+    os.writeEntry("primalEndTime", primalEndTime());
+    os.writeEntry("endTimeIndex", endTimeIndex());
+    os.writeEntry("span", span_);
+    os.endBlock();
+
+    os.beginBlock("TimeEntries");
+    os.writeEntry("time", time_.value());
+    os.writeEntry("timeIndex", time_.timeIndex());
+    os.writeEntry("deltaT", time_.deltaT());
+    os.writeEntry("endTime", time_.endTime());
+    os.endBlock();
+}
+
+
+bool Foam::unsteadyTimeManipulation::movePoints()
+{
+    // Does nothing
+    return true;
+}
+
+
+void Foam::unsteadyTimeManipulation::updateMesh(const mapPolyMesh&)
+{
+    // Does nothing
+}
+
+
+// * * * * * * * * * * * * * * * Friend Operators  * * * * * * * * * * * * * //
+
+Foam::Ostream& Foam::operator<<
+(
+    Ostream& os,
+    const unsteadyTimeManipulation& timeManip
+)
+{
+    timeManip.writeEntries(os);
+    return os;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/optimisation/optimisationManager/unsteadyOptimisation/unsteadyTimeManipulation/unsteadyTimeManipulation.H

@@ -0,0 +1,247 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2022 PCOpt/NTUA
+    Copyright (C) 2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::unsteadyTimeManipulation
+
+Description
+    Class with helper functions to manipulate time during unsteady optimisation
+
+
+
+SourceFiles
+    unsteadyTimeManipulation.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef unsteadyTimeManipulation_H
+#define unsteadyTimeManipulation_H
+
+#include "MeshObject.H"
+#include "fvMesh.H"
+#include "OFstream.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// Forward Declarations
+class unsteadyTimeManipulation;
+Ostream& operator<< (Ostream&, const unsteadyTimeManipulation&);
+
+
+/*---------------------------------------------------------------------------*\
+                   Class unsteadyTimeManipulation Declaration
+\*---------------------------------------------------------------------------*/
+
+class unsteadyTimeManipulation
+:
+    public MeshObject<fvMesh, UpdateableMeshObject, unsteadyTimeManipulation>
+{
+protected:
+
+
+    // Protected data
+
+        //- Not constant reference to Time
+        Time& time_;
+
+        //- Start time of the optimisation loop
+        //  Will be updated at the beginning of each new loop
+        dimensionedScalar startTime_;
+
+        //- Start time index of the optimisation loop
+        label startTimeIndex_;
+
+        //- Start time index of the optimisation loop
+        label endTimeIndex_;
+
+        //- Span of the optimisation loop
+        scalar span_;
+
+
+        // Temporarily stored time features
+
+            autoPtr<dimensionedScalar> storedTime_;
+            autoPtr<label> storedTimeIndex_;
+            autoPtr<dimensionedScalar> storedEndTime_;
+
+
+    // Protected Member Functions
+
+        //- Print entries for debugging
+        void printOut(const char* functionName);
+
+
+private:
+
+    // Private Member Functions
+
+        //- No copy construct
+        unsteadyTimeManipulation(const unsteadyTimeManipulation&) = delete;
+
+        //- No copy assignment
+        void operator=(const unsteadyTimeManipulation&) = delete;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("unsteadyTimeManipulation");
+
+
+    // Constructors
+
+        //- Construct from components
+        unsteadyTimeManipulation(const fvMesh& mesh);
+
+
+    //- Destructor
+    virtual ~unsteadyTimeManipulation() = default;
+
+
+    // Member Functions
+
+        // Access
+
+            //- Return start time of the optimisation loop
+            inline const dimensionedScalar& startTime() const
+            {
+                return startTime_;
+            }
+
+            //- Return start time of the optimisation loop
+            inline label startTimeIndex() const
+            {
+                return startTimeIndex_;
+            }
+
+            //- Return span of the optimisation loop
+            inline label endTimeIndex() const
+            {
+                return endTimeIndex_;
+            }
+
+            //- Return span of the optimisation loop
+            inline scalar span() const
+            {
+                return span_;
+            }
+
+            //- Return end time of primal
+            inline scalar primalEndTime() const
+            {
+                return startTime_.value() + span_;
+            }
+
+
+        // Edit
+
+            //- Set startTime
+            inline void setStartTime(const scalar startTime)
+            {
+                startTime_.value() = startTime;
+            }
+
+            //- Set startTimeIndex
+            inline void setStartTimeIndex(const label startTimeIndex)
+            {
+                startTimeIndex_ = startTimeIndex;
+            }
+
+            //- Set span
+            inline void setSpan(const scalar span)
+            {
+                span_ = span;
+            }
+
+            //- Set endTimeIndex
+            inline void setEndTimeIndex(const label endTimeIndex)
+            {
+                endTimeIndex_ = endTimeIndex;
+            }
+
+
+            //- Store current endTimeIndex to local copy
+            inline void storeEndTimeIndex()
+            {
+                endTimeIndex_ = time_.timeIndex();
+            }
+
+            //- Move time to the beginning of the primal
+            //  Optionally sets endTime equal to startTime + span
+            void moveToPrimalStartTime(bool setEndTime = true);
+
+            //- Move time to the end of the primal
+            //  Optionally sets endTime equal to startTime
+            void moveToAdjointStartTime
+            (
+                bool setEndTime = true,
+                bool setTimeIndex = true
+            );
+
+            //- Increment time features at the beginning of each optimisation
+            //- cycle
+            void newOptimisationCycle();
+
+
+        //- Store current time features
+        void storeTime();
+
+        //- Retrieve last stored time features
+        void restoreTime();
+
+        //- Write local entries and time entries to stream
+        void writeEntries(Ostream& os) const;
+
+        //- Dummy function required by MeshObject.
+        virtual bool movePoints();
+
+        //- Dummy function required by MeshObject.
+        virtual void updateMesh(const mapPolyMesh&);
+
+
+    // Ostream operators
+
+        friend Ostream& operator<<
+        (
+            Ostream&,
+            const unsteadyTimeManipulation&
+        );
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolverManager/adjointSolverManager.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -27,6 +27,7 @@ License
 
 \*---------------------------------------------------------------------------*/
 
+#include "Ostream.H"
 #include "adjointSolverManager.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
@@ -36,6 +37,27 @@ namespace Foam
     defineTypeNameAndDebug(adjointSolverManager, 0);
 }
 
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::adjointSolverManager::checkIntegrationTimes() const
+{
+    forAll(adjointSolvers_, i)
+    {
+        const objectiveManager& objManager =
+            adjointSolvers_[i].getObjectiveManager();
+        if (!objManager.hasIntegrationTimes())
+        {
+            FatalErrorInFunction
+                << "The integration window of at least one of the objectives "
+                << "of adjointSolver '"<< adjointSolvers_[i].solverName()
+                << "' is undefined." << endl
+//              << "Either define the integration window "
+//              << "for all objectives or use FFT to one of them."
+                << exit(FatalError);
+        }
+    }
+}
+
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
@@ -62,6 +84,7 @@ Foam::adjointSolverManager::adjointSolverManager
     mesh_(mesh),
     dict_(dict),
     managerName_(dict.dictName()),
+    managerType_(managerType),
     primalSolverName_(dict.get<word>("primalSolver")),
     adjointSolvers_(0),
     objectiveSolverIDs_(0),
@@ -69,7 +92,8 @@ Foam::adjointSolverManager::adjointSolverManager
     operatingPointWeight_
     (
         dict.getOrDefault<scalar>("operatingPointWeight", 1)
-    )
+    ),
+    nActiveAdjointSolvers_(0)
 {
     dictionary& adjointSolversDict =
         const_cast<dictionary&>(dict.subDict("adjointSolvers"));
@@ -99,7 +123,10 @@ Foam::adjointSolverManager::adjointSolverManager
                 primalSolverName_
             )
         );
-
+        if (adjointSolvers_[namei].active())
+        {
+            nActiveAdjointSolvers_++;
+        }
         if (adjointSolvers_[namei].isConstraint())
         {
             constraintSolverIDs_[nConstraints++] = namei;
@@ -115,6 +142,9 @@ Foam::adjointSolverManager::adjointSolverManager
     Info<< "Found " << nConstraints
         << " adjoint solvers acting as constraints" << endl;
 
+    Info<< "Found " << nActiveAdjointSolvers_
+        << " active adjoint solvers" << endl;
+
     // Having more than one non-aggregated objectives per operating point
     // is needlessly expensive. Issue a warning
     if (objectiveSolverIDs_.size() > 1)
@@ -122,8 +152,9 @@ Foam::adjointSolverManager::adjointSolverManager
         WarningInFunction
             << "Number of adjoint solvers corresponding to objectives "
             << "is greater than 1 (" << objectiveSolverIDs_.size() << ")" << nl
-            << "Consider aggregating your objectives to one" << endl;
+            << "Consider aggregating your objectives to one" << nl << endl;
     }
+    checkIntegrationTimes();
 }
 
 
@@ -163,6 +194,24 @@ const Foam::dictionary& Foam::adjointSolverManager::dict() const
 }
 
 
+void Foam::adjointSolverManager::setWrite(const bool shouldWrite)
+{
+    forAll(adjointSolvers_, i)
+    {
+        adjointSolvers_[i].getObjectiveManager().setWrite(shouldWrite);
+    }
+}
+
+
+void Foam::adjointSolverManager::setWriteOption(IOobject::writeOption w)
+{
+    forAll(adjointSolvers_, i)
+    {
+        adjointSolvers_[i].getObjectiveManager().setWriteOption(w);
+    }
+}
+
+
 const Foam::PtrList<Foam::adjointSolver>&
 Foam::adjointSolverManager::adjointSolvers() const
 {
@@ -177,12 +226,51 @@ Foam::adjointSolverManager::adjointSolvers()
 }
 
 
+Foam::wordList Foam::adjointSolverManager::adjointSolversNames() const
+{
+    wordList names(adjointSolvers_.size());
+    forAll(adjointSolvers_, sI)
+    {
+        names[sI]  = adjointSolvers_[sI].name();
+    }
+    return names;
+}
+
+
 Foam::scalar Foam::adjointSolverManager::operatingPointWeight() const
 {
     return operatingPointWeight_;
 }
 
 
+Foam::label Foam::adjointSolverManager::nActiveAdjointSolvers() const
+{
+    return nActiveAdjointSolvers_;
+}
+
+
+Foam::label Foam::adjointSolverManager::nActiveAdjointSolvers
+(
+    const dictionary& dict
+)
+{
+    const dictionary& adjointSolversDict = dict.subDict("adjointSolvers");
+    const wordList adjSolverNames = adjointSolversDict.toc();
+    label n(0);
+    Switch active(true);
+    forAll(adjSolverNames, namei)
+    {
+        active = adjointSolversDict.subDict(adjSolverNames[namei]).
+            getOrDefault<bool>("active", true);
+        if (active)
+        {
+            n++;
+        }
+    }
+    return n;
+}
+
+
 Foam::label Foam::adjointSolverManager::nConstraints() const
 {
     return constraintSolverIDs_.size();
@@ -316,4 +404,13 @@ void Foam::adjointSolverManager::updatePrimalBasedQuantities(const word& name)
 }
 
 
+void Foam::adjointSolverManager::postLineSearch()
+{
+    for (adjointSolver& solver : adjointSolvers_)
+    {
+        solver.postLineSearch();
+    }
+}
+
+
 // ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolverManager/adjointSolverManager.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -77,6 +77,8 @@ protected:
 
         const word managerName_;
 
+        const word managerType_;
+
         const word primalSolverName_;
 
         PtrList<adjointSolver> adjointSolvers_;
@@ -87,6 +89,13 @@ protected:
 
         scalar operatingPointWeight_;
 
+        label nActiveAdjointSolvers_;
+
+
+    // Protected Member Functions
+
+        //- Check integration times for unsteady runs
+        void checkIntegrationTimes() const;
 
 public:
 
@@ -125,15 +134,33 @@ public:
             //- Const access to the construction dictionary
             const dictionary& dict() const;
 
+            //- Should the objectives be written to file upon calling the
+            //  corresponding write() function?
+            void setWrite(const bool shouldWrite);
+
+            //- Should the localIOdictionary be written?
+            void setWriteOption(IOobject::writeOption w);
+
             //- Const access to adjoint solvers
             const PtrList<adjointSolver>& adjointSolvers() const;
 
             //- Non-const access to adjoint solvers
             PtrList<adjointSolver>& adjointSolvers();
 
+            //- Return the names of all adjointSolvers
+            wordList adjointSolversNames() const;
+
             //- Const access to adjoint solvers
             scalar operatingPointWeight() const;
 
+            //- Return number of active adjoint solvers, either corresponding
+            //  to objectives or constraints
+            label nActiveAdjointSolvers() const;
+
+            //- Static function returning the number of active adjoint
+            //  solvers reading dict
+            static label nActiveAdjointSolvers(const dictionary& dict);
+
             //- Number of adjoint solvers corresponding to constraints
             label nConstraints() const;
 
@@ -173,6 +200,9 @@ public:
             //  For instance, primal fields of adjoint turbulence models
             void updatePrimalBasedQuantities(const word& name);
 
+            //- Actions to be executed after the convergence of lineSearch
+            void postLineSearch();
+
 
         // IO
 

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolvers/incompressible/adjointPimple/adjointPimple.C

@@ -0,0 +1,588 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "pimple.H"
+#include "adjointPimple.H"
+#include "findRefCell.H"
+#include "constrainHbyA.H"
+#include "constrainPressure.H"
+#include "adjustPhi.H"
+#include "fvOptions.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(adjointPimple, 0);
+    addToRunTimeSelectionTable
+    (
+        incompressibleAdjointSolver,
+        adjointPimple,
+        dictionary
+    );
+}
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+Foam::incompressibleAdjointVars& Foam::adjointPimple::allocateVars()
+{
+    vars_.reset
+    (
+        new incompressibleAdjointVars
+        (
+            mesh_,
+            solverControl_(),
+            objectiveManagerPtr_(),
+            primalVars_
+        )
+    );
+    return getAdjointVars();
+}
+
+
+void Foam::adjointPimple::setDeltaT()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/general/include/setDeltaT.H
+    if (!deltaTList_.empty())
+    {
+        Time& runTime = const_cast<Time&>(mesh_.time());
+        DebugInfo
+            << "runTime.timeIndex(), primalStartTimeIndex = "
+            << runTime.timeIndex() << " " << timeManip_.startTimeIndex()
+            << endl;
+        runTime.setDeltaT
+        (
+            deltaTList_[runTime.timeIndex() - timeManip_.startTimeIndex() -1]
+        );
+
+        Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
+    }
+
+}
+
+
+void Foam::adjointPimple::setTime()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    --time;
+}
+
+
+void Foam::adjointPimple::CourantNo() const
+{
+    const surfaceScalarField& phi = primalVars_.phiInst();
+    const Time& runTime = mesh_.time();
+    const fvMesh& mesh = mesh_;
+    #include "CourantNo.H"
+}
+
+
+void Foam::adjointPimple::continuityErrors()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/incompressible/continuityErrs.H
+    const Time& runTime = mesh_.time();
+    const fvMesh& mesh = mesh_;
+    const surfaceScalarField& phi = adjointVars_.phiaInst();
+    scalar& cumulativeContErr = cumulativeContErr_;
+    #include "continuityErrs.H"
+}
+
+
+void Foam::adjointPimple::accumulateSensitivities()
+{
+    if (computeSensitivities_)
+    {
+        adjointSensitivity_->accumulateIntegrand(mesh_.time().deltaTValue());
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::adjointPimple::adjointPimple
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const dictionary& dict,
+    const word& primalSolverName
+)
+:
+    incompressibleAdjointSolver
+    (
+        mesh,
+        managerType,
+        dict,
+        primalSolverName
+    ),
+    solverControl_(PIMPLEControl::New(mesh, managerType, *this)),
+    adjointVars_(allocateVars()),
+    cumulativeContErr_(Zero),
+    adjointSensitivity_(nullptr),
+    primalStorage_(getPrimalSolver().getPrimalStorage()),
+    deltaTList_(refCast<pimple>(getPrimalSolver()).getDeltaTList()),
+    timeManip_
+    (
+        const_cast<unsteadyTimeManipulation&>
+        (
+            unsteadyTimeManipulation::New(mesh)
+        )
+    )
+{
+    ATCModel_.reset
+    (
+        ATCModel::New
+        (
+            mesh,
+            primalVars_,
+            adjointVars_,
+            dict.subDict("ATCModel")
+        ).ptr()
+    );
+
+    addExtraSchemes();
+    setRefCell
+    (
+        adjointVars_.paInst(),
+        solverControl_().dict(),
+        solverControl_().pRefCell(),
+        solverControl_().pRefValue()
+    );
+
+    if (computeSensitivities_)
+    {
+        const IOdictionary& optDict =
+            mesh.lookupObject<IOdictionary>("optimisationDict");
+
+        adjointSensitivity_.reset
+        (
+            incompressible::adjointSensitivity::New
+            (
+                mesh,
+                optDict.subDict("optimisation").subDict("sensitivities"),
+                *this
+            ).ptr()
+        );
+    }
+
+    // Check integration times of the objectives
+    objectiveManagerPtr_().checkIntegrationTimes();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+bool Foam::adjointPimple::readDict(const dictionary& dict)
+{
+    if (incompressibleAdjointSolver::readDict(dict))
+    {
+        if (adjointSensitivity_.valid())
+        {
+            const IOdictionary& optDict =
+                mesh_.lookupObject<IOdictionary>("optimisationDict");
+
+            adjointSensitivity_().readDict
+            (
+                optDict.subDict("optimisation").subDict("sensitivities")
+            );
+        }
+
+        return true;
+    }
+
+    return false;
+}
+
+
+void Foam::adjointPimple::solveIter()
+{
+    CourantNo();
+    setDeltaT();
+    setTime();
+
+    // Retrieve primal fields of the time step. Retrieving of the first
+    // time-step of the adjoint loop is also necessary if more than one adjoint
+    // solvers are used. Includes potential recomputation of the primal fields,
+    // depending on the primal storage strategy
+    primalStorage_->retrieveVariables();
+    const Time& time = mesh_.time();
+    Info<< "Time = " << time.timeName() << "\n" << endl;
+
+    // Update objective related fields
+    objectiveManagerPtr_->updateOrNullify();
+
+    // Update turbulence model and ATC related terms
+    incompressibleAdjointSolver::updatePrimalBasedQuantities();
+
+    // Grab primal references
+    const surfaceScalarField& phi = primalVars_.phi();
+    // Grab adjoint references
+    volScalarField& pa = adjointVars_.paInst();
+    volVectorField& Ua = adjointVars_.UaInst();
+    surfaceScalarField& phia = adjointVars_.phiaInst();
+    autoPtr<incompressibleAdjoint::adjointRASModel>& adjointTurbulence =
+        adjointVars_.adjointTurbulence();
+    const label&  paRefCell  = solverControl_().pRefCell();
+    const scalar& paRefValue = solverControl_().pRefValue();
+    fv::options& fvOptions(fv::options::New(this->mesh_));
+
+    while (solverControl_().loop())
+    {
+        // Momentum predictor
+        //~~~~~~~~~~~~~~~~~~~
+
+        tmp<fvVectorMatrix> tUaEqn
+        (
+            fvm::ddt(Ua) + fvm::div(-phi, Ua)
+          + adjointTurbulence->divDevReff(Ua)
+          + adjointTurbulence->adjointMeanFlowSource()
+          ==
+            fvOptions(Ua)
+        );
+        fvVectorMatrix& UaEqn = tUaEqn.ref();
+
+        // Add sources from boundary conditions
+        UaEqn.boundaryManipulate(Ua.boundaryFieldRef());
+
+        // Add sources from volume-based objectives
+        objectiveManagerPtr_().addUaEqnSource(UaEqn);
+
+        // Add ATC term
+        ATCModel_->addATC(UaEqn);
+
+        UaEqn.relax();
+
+        fvOptions.constrain(UaEqn);
+
+        if (solverControl_().momentumPredictor())
+        {
+            Foam::solve(UaEqn == -fvc::grad(pa));
+
+            fvOptions.correct(Ua);
+        }
+
+        // Pressure Eq
+        //~~~~~~~~~~~~
+        while (solverControl_().correct())
+        {
+            volScalarField rAUa(1.0/UaEqn.A());
+            volVectorField HabyA(constrainHbyA(rAUa*UaEqn.H(), Ua, pa));
+            surfaceScalarField phiaHbyA
+            (
+                "phiaHbyA",
+                fvc::flux(HabyA)
+              //+ MRF_.zeroFilter(fvc::interpolate(rAU)*fvc::ddtCorr(U, phi))
+            );
+
+            if (pa.needReference())
+            {
+                fvc::makeRelative(phiaHbyA, Ua);
+                adjustPhi(phiaHbyA, Ua, pa);
+                fvc::makeAbsolute(phiaHbyA, Ua);
+            }
+
+            tmp<volScalarField> rAtUa(rAUa);
+
+            if (solverControl_().consistent())
+            {
+                rAtUa = 1.0/max(1.0/rAUa - UaEqn.H1(), 0.1/rAUa);
+                phiaHbyA +=
+                    fvc::interpolate(rAtUa() - rAUa)*fvc::snGrad(pa)*mesh_.magSf();
+                HabyA -= (rAUa - rAtUa())*fvc::grad(pa);
+            }
+
+            if (solverControl_().nCorrPISO() <= 1)
+            {
+                tUaEqn.clear();
+            }
+
+            // Non-orthogonal pressure corrector loop
+            while (solverControl_().correctNonOrthogonal())
+            {
+                fvScalarMatrix paEqn
+                (
+                    fvm::laplacian(rAtUa(), pa) == fvc::div(phiaHbyA)
+                );
+
+                paEqn.boundaryManipulate(pa.boundaryFieldRef());
+
+                fvOptions.constrain(paEqn);
+                paEqn.setReference(paRefCell, paRefValue);
+
+                paEqn.solve
+                (
+                    mesh_.solver(pa.select(solverControl_().finalInnerIter()))
+                );
+
+                if (solverControl_().finalNonOrthogonalIter())
+                {
+                    phia = phiaHbyA - paEqn.flux();
+                }
+            }
+
+            continuityErrors();
+
+            // Explicitly relax pressure for momentum corrector
+            pa.relax();
+
+            Ua = HabyA - rAtUa()*fvc::grad(pa);
+            Ua.correctBoundaryConditions();
+            fvOptions.correct(Ua);
+            pa.correctBoundaryConditions();
+        }
+
+        if (solverControl_().turbCorr())
+        {
+            adjointTurbulence->correct();
+        }
+
+        if (solverControl_().printMaxMags())
+        {
+            dimensionedScalar maxUa = max(mag(Ua)());
+            dimensionedScalar maxpa = max(mag(pa)());
+            Info<< "Max mag of adjoint velocity = " << maxUa.value() << endl;
+            Info<< "Max mag of adjoint pressure = " << maxpa.value() << endl;
+        }
+    }
+
+    // Average fields if necessary
+    adjointVars_.computeMeanUnsteadyFields(timeManip_.primalEndTime());
+
+    // Calls time.write()
+    solverControl_().writeFields();
+
+    // Print execution time
+    time.printExecutionTime(Info);
+}
+
+
+void Foam::adjointPimple::solve()
+{
+    // Iterate
+    if (active_)
+    {
+        preLoop();
+        while (loop())
+        {
+            solveIter();
+            accumulateSensitivities();
+        }
+        postLoop();
+    }
+}
+
+
+bool Foam::adjointPimple::run()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    return time.reverseRun();
+}
+
+
+bool Foam::adjointPimple::loop()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    // mesh_.time().reverseRun() is actually needed here. Not a mistake.
+    // Chosen for compatibility reasons with the piso algorithm
+    // and the 'solveWithArgs' function at solverTemplates.C
+    return time.reverseRun();
+}
+
+
+void Foam::adjointPimple::preLoop()
+{
+    // Disable re-writting of primal fields
+    primalVars_.setWriteOption(IOobject::NO_WRITE);
+
+    // Reset time to the beginning of the adjoint loop.
+    // Resets endTime too
+    timeManip_.moveToAdjointStartTime();
+
+    //  TODO: To be able to stop the adjoint solution midway and continue
+    //  thereafter, the oldTimes of the adjoint fields are required to be
+    //  correctly read.  Make sure that these are not reset due to change in
+    //  time, upon calling oldTime() function.
+
+    //  Reset all adjoint fields to zero
+    adjointVars_.nullify();
+    adjointVars_.resetMeanFields();
+
+    // Copy pointers to storage instances and possibly read compressed fields
+    // in cases of restarted runs
+    primalStorage_->preAdjointLoop();
+
+    // The adjoint equations should be also solved at the last primal time-step.
+    // Advance time once more to get to the correct time during the solution
+    // of the first adjoint time-setp
+    const_cast<Time&>(mesh_.time())++;
+
+    // Print out
+    Info<< nl << "- - - - - - - - - - - - - - - - - - - - -" << endl;
+    Info<< "Solving adjoint equations for solver " << solverName() << endl;
+    Info<< "- - - - - - - - - - - - - - - - - - - - -" << nl << endl;
+}
+
+
+void Foam::adjointPimple::postLoop()
+{
+    // rite adjoint fields at primalEndTime. Although the adjoint equations
+    // are integrated backwards in time starting from primalEndTime and ending
+    // at primalStartTime, the appropriate time to write the adjoint fields is
+    // the primalEndTime. This is not only to have both the primal and adjoint
+    // fields of each optimization cycle written at the same time, but more
+    // importantly to have consistency between the written grid and the adjoint
+    // fields. To do so, reset only the time value to that corresponding to the
+    // end of the primal. Keep the timeIndex unchanged, so that
+    // GeometricField::storeOldTime() function is not called by the time
+    // GeometricField::oldTime() is called from the
+    // incompressibleAdjointVars::write() function. This way, the adjoint
+    // fields will be written correctly in disk without oldTimes to been
+    // shifted
+    Time& time = const_cast<Time&>(mesh_.time());
+    timeManip_.moveToAdjointStartTime(false, false);
+    if (!time.writeTime())
+    {
+        adjointVars_.write();
+    }
+    // Completely reset time to that corresponding to the end of the primal
+    // problem.
+    timeManip_.moveToAdjointStartTime();
+    // Write data except for the adjoint fields that have already been written
+    if (!time.writeTime())
+    {
+        adjointVars_.setWriteOption(IOobject::NO_WRITE);
+        time.writeNow();
+        this->writeNow();
+        adjointVars_.setWriteOption(IOobject::AUTO_WRITE);
+    }
+
+    // Print useful info and rewind storage pointers
+    primalStorage_->postAdjointLoop();
+
+    // Compute sensitivities
+    adjointSolver::postLoop();
+
+    //- Re-enable writting of primal fields
+    primalVars_.setWriteOption(IOobject::AUTO_WRITE);
+}
+
+
+void Foam::adjointPimple::postLineSearch()
+{
+    // Set integration times for the next optimisation cycle
+    objectiveManagerPtr_().incrementIntegrationTimes(timeManip_.span());
+}
+
+
+void Foam::adjointPimple::computeObjectiveSensitivities()
+{
+    if (computeSensitivities_)
+    {
+        const scalarField& sens = adjointSensitivity_->calculateSensitivities();
+        if (!sensitivities_)
+        {
+            sensitivities_.reset(new scalarField(sens.size(), scalar(0)));
+        }
+        sensitivities_.ref() = sens;
+    }
+    else
+    {
+        sensitivities_.reset(new scalarField(0));
+    }
+}
+
+
+const Foam::scalarField& Foam::adjointPimple::getObjectiveSensitivities()
+{
+    if (!sensitivities_.valid())
+    {
+        computeObjectiveSensitivities();
+    }
+
+    return sensitivities_();
+}
+
+
+void Foam::adjointPimple::clearSensitivities()
+{
+    if (computeSensitivities_)
+    {
+        adjointSensitivity_->clearSensitivities();
+        adjointSolver::clearSensitivities();
+    }
+}
+
+
+Foam::sensitivity& Foam::adjointPimple::getSensitivityBase()
+{
+    if (adjointSensitivity_.valid())
+    {
+        return adjointSensitivity_();
+    }
+    else
+    {
+        FatalErrorInFunction
+            << "Sensitivity object not allocated \n"
+            << "Turn computeSensitivities on in "
+            << solverName_
+            << nl << nl
+            << exit(FatalError);
+
+        return adjointSensitivity_();
+    }
+}
+
+
+void Foam::adjointPimple::updatePrimalBasedQuantities()
+{
+    // Update turbulence model and ATC related terms
+    incompressibleAdjointSolver::updatePrimalBasedQuantities();
+
+    // Write mean values for all objectives
+    PtrList<objective>& objectives
+        = objectiveManagerPtr_->getObjectiveFunctions();
+    for (objective& obj : objectives)
+    {
+        if (obj.shouldWrite())
+        {
+            obj.writeMeanValue();
+        }
+    }
+}
+
+
+bool Foam::adjointPimple::writeData(Ostream& os) const
+{
+    os.writeEntry("averageIter", solverControl_().averageIter());
+    return adjointSolver::writeData(os);
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolvers/incompressible/adjointPimple/adjointPimple.H

@@ -0,0 +1,218 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::adjointPimple
+
+Description
+    Solution of the incompressible, unsteady adjoint equations using the PIMPLE
+    algorithm
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef adjointPimple_H
+#define adjointPimple_H
+
+#include "incompressibleAdjointSolver.H"
+#include "PIMPLEControl.H"
+#include "incompressibleVars.H"
+#include "incompressibleAdjointVars.H"
+#include "adjointSensitivityIncompressible.H"
+#include "primalStorage.H"
+#include "unsteadyTimeManipulation.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                        Class adjointPimple Declaration
+\*---------------------------------------------------------------------------*/
+
+class adjointPimple
+:
+    public incompressibleAdjointSolver
+{
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        adjointPimple(const adjointPimple&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const adjointPimple&) = delete;
+
+
+protected:
+
+    // Protected data
+
+        //- Solver control
+        autoPtr<PIMPLEControl> solverControl_;
+
+        //- Reference to incompressibleAdjointVars
+        //  Used for convenience and to avoid repetitive dynamic_casts
+        //  Same as getAdjointVars()
+        incompressibleAdjointVars& adjointVars_;
+
+        //- Cumulative continuity error
+        scalar cumulativeContErr_;
+
+        //- Sensitivity Derivatives engine
+        autoPtr<incompressible::adjointSensitivity> adjointSensitivity_;
+
+        //- Reference to primal storage mechanism
+        autoPtr<primalStorage>& primalStorage_;
+
+        //- labelList containing all the time-step dependent pointers necessary
+        //  for the sucessfull retrieving of the variableSet
+        labelList storagePtrs_;
+
+        //- Time instances and indices at the beginning and end of each
+        //- optimisation loop
+        dimensionedScalar primalEndTime_;
+
+        //- Reference to the deltaTList of the primal solver
+        const DynamicList<scalar>& deltaTList_;
+
+        //- Time manipulation, common for all primal and adjoint solvers
+        unsteadyTimeManipulation& timeManip_;
+
+
+    // Protected Member Functions
+
+        //- Allocate incompressibleAdjointVars and return reference to be used
+        //- for convenience in the rest of the class.
+        incompressibleAdjointVars& allocateVars();
+
+        //- Reset time-step to maintain a constant maximum courant Number.
+        //  Reduction of time-step is immediate, but increase is damped to
+        //  avoid unstable oscillations.
+        void setDeltaT();
+
+        //- Decrease time
+        void setTime();
+
+        //- Compute Courant No
+        void CourantNo() const;
+
+        //- Compute continuity errors
+        void continuityErrors();
+
+        //- Accumulate sensitivities from the various time instances
+        void accumulateSensitivities();
+
+
+public:
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("adjointPimple");
+
+
+    // Constructors
+
+        //- Construct from mesh and dictionary
+        adjointPimple
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const dictionary& dict,
+            const word& primalSolverName
+        );
+
+
+    //- Destructor
+    virtual ~adjointPimple() = default;
+
+
+    // Member Functions
+
+        virtual bool readDict(const dictionary& dict);
+
+        // Evolution
+
+            //- Execute one iteration of the solution algorithm
+            virtual void solveIter();
+
+            //- Main control loop
+            virtual void solve();
+
+            //- Looper (advances iters, time step)
+            virtual bool run();
+
+            //- Looper (advances iters, time step)
+            virtual bool loop();
+
+            //- Functions to be called before loop
+            virtual void preLoop();
+
+            //- Functions to be called after loop
+            virtual void postLoop();
+
+            //- Functions to be called after the convergence of linearSearch
+            virtual void postLineSearch();
+
+            //- Compute sensitivities of the underlaying objectives
+            virtual void computeObjectiveSensitivities();
+
+            //- Grab a reference to the computed sensitivities
+            virtual const scalarField& getObjectiveSensitivities();
+
+            //- Clears the sensitivity field known by the adjoint solver
+            //- and zeros sensitivities constituents
+            virtual void clearSensitivities();
+
+            //- Return the base sensitivity object
+            virtual sensitivity& getSensitivityBase();
+
+            //- Update primal based quantities
+            //- related to the objective functions.
+            //  Also writes the objective function values to files.
+            //  Written here and not in the postLoop function of the primal
+            //  to make sure we don't pollute the objective files with
+            //  objectives of non-converged linearSearch iterations
+            virtual void updatePrimalBasedQuantities();
+
+            //- Write average iteration
+            virtual bool writeData(Ostream& os) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolvers/incompressible/adjointPiso/adjointPiso.C

@@ -0,0 +1,576 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "adjointPiso.H"
+#include "findRefCell.H"
+#include "constrainHbyA.H"
+#include "constrainPressure.H"
+#include "adjustPhi.H"
+#include "fvOptions.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(adjointPiso, 0);
+    addToRunTimeSelectionTable
+    (
+        incompressibleAdjointSolver,
+        adjointPiso,
+        dictionary
+    );
+}
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::adjointPiso::printFields()
+{
+    if (debug > 1)
+    {
+        const word timeName = mesh_.time().timeName();
+        const word prefix = "after solving for t = " + timeName + " ";
+        volScalarField& pa = adjointVars_.paInst();
+        volVectorField& Ua = adjointVars_.UaInst();
+        surfaceScalarField& phia = adjointVars_.phiaInst();
+        Info<< "Debug: Ua.nOldTimes()   = " << Ua.nOldTimes() << endl;
+        Info<< "Debug: phia.nOldTimes() = " << phia.nOldTimes() << endl;
+        Info<< prefix << "pa:\n" << pa << endl;
+        Info<< prefix << "Ua:\n" << Ua << endl;
+        Info<< prefix << "Ua.oldTime():\n" << Ua.oldTime() << endl;
+        Info<< prefix << "phia:\n" << phia << endl;
+    }
+}
+
+
+void Foam::adjointPiso::printPrimalFields()
+{
+    if (debug > 2)
+    {
+        const word timeName = mesh_.time().timeName();
+        const word prefix = "primal fields for t = " + timeName + " ";
+        volScalarField& p = primalVars_.pInst();
+        volVectorField& U = primalVars_.UInst();
+        surfaceScalarField& phi = primalVars_.phiInst();
+        Info<< prefix << "p:\n"   << p   << endl;
+        Info<< prefix << "U:\n"   << U   << endl;
+        Info<< prefix << "phi:\n" << phi << endl;
+        incompressible::RASModelVariables& rasVars =
+            primalVars_.RASModelVariables()();
+        if (rasVars.hasTMVar1())
+        {
+            Info << prefix << " TMVar1:\n" << rasVars.TMVar1Inst() << endl;
+        }
+        if (rasVars.hasTMVar2())
+        {
+            Info << prefix << " TMVar2:\n" << rasVars.TMVar2Inst() << endl;
+        }
+        if (rasVars.hasNut())
+        {
+            Info << prefix << " nut:\n" << rasVars.nutRefInst() << endl;
+        }
+    }
+}
+
+
+Foam::incompressibleAdjointVars& Foam::adjointPiso::allocateVars()
+{
+    vars_.reset
+    (
+        new incompressibleAdjointVars
+        (
+            mesh_,
+            solverControl_(),
+            objectiveManagerPtr_(),
+            primalVars_
+        )
+    );
+    return getAdjointVars();
+}
+
+
+void Foam::adjointPiso::CourantNo() const
+{
+    const surfaceScalarField& phi = primalVars_.phiInst();
+    const Time& runTime = mesh_.time();
+    const fvMesh& mesh = mesh_;
+    #include "CourantNo.H"
+}
+
+
+void Foam::adjointPiso::continuityErrors()
+{
+    const surfaceScalarField& phia = adjointVars_.phiaInst();
+    volScalarField contErr(fvc::div(phia));
+
+    scalar sumLocalContErr = mesh_.time().deltaTValue()*
+        mag(contErr)().weightedAverage(mesh_.V()).value();
+
+    scalar globalContErr = mesh_.time().deltaTValue()*
+        contErr.weightedAverage(mesh_.V()).value();
+    cumulativeContErr_ += globalContErr;
+
+    Info<< "time step continuity errors : sum local = " << sumLocalContErr
+        << ", global = " << globalContErr
+        << ", cumulative = " << cumulativeContErr_
+        << endl;
+}
+
+
+void Foam::adjointPiso::accumulateSensitivities()
+{
+    if (computeSensitivities_)
+    {
+        adjointSensitivity_->accumulateIntegrand(mesh_.time().deltaTValue());
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::adjointPiso::adjointPiso
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const dictionary& dict,
+    const word& primalSolverName
+)
+:
+    incompressibleAdjointSolver
+    (
+        mesh,
+        managerType,
+        dict,
+        primalSolverName
+    ),
+    solverControl_(PISOControl::New(mesh, managerType, *this)),
+    adjointVars_(allocateVars()),
+    cumulativeContErr_(Zero),
+    adjointSensitivity_(nullptr),
+    primalStorage_(getPrimalSolver().getPrimalStorage()),
+    timeManip_
+    (
+        const_cast<unsteadyTimeManipulation&>
+        (
+            unsteadyTimeManipulation::New(mesh)
+        )
+    )
+{
+    ATCModel_.reset
+    (
+        ATCModel::New
+        (
+            mesh,
+            primalVars_,
+            adjointVars_,
+            dict.subDict("ATCModel")
+        ).ptr()
+    );
+
+    addExtraSchemes();
+    setRefCell
+    (
+        adjointVars_.paInst(),
+        solverControl_().dict(),
+        solverControl_().pRefCell(),
+        solverControl_().pRefValue()
+    );
+
+    if (computeSensitivities_)
+    {
+        const IOdictionary& optDict =
+            mesh.lookupObject<IOdictionary>("optimisationDict");
+
+        adjointSensitivity_.reset
+        (
+            incompressible::adjointSensitivity::New
+            (
+                mesh,
+                optDict.subDict("optimisation").subDict("sensitivities"),
+                *this
+            ).ptr()
+        );
+    }
+
+    // Check integration times of the objectives
+    objectiveManagerPtr_().checkIntegrationTimes();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+bool Foam::adjointPiso::readDict(const dictionary& dict)
+{
+    if (incompressibleAdjointSolver::readDict(dict))
+    {
+        if (adjointSensitivity_.valid())
+        {
+            const IOdictionary& optDict =
+                mesh_.lookupObject<IOdictionary>("optimisationDict");
+
+            adjointSensitivity_().readDict
+            (
+                optDict.subDict("optimisation").subDict("sensitivities")
+            );
+        }
+
+        return true;
+    }
+
+    return false;
+}
+
+
+void Foam::adjointPiso::solveIter()
+{
+    // Retrieve primal fields of the time step. Retrieving of the first
+    // time-step of the adjoint loop is also necessary if more than one adjoint
+    // solvers are used. Includes potential recomputation of the primal fields,
+    // depending on the primal storage strategy
+    primalStorage_->retrieveVariables();
+    const Time& time = mesh_.time();
+    Info << "Time = " << time.timeName() << "\n" << endl;
+    printPrimalFields();
+
+    // Update objective related fields
+    objectiveManagerPtr_->updateOrNullify();
+
+    // Update turbulence model and ATC related terms
+    incompressibleAdjointSolver::updatePrimalBasedQuantities();
+
+    // Grab primal references
+    const surfaceScalarField& phi = primalVars_.phi();
+    // Grab adjoint references
+    volScalarField& pa = adjointVars_.paInst();
+    volVectorField& Ua = adjointVars_.UaInst();
+    surfaceScalarField& phia = adjointVars_.phiaInst();
+    autoPtr<incompressibleAdjoint::adjointRASModel>& adjointTurbulence =
+        adjointVars_.adjointTurbulence();
+    const label& paRefCell = solverControl_().pRefCell();
+    const scalar& paRefValue = solverControl_().pRefValue();
+    fv::options& fvOptions(fv::options::New(this->mesh_));
+
+    CourantNo();
+
+    // Momentum predictor
+    //~~~~~~~~~~~~~~~~~~~
+
+    tmp<fvVectorMatrix> tUaEqn
+    (
+        fvm::ddt(Ua) + fvm::div(-phi, Ua)
+      + adjointTurbulence->divDevReff(Ua)
+      + adjointTurbulence->adjointMeanFlowSource()
+      ==
+        fvOptions(Ua)
+    );
+    fvVectorMatrix& UaEqn = tUaEqn.ref();
+
+    // Add sources from boundary conditions
+    UaEqn.boundaryManipulate(Ua.boundaryFieldRef());
+
+    // Add sources from volume-based objectives
+    objectiveManagerPtr_().addUaEqnSource(UaEqn);
+
+    // Add ATC term
+    ATCModel_->addATC(UaEqn);
+
+    UaEqn.relax();
+
+    fvOptions.constrain(UaEqn);
+
+    if (solverControl_().momentumPredictor())
+    {
+        Foam::solve(UaEqn == -fvc::grad(pa));
+
+        fvOptions.correct(Ua);
+    }
+
+    // Pressure Eq
+    //~~~~~~~~~~~~
+    while (solverControl_().correct())
+    {
+        volScalarField rAUa(1.0/UaEqn.A());
+        volVectorField HabyA(constrainHbyA(rAUa*UaEqn.H(), Ua, pa));
+        surfaceScalarField phiaHbyA
+        (
+            "phiaHbyA",
+            fvc::flux(HabyA)
+          //+ MRF_.zeroFilter(fvc::interpolate(rAU)*fvc::ddtCorr(U, phi))
+        );
+        adjustPhi(phiaHbyA, Ua, pa);
+
+        // Non-orthogonal pressure corrector loop
+        while (solverControl_().correctNonOrthogonal())
+        {
+            fvScalarMatrix paEqn
+            (
+                fvm::laplacian(rAUa, pa) == fvc::div(phiaHbyA)
+            );
+
+            paEqn.boundaryManipulate(pa.boundaryFieldRef());
+
+            fvOptions.constrain(paEqn);
+            paEqn.setReference(paRefCell, paRefValue);
+
+            paEqn.solve
+            (
+                mesh_.solver(pa.select(solverControl_().finalInnerIter()))
+            );
+
+            if (solverControl_().finalNonOrthogonalIter())
+            {
+                phia = phiaHbyA - paEqn.flux();
+            }
+        }
+
+        continuityErrors();
+
+        Ua = HabyA - rAUa*fvc::grad(pa);
+        Ua.correctBoundaryConditions();
+        fvOptions.correct(Ua);
+        pa.correctBoundaryConditions();
+    }
+
+    adjointTurbulence->correct();
+
+    if (solverControl_().printMaxMags())
+    {
+        dimensionedScalar maxUa = max(mag(Ua)());
+        dimensionedScalar maxpa = max(mag(pa)());
+        Info<< "Max mag of adjoint velocity = " << maxUa.value() << endl;
+        Info<< "Max mag of adjoint pressure = " << maxpa.value() << endl;
+    }
+
+    // Average fields if necessary
+    adjointVars_.computeMeanUnsteadyFields(timeManip_.primalEndTime());
+
+    // Calls time.write()
+    solverControl_().writeFields();
+
+    // Print execution time
+    time.printExecutionTime(Info);
+
+    printFields();
+}
+
+
+void Foam::adjointPiso::solve()
+{
+    // Iterate
+    if (active_)
+    {
+        preLoop();
+        while (loop())
+        {
+            this->solveIter();
+            accumulateSensitivities();
+        }
+        postLoop();
+    }
+}
+
+
+bool Foam::adjointPiso::loop()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    return time.reverseLoop();
+}
+
+
+void Foam::adjointPiso::preLoop()
+{
+    // Disable re-writting of primal fields
+    primalVars_.setWriteOption(IOobject::NO_WRITE);
+
+    // Reset time to the beginning of the adjoint loop.
+    // Resets endTime too
+    timeManip_.moveToAdjointStartTime();
+
+    //  TODO: To be able to stop the adjoint solution midway and continue
+    //  thereafter, the oldTimes of the adjoint fields are required to be
+    //  correctly read.  Make sure that these are not reset due to change in
+    //  time, upon calling oldTime() function.
+
+    //  Reset all adjoint fields to zero
+    adjointVars_.nullify();
+    adjointVars_.resetMeanFields();
+
+    // Copy pointers to storage instances and possibly read compressed fields
+    // in cases of restarted runs
+    primalStorage_->preAdjointLoop();
+
+    // The adjoint equations should be also solved at the last primal time-step.
+    // Advance time once more to get to the correct time during the solution
+    // of the first adjoint time-setp
+    const_cast<Time&>(mesh_.time())++;
+
+    // Print out
+    Info<< nl << "- - - - - - - - - - - - - - - - - - - - -" << endl;
+    Info<< "Solving adjoint equations for solver " << solverName() << endl;
+    Info<< "- - - - - - - - - - - - - - - - - - - - -" << nl << endl;
+
+    printFields();
+}
+
+
+void Foam::adjointPiso::postLoop()
+{
+    // Write adjoint fields at primalEndTime. Although the adjoint equations
+    // are integrated backwards in time starting from primalEndTime and ending
+    // at primalStartTime, the appropriate time to write the adjoint fields is
+    // the primalEndTime. This is not only to have both the primal and adjoint
+    // fields of each optimization cycle written at the same time, but more
+    // importantly to have consistency between the written grid and the adjoint
+    // fields. To do so, reset only the time value to that corresponding to the
+    // end of the primal. Keep the timeIndex unchanged, so that
+    // GeometricField::storeOldTime() is not called by the time
+    // GeometricField::oldTime() is called from
+    // incompressibleAdjointVars::write(). This way, the adjoint
+    // fields will be written correctly in disk without oldTimes been
+    // shifted
+    Time& time = const_cast<Time&>(mesh_.time());
+    timeManip_.moveToAdjointStartTime(false, false);
+    if (!time.writeTime())
+    {
+        adjointVars_.write();
+    }
+    // Completely reset time to that corresponding to the end of the primal
+    // problem.
+    timeManip_.moveToAdjointStartTime();
+    // Write data except for the adjoint fields that have already been written
+    if (!time.writeTime())
+    {
+        adjointVars_.setWriteOption(IOobject::NO_WRITE);
+        time.writeNow();
+        this->writeNow();
+        adjointVars_.setWriteOption(IOobject::AUTO_WRITE);
+    }
+
+    // Print useful info and rewind storage pointers
+    primalStorage_->postAdjointLoop();
+
+    // Compute sensitivities
+    adjointSolver::postLoop();
+
+    // Re-enable writting of primal fields
+    primalVars_.setWriteOption(IOobject::AUTO_WRITE);
+}
+
+
+void Foam::adjointPiso::postLineSearch()
+{
+    // Set integration times for the next optimisation cycle
+    objectiveManagerPtr_().incrementIntegrationTimes(timeManip_.span());
+}
+
+
+void Foam::adjointPiso::computeObjectiveSensitivities()
+{
+    if (computeSensitivities_)
+    {
+        const scalarField& sens = adjointSensitivity_->calculateSensitivities();
+        if (!sensitivities_)
+        {
+            sensitivities_.reset(new scalarField(sens.size(), scalar(0)));
+        }
+        sensitivities_.ref() = sens;
+    }
+    else
+    {
+        sensitivities_.reset(new scalarField(0));
+    }
+}
+
+
+const Foam::scalarField& Foam::adjointPiso::getObjectiveSensitivities()
+{
+    if (!sensitivities_.valid())
+    {
+        computeObjectiveSensitivities();
+    }
+
+    return sensitivities_();
+}
+
+
+void Foam::adjointPiso::clearSensitivities()
+{
+    if (computeSensitivities_)
+    {
+        adjointSensitivity_->clearSensitivities();
+        adjointSolver::clearSensitivities();
+    }
+}
+
+
+Foam::sensitivity& Foam::adjointPiso::getSensitivityBase()
+{
+    if (adjointSensitivity_.valid())
+    {
+        return adjointSensitivity_();
+    }
+    else
+    {
+        FatalErrorInFunction
+            << "Sensitivity object not allocated \n"
+            << "Turn computeSensitivities on in "
+            << solverName_
+            << nl << nl
+            << exit(FatalError);
+
+        return adjointSensitivity_();
+    }
+}
+
+
+void Foam::adjointPiso::updatePrimalBasedQuantities()
+{
+    // Update turbulence model and ATC related terms
+    incompressibleAdjointSolver::updatePrimalBasedQuantities();
+
+    // Write mean values for all objectives
+    PtrList<objective>& objectives
+        = objectiveManagerPtr_->getObjectiveFunctions();
+    for (objective& obj : objectives)
+    {
+        if (obj.shouldWrite())
+        {
+            obj.writeMeanValue();
+        }
+    }
+}
+
+
+bool Foam::adjointPiso::writeData(Ostream& os) const
+{
+    os.writeEntry("averageIter", solverControl_().averageIter());
+    return adjointSolver::writeData(os);
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolvers/incompressible/adjointPiso/adjointPiso.H

@@ -0,0 +1,202 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::adjointPiso
+
+Description
+    Solution of the incompressible, unsteady adjoint equations using the PISO
+    algorithm
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef adjointPiso_H
+#define adjointPiso_H
+
+#include "incompressibleAdjointSolver.H"
+#include "PISOControl.H"
+#include "incompressibleVars.H"
+#include "incompressibleAdjointVars.H"
+#include "adjointSensitivityIncompressible.H"
+#include "primalStorage.H"
+#include "unsteadyTimeManipulation.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                         Class adjointPiso Declaration
+\*---------------------------------------------------------------------------*/
+
+class adjointPiso
+:
+    public incompressibleAdjointSolver
+{
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        adjointPiso(const adjointPiso&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const adjointPiso&) = delete;
+
+
+protected:
+
+    // Protected data
+
+        //- Solver control
+        autoPtr<PISOControl> solverControl_;
+
+        //- Reference to incompressibleAdjointVars
+        //  Used for convenience and to avoid repetitive dynamic_casts
+        //  Same as getAdjointVars()
+        incompressibleAdjointVars& adjointVars_;
+
+        //- Cumulative continuity error
+        scalar cumulativeContErr_;
+
+        //- Sensitivity Derivatives engine
+        autoPtr<incompressible::adjointSensitivity> adjointSensitivity_;
+
+        //- Reference to primal storage mechanism
+        autoPtr<primalStorage>& primalStorage_;
+
+        //- Time manipulation, common for all primal and adjoint solvers
+        unsteadyTimeManipulation& timeManip_;
+
+
+    // Protected Member Functions
+
+        //- Print adjoint fields if in debug mode
+        void printFields();
+
+        //- Print primal fields if in debug mode
+        void printPrimalFields();
+
+        //- Allocate incompressibleAdjointVars and return reference to be used
+        //- for convenience in the rest of the class.
+        incompressibleAdjointVars& allocateVars();
+
+        //- Compute Courant No
+        void CourantNo() const;
+
+        //- Compute continuity errors
+        void continuityErrors();
+
+        //- Accumulate sensitivities from the various time instances
+        void accumulateSensitivities();
+
+
+public:
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("adjointPiso");
+
+
+    // Constructors
+
+        //- Construct from mesh and dictionary
+        adjointPiso
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const dictionary& dict,
+            const word& primalSolverName
+        );
+
+
+    //- Destructor
+    virtual ~adjointPiso() = default;
+
+
+    // Member Functions
+
+        virtual bool readDict(const dictionary& dict);
+
+        // Evolution
+
+            //- Execute one iteration of the solution algorithm
+            virtual void solveIter();
+
+            //- Main control loop
+            virtual void solve();
+
+            //- Looper (advances iters, time step)
+            virtual bool loop();
+
+            //- Functions to be called before loop
+            virtual void preLoop();
+
+            //- Functions to be called after loop
+            virtual void postLoop();
+
+            //- Functions to be called after the convergence of linearSearch
+            virtual void postLineSearch();
+
+            //- Compute sensitivities of the underlaying objectives
+            virtual void computeObjectiveSensitivities();
+
+            //- Grab a reference to the computed sensitivities
+            virtual const scalarField& getObjectiveSensitivities();
+
+            //- Clears the sensitivity field known by the adjoint solver
+            //- and zeros sensitivities constituents
+            virtual void clearSensitivities();
+
+            //- Return the base sensitivity object
+            virtual sensitivity& getSensitivityBase();
+
+            //- Update primal based quantities
+            //- related to the objective functions.
+            //  Also writes the objective function values to files.
+            //  Written here and not in the postLoop function of the primal
+            //  to make sure we don't pollute the objective files with
+            //  objectives of non-converged linearSearch iterations
+            virtual void updatePrimalBasedQuantities();
+
+            //- Write average iteration
+            virtual bool writeData(Ostream& os) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolvers/incompressible/adjointSimple/adjointSimple.C

@@ -66,20 +66,6 @@ Foam::incompressibleAdjointVars& Foam::adjointSimple::allocateVars()
 }
 
 
-void Foam::adjointSimple::addExtraSchemes()
-{
-    if (adjointVars_.useSolverNameForFields())
-    {
-        WarningInFunction
-            << "useSolverNameForFields is set to true for adjointSolver "
-            << solverName() << nl << tab
-            << "Appending variable names with the solver name" << nl << tab
-            << "Please adjust the necessary entries in fvSchemes and fvSolution"
-            << nl << endl;
-    }
-}
-
-
 void Foam::adjointSimple::continuityErrors()
 {
     const surfaceScalarField& phia = adjointVars_.phiaInst();

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolvers/incompressible/adjointSimple/adjointSimple.H

@@ -103,13 +103,6 @@ protected:
         //- for convenience in the rest of the class.
         incompressibleAdjointVars& allocateVars();
 
-        //- In case variable names are different than the base ones,
-        //- add extra schemes and relaxation factors to the appropriate dicts
-        //  Note: 160813: Changes in the baseline solution and fvSchemes classes
-        //  have to be made in order to add schemes in the dict at run time.
-        //  Not supported for now
-        void addExtraSchemes();
-
         //- Compute continuity errors
         void continuityErrors();
 

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolvers/incompressible/incompressibleAdjointSolver/incompressibleAdjointSolver.C

@@ -47,6 +47,22 @@ namespace Foam
 }
 
 
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::incompressibleAdjointSolver::addExtraSchemes()
+{
+    if (vars_().useSolverNameForFields())
+    {
+        WarningInFunction
+            << "useSolverNameForFields is set to true for adjointSolver "
+            << solverName() << nl << tab
+            << "Appending variable names with the solver name" << nl << tab
+            << "Please adjust the necessary entries in fvSchemes and fvSolution"
+            << nl << endl;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 Foam::incompressibleAdjointSolver::incompressibleAdjointSolver

src/optimisation/adjointOptimisation/adjoint/solvers/adjointSolvers/incompressible/incompressibleAdjointSolver/incompressibleAdjointSolver.H

@@ -80,6 +80,15 @@ protected:
         autoPtr<ATCModel> ATCModel_;
 
 
+    // Protected Member Functions
+
+        //- In case variable names are different than the base ones,
+        //- add extra schemes and relaxation factors to the appropriate dicts
+        //  Note: 160813: Changes in the baseline solution and fvSchemes classes
+        //  have to be made in order to add schemes in the dict at run time.
+        //  Not supported for now
+        void addExtraSchemes();
+
 public:
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/RASTurbulenceModel/RASTurbulenceModel.C

@@ -61,10 +61,11 @@ Foam::RASTurbulenceModel::RASTurbulenceModel
 (
     fvMesh& mesh,
     const word& managerType,
-    const dictionary& dict
+    const dictionary& dict,
+    Switch useCustomReadTime
 )
 :
-    incompressiblePrimalSolver(mesh, managerType, dict),
+    incompressiblePrimalSolver(mesh, managerType, dict, useCustomReadTime),
     solverControl_(SIMPLEControl::New(mesh, managerType, *this)),
     incoVars_(allocateVars())
 {

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/RASTurbulenceModel/RASTurbulenceModel.H

@@ -98,7 +98,8 @@ public:
         (
             fvMesh& mesh,
             const word& managerType,
-            const dictionary& dict
+            const dictionary& dict,
+            Switch useCustomReadTime = false
         );
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/incompressiblePrimalSolver/incompressiblePrimalSolver.C

@@ -48,6 +48,21 @@ namespace Foam
     );
 }
 
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::incompressiblePrimalSolver::addExtraSchemes()
+{
+    if (vars_().useSolverNameForFields())
+    {
+        WarningInFunction
+            << "useSolverNameForFields is set to true for primalSolver "
+            << solverName() << nl << tab
+            << "Appending variable names with the solver name" << nl << tab
+            << "Please adjust the necessary entries in fvSchemes and fvSolution"
+            << nl << endl;
+    }
+}
+
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
@@ -55,10 +70,11 @@ Foam::incompressiblePrimalSolver::incompressiblePrimalSolver
 (
     fvMesh& mesh,
     const word& managerType,
-    const dictionary& dict
+    const dictionary& dict,
+    Switch useCustomReadTime
 )
 :
-    primalSolver(mesh, managerType, dict),
+    primalSolver(mesh, managerType, dict, useCustomReadTime),
     phiReconstructionTol_
     (
         dict.subOrEmptyDict("fieldReconstruction").
@@ -79,7 +95,8 @@ Foam::incompressiblePrimalSolver::New
 (
     fvMesh& mesh,
     const word& managerType,
-    const dictionary& dict
+    const dictionary& dict,
+    Switch useCustomReadTime
 )
 {
     const word solverType(dict.get<word>("solver"));
@@ -99,7 +116,7 @@ Foam::incompressiblePrimalSolver::New
     return
         autoPtr<incompressiblePrimalSolver>
         (
-            ctorPtr(mesh, managerType, dict)
+            ctorPtr(mesh, managerType, dict, useCustomReadTime)
         );
 }
 

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/incompressiblePrimalSolver/incompressiblePrimalSolver.H

@@ -77,6 +77,14 @@ protected:
         label phiReconstructionIters_;
 
 
+    //- Protected Member Functions
+
+        //- In case variable names are different than the base ones,
+        //- add extra schemes and relaxation factors to the appropriate dicts
+        //  Note: Not supported for now
+        void addExtraSchemes();
+
+
 public:
 
 
@@ -96,9 +104,10 @@ public:
             (
                 fvMesh& mesh,
                 const word& managerType,
-                const dictionary& dict
+                const dictionary& dict,
+                Switch useCustomReadTime
             ),
-            (mesh, managerType, dict)
+            (mesh, managerType, dict, useCustomReadTime)
         );
 
 
@@ -109,7 +118,8 @@ public:
         (
             fvMesh& mesh,
             const word& managerType,
-            const dictionary& dict
+            const dictionary& dict,
+            Switch useCustomReadTime = false
         );
 
 
@@ -120,7 +130,8 @@ public:
         (
             fvMesh& mesh,
             const word& managerType,
-            const dictionary& dict
+            const dictionary& dict,
+            Switch useCustomReadTime = false
         );
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/pimple/pimple.C

@@ -0,0 +1,686 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "pimple.H"
+#include "findRefCell.H"
+#include "constrainHbyA.H"
+#include "constrainPressure.H"
+#include "adjustPhi.H"
+#include "CorrectPhi.H"
+#include "Time.H"
+#include "fvOptions.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(pimple, 0);
+    addToRunTimeSelectionTable
+    (
+        incompressiblePrimalSolver,
+        pimple,
+        dictionary
+    );
+}
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+Foam::incompressibleVars& Foam::pimple::allocateVars(scalar readTime)
+{
+    vars_.reset(new incompressibleVars(mesh_, solverControl_(), readTime));
+    return getIncoVars();
+}
+
+
+void Foam::pimple::readTimeControls()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/general/include/readTimeControls.H
+    const Time& runTime = mesh_.time();
+    bool& adjustTimeStep = adjustTimeStep_;
+    scalar& maxCo = maxCo_;
+    scalar& maxDeltaT = maxDeltaT_;
+    #include "readTimeControls.H"
+}
+
+
+void Foam::pimple::CourantNo()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/incompressible/CourantNo.H
+    const surfaceScalarField& phi = incoVars_.phiInst();
+    const Time& runTime = mesh_.time();
+    const fvMesh& mesh = mesh_;
+    #include "CourantNo.H"
+    CoNum_ = CoNum;
+}
+
+
+void Foam::pimple::continuityErrors()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/incompressible/continuityErrs.H
+    const Time& runTime = mesh_.time();
+    const fvMesh& mesh = mesh_;
+    const surfaceScalarField& phi = incoVars_.phiInst();
+    scalar& cumulativeContErr = cumulativeContErr_;
+    #include "continuityErrs.H"
+}
+
+
+void Foam::pimple::setDeltaT()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/general/include/setDeltaT.H
+    Time& runTime = const_cast<Time&>(mesh_.time());
+    bool& adjustTimeStep = adjustTimeStep_;
+    scalar& maxCo = maxCo_;
+    scalar& maxDeltaT = maxDeltaT_;
+    scalar& CoNum = CoNum_;
+    #include "setDeltaT.H"
+}
+
+
+void Foam::pimple::setInitialDeltaT()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/general/include/setInitialDeltaT.H
+    Time& runTime = const_cast<Time&>(mesh_.time());
+    const bool& adjustTimeStep = adjustTimeStep_;
+    const scalar& CoNum = CoNum_;
+    const scalar& maxCo = maxCo_;
+    const scalar& maxDeltaT = maxDeltaT_;
+    #include "setInitialDeltaT.H"
+}
+
+
+void Foam::pimple::setTime()
+{
+    Time& runTime = const_cast<Time&>(mesh_.time());
+    ++runTime;
+}
+
+
+void Foam::pimple::storeDeltaT()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    if (adjustTimeStep_)
+    {
+        DebugInfo
+            << "time.timeIndex() - primalStartTimeIndex = "
+            << time.timeIndex() - timeManip_.startTimeIndex() << nl
+            << "time.timeIndex(), primalStartTimeIndex  = "
+            << time.timeIndex() << " " << timeManip_.startTimeIndex()
+            << endl;
+        if
+        (
+            deltaTList_.empty()
+         && (time.timeIndex() > timeManip_.startTimeIndex())
+        )
+        {
+            deltaTList_.
+                setSize
+                (
+                    time.timeIndex() - timeManip_.startTimeIndex(),
+                    deltaT0_
+                );
+        }
+        deltaTList_.append(time.deltaTValue());
+    }
+    DebugInfo
+        << "deltaTList.size() = " << deltaTList_.size() << endl;
+}
+
+
+void Foam::pimple::scratchDeltaTHistory()
+{
+    const Time& time = mesh_.time();
+    deltaT0_ = time.deltaTValue();
+    primalStartTimeIndex_ = time.timeIndex();
+    deltaTList_.clear();
+}
+
+
+const Foam::DynamicList<Foam::scalar>& Foam::pimple::getDeltaTList() const
+{
+    return deltaTList_;
+}
+
+
+/*void Foam::pimple::readDyMControls()
+{
+    // Original function at src/dynamicFvMesh/include/readDyMControls.H
+    // Original function at
+    // src/finiteVolume/cfdTools/general/include/readTimeControls.H
+    const Time& runTime = mesh_.time();
+    const PIMPLEControl& pimple = solverControl_();
+    bool& moveMeshOuterCorrectors = moveMeshOuterCorrectors_;
+    bool& checkMeshCourantNo = checkMeshCourantNo_;
+    bool& correctPhi = correctPhi_;
+    bool& adjustTimeStep = adjustTimeStep_;
+    scalar& maxCo = maxCo_;
+    scalar& maxDeltaT = maxDeltaT_;
+    #include "readDyMControls.H"
+}
+
+
+void Foam::pimple::meshCourantNo()
+{
+    // Original function at src/dynamicFvMesh/include/meshCourantNo.H
+    const Time& runTime = mesh_.time();
+    const fvMesh& mesh = mesh_;
+    #include "meshCourantNo.H"
+}
+
+
+void Foam::pimple::correctPhi()
+{
+    // Original function at the location of the solver
+    // CorrectPhi at src/finiteVolume/cfdTools/general/CorrectPhi/CorrectPhi.H
+    volScalarField& p = incoVars_.pInst();
+    volVectorField& U = incoVars_.UInst();
+    surfaceScalarField& phi = incoVars_.phiInst();
+    CorrectPhi
+    (
+        U,
+        phi,
+        p,
+        dimensionedScalar("rAUf", dimTime, 1),
+        geometricZeroField(),
+        solverControl_()
+    );
+    continuityErrors();
+}
+
+
+void Foam::pimple::createUfIfPresent()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/incompressible/createUfIfPresent.H
+    if (mesh_.dynamic())
+    {
+        volVectorField& U = incoVars_.UInst();
+
+        Info<< "Constructing face velocity Uf\n" << endl;
+
+        Uf_.reset
+        (
+            new surfaceVectorField
+            (
+                IOobject
+                (
+                    "Uf",
+                    mesh_.time().timeName(),
+                    mesh_,
+                    IOobject::READ_IF_PRESENT,
+                    IOobject::AUTO_WRITE
+                ),
+                fvc::interpolate(U)
+            )
+        );
+    }
+}*/
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::pimple::pimple
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const dictionary& dict,
+    Switch useCustomReadTime
+)
+:
+    incompressiblePrimalSolver
+    (
+        mesh,
+        managerType,
+        dict,
+        useCustomReadTime
+    ),
+    solverControl_(PIMPLEControl::New(mesh, managerType, *this)),
+    shouldResetMeanFields_(useCustomReadTime),
+    incoVars_
+    (
+        allocateVars
+        (
+            useCustomReadTime ? dict.getOrDefault<scalar>("readTime", 0) : -1
+        )
+    ),
+    MRF_(mesh, word(useSolverNameForFields() ? solverName() : word::null)),
+    cumulativeContErr_(Zero),
+    objectives_(0),
+    adjustTimeStep_
+    (
+        mesh.time().controlDict().getOrDefault("adjustTimeStep", false)
+    ),
+    maxCo_
+    (
+        mesh.time().controlDict().getOrDefault<scalar>("maxCo", 1.0)
+    ),
+    maxDeltaT_
+    (
+        mesh.time().controlDict().getOrDefault<scalar>("maxDeltaT", GREAT)
+    ),
+    primalStartTimeIndex_(mesh_.time().timeIndex()),
+    deltaTList_(0),
+    timeManip_
+    (
+        const_cast<unsteadyTimeManipulation&>
+        (
+            unsteadyTimeManipulation::New(mesh)
+        )
+    )
+    /*correctPhi_
+    (
+        solverControl_().dict().getOrDefault("correctPhi", mesh_.dynamic())
+    ),
+    checkMeshCourantNo_
+    (
+        solverControl_().dict().getOrDefault("checkMeshCourantNo", false)
+    ),
+    moveMeshOuterCorrectors_
+    (
+        solverControl_().dict().getOrDefault("moveMeshOuterCorrectors", false)
+    )*/
+{
+    addExtraSchemes();
+    setRefCell
+    (
+        incoVars_.pInst(),
+        solverControl_().dict(),
+        solverControl_().pRefCell(),
+        solverControl_().pRefValue()
+    );
+
+    // Decide primal storage mechanism
+    if (dict.isDict("storage"))
+    {
+        primalStorage_.reset
+        (
+            primalStorage::New(*this, dict.subDict("storage"))
+        );
+    }
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+bool Foam::pimple::readDict(const dictionary& dict)
+{
+    if (incompressiblePrimalSolver::readDict(dict))
+    {
+        return true;
+    }
+
+    return false;
+}
+
+
+void Foam::pimple::solveIter()
+{
+    const Time& time = mesh_.time();
+    //readDyMControls();
+    readTimeControls();
+    setDeltaT();
+    storeDeltaT();
+    setTime();
+
+    // The primal solution at the first time-step does not need to be stored.
+    // When checkpointing is used, the checkpoint at the first time step must
+    // be set, else storeInitialVariables() does nothing
+    if (primalStorage_.valid())
+    {
+        if (time.timeIndex() == timeManip_.startTimeIndex() + 1)
+        {
+            primalStorage_().storeInitialVariables();
+        }
+        else
+        {
+            primalStorage_().storeVariables();
+        }
+    }
+    Info<< "Time = " << mesh_.time().timeName() << "\n" << endl;
+
+    // Grab references
+    volScalarField& p = incoVars_.pInst();
+    volVectorField& U = incoVars_.UInst();
+    surfaceScalarField& phi = incoVars_.phiInst();
+    autoPtr<incompressible::turbulenceModel>& turbulence =
+        incoVars_.turbulence();
+    label&  pRefCell = solverControl_().pRefCell();
+    scalar& pRefValue = solverControl_().pRefValue();
+    fv::options& fvOptions(fv::options::New(this->mesh_));
+
+    CourantNo();
+
+    while (solverControl_().loop())
+    {
+        // No moving geometries supported for now
+        /*
+        if (solverControl_().firstIter() || moveMeshOuterCorrectors_)
+        {
+            //mesh_.update();
+
+            if (mesh_.changing())
+            {
+                MRF_.update();
+
+                if (correctPhi_)
+                {
+                    // Calculate absolute flux
+                    // from the mapped surface velocity
+                    phi = mesh_.Sf() & Uf_();
+
+                    correctPhi();
+
+                    // Make the flux relative to the mesh motion
+                    fvc::makeRelative(phi, U);
+                }
+                if (checkMeshCourantNo_)
+                {
+                    meshCourantNo();
+                }
+            }
+        }
+        */
+
+        // Momentum predictor
+        //~~~~~~~~~~~~~~~~~~~
+
+        MRF_.correctBoundaryVelocity(U);
+
+        tmp<fvVectorMatrix> tUEqn
+        (
+            fvm::ddt(U) + fvm::div(phi, U)
+          + MRF_.DDt(U)
+          + turbulence->divDevReff(U)
+          ==
+            fvOptions(U)
+        );
+        fvVectorMatrix& UEqn = tUEqn.ref();
+
+        UEqn.relax();
+
+        fvOptions.constrain(UEqn);
+
+        if (solverControl_().momentumPredictor())
+        {
+            Foam::solve(UEqn == -fvc::grad(p));
+
+            fvOptions.correct(U);
+        }
+        // Pressure Eq
+        //~~~~~~~~~~~~
+        while (solverControl_().correct())
+        {
+            volScalarField rAU(1.0/UEqn.A());
+            volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
+            surfaceScalarField phiHbyA
+            (
+                "phiHbyA",
+                fvc::flux(HbyA)
+              + MRF_.zeroFilter(fvc::interpolate(rAU)*fvc::ddtCorr(U, phi, Uf_))
+            );
+
+            MRF_.makeRelative(phiHbyA);
+
+            if (p.needReference())
+            {
+                fvc::makeRelative(phiHbyA, U);
+                adjustPhi(phiHbyA, U, p);
+                fvc::makeAbsolute(phiHbyA, U);
+            }
+
+            tmp<volScalarField> rAtU(rAU);
+
+            if (solverControl_().consistent())
+            {
+                rAtU = 1.0/max(1.0/rAU - UEqn.H1(), 0.1/rAU);
+                phiHbyA +=
+                    fvc::interpolate(rAtU() - rAU)*fvc::snGrad(p)*mesh_.magSf();
+                HbyA -= (rAU - rAtU())*fvc::grad(p);
+            }
+
+            if (solverControl_().nCorrPISO() <= 1)
+            {
+                tUEqn.clear();
+            }
+
+            // Update the pressure BCs to ensure flux consistency
+            constrainPressure(p, U, phiHbyA, rAtU(), MRF_);
+
+            // Non-orthogonal pressure corrector loop
+            while (solverControl_().correctNonOrthogonal())
+            {
+                fvScalarMatrix pEqn
+                (
+                    fvm::laplacian(rAtU(), p) == fvc::div(phiHbyA)
+                );
+
+                pEqn.setReference(pRefCell, pRefValue);
+
+                fvOptions.constrain(pEqn);
+
+                pEqn.solve
+                (
+                    mesh_.solver(p.select(solverControl_().finalInnerIter()))
+                );
+
+                if (solverControl_().finalNonOrthogonalIter())
+                {
+                    phi = phiHbyA - pEqn.flux();
+                }
+            }
+
+            continuityErrors();
+
+            // Explicitly relax pressure for momentum corrector
+            p.relax();
+
+            U = HbyA - rAtU*fvc::grad(p);
+            U.correctBoundaryConditions();
+            fvOptions.correct(U);
+
+            // Correct Uf if the mesh is moving
+            fvc::correctUf(Uf_, U, phi);
+
+            // Make the fluxes relative to the mesh motion
+            fvc::makeRelative(phi, U);
+        }
+
+        if (solverControl_().turbCorr())
+        {
+            incoVars_.laminarTransport().correct();
+            turbulence->correct();
+        }
+    }
+
+    // Print objective values to screen and compute mean value
+    Info<< nl;
+    for (objective* obj : objectives_)
+    {
+        Info<< obj->objectiveName() << " : " << obj->J() << endl;
+        obj->accumulateJMean();
+        obj->writeInstantaneousValue();
+    }
+
+    // Average fields if necessary
+    incoVars_.computeMeanUnsteadyFields();
+
+    // Calls time.write()
+    solverControl_().writeFields();
+
+    // Print execution time
+    time.printExecutionTime(Info);
+}
+
+
+void Foam::pimple::solve()
+{
+    // Iterate
+    if (active_)
+    {
+        preLoop();
+        while (loop())
+        {
+            solveIter();
+        }
+        postLoop();
+    }
+}
+
+
+bool Foam::pimple::run()
+{
+  //return solverControl_().run();
+    return mesh_.time().run();
+}
+
+
+bool Foam::pimple::loop()
+{
+    // mesh_.time().run() is actually needed here. Not a mistake.
+    // Chosen for compatibility reasons with the simple and piso algorithms
+    // and the 'solveWithArgs' function at solverTemplates.C
+    return mesh_.time().run();
+}
+
+
+void Foam::pimple::restoreInitValues()
+{
+    incoVars_.restoreInitValues();
+}
+
+
+void Foam::pimple::preLoop()
+{
+    // Move to the correct time, if changed by a previous primal solver
+    timeManip_.moveToPrimalStartTime();
+
+    // Get the objectives for this solver
+    if (objectives_.empty())
+    {
+        objectives_ = getObjectiveFunctions();
+    }
+
+    // Reset initial and mean fields before solving
+    restoreInitValues();
+    if (shouldResetMeanFields_)
+    {
+        incoVars_.resetMeanFields();
+    }
+
+    // Validate turbulence model fields
+    incoVars_.turbulence()->validate();
+
+    // nullify JMean for all objectives
+    for (objective* obj : objectives_)
+    {
+        obj->resetJMean();
+    }
+
+    // Reset primal storage
+    if (primalStorage_.valid())
+    {
+        primalStorage_().scratch();
+    }
+    scratchDeltaTHistory();
+    CourantNo();
+    //createUfIfPresent();
+    setInitialDeltaT();
+
+    // Print out
+    Info<< nl << "- - - - - - - - - - - - - - - - - - - - -" << endl;
+    Info<< "Solving primal equations for solver " << solverName() << endl;
+    Info<< "- - - - - - - - - - - - - - - - - - - - -" << nl << endl;
+}
+
+
+void Foam::pimple::postLoop()
+{
+    // Store last time instance. Redundant if a single adjoint solver is used,
+    // but necessary for more than one adjoint solvers
+    if (primalStorage_.valid())
+    {
+        // Advance time to avoid implications with the checkpointing
+        // implementation and store variables
+        timeManip_.storeTime();
+        const_cast<Time&>(mesh_.time())++;
+        primalStorage_().storeVariables();
+
+        // Retrive time
+        timeManip_.restoreTime();
+
+        // Print storage metrics
+        primalStorage_().storageMetrics();
+    }
+
+    // Write separators in objective files
+    for (objective* obj : objectives_)
+    {
+        obj->writeInstantaneousSeparator();
+    }
+    // Safety
+    objectives_.clear();
+
+    // Avoid writting fields if already in an outputTime iter
+    // since results will be written by the solver class either way
+    Time& time = const_cast<Time&>(mesh_.time());
+    if (!time.writeTime())
+    {
+        // Write all fields
+        time.writeNow();
+        // Write dummy turbulence fields if multiple primal solvers exist
+        this->writeNow();
+    }
+
+    // Allow mean fields to be zeroed at the next call of preLoop
+    shouldResetMeanFields_ = true;
+
+    // Store endTimeIndex, to be retrieved later by the adjoint
+    timeManip_.storeEndTimeIndex();
+}
+
+
+void Foam::pimple::postLineSearch()
+{
+    // Update averaging window for the next optimisation cycle
+    solverControl_().updateAverageStartTime();
+}
+
+
+bool Foam::pimple::writeData(Ostream& os) const
+{
+    os.writeEntry("averageIter", solverControl_().averageIter());
+
+    return true;
+}
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/pimple/pimple.H

@@ -0,0 +1,240 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::pimple
+
+Description
+    Base class for solution control classes
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef pimple_H
+#define pimple_H
+
+#include "incompressiblePrimalSolver.H"
+#include "PIMPLEControl.H"
+#include "IOMRFZoneList.H"
+#include "objective.H"
+#include "unsteadyTimeManipulation.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                            Class pimple Declaration
+\*---------------------------------------------------------------------------*/
+
+class pimple
+:
+    public incompressiblePrimalSolver
+{
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        pimple(const pimple&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const pimple&) = delete;
+
+
+protected:
+
+    // Protected data
+
+        //- Solver control
+        autoPtr<PIMPLEControl> solverControl_;
+
+        //- Boolean defining if primal fields will be initialized from
+        //  the current or a costum time-step provided by the user
+        Switch shouldResetMeanFields_;
+
+        //- Reference to incompressibleVars
+        //  Used for convenience and to avoid repetitive dynamic_casts
+        //  Same as getIncoVars()
+        incompressibleVars& incoVars_;
+
+        //- MRF zones
+        IOMRFZoneList MRF_;
+
+        //- Cumulative continuity error
+        scalar cumulativeContErr_;
+
+        //- List of objectives related to this primal solver
+        List<objective*> objectives_;
+
+        //- Boolean and scalar entries for readDyMControls and
+        //  setDeltaT functions
+        bool adjustTimeStep_;
+        scalar maxCo_;
+        scalar maxDeltaT_;
+        scalar CoNum_;
+        /*bool correctPhi_;
+        bool checkMeshCourantNo_;
+        bool moveMeshOuterCorrectors_;*/
+
+        //- velocity field Uf (set only if required)
+        autoPtr<surfaceVectorField> Uf_;
+
+        scalar deltaT0_;
+
+        //- Time-index at the beggining of the primal solution
+        label primalStartTimeIndex_;
+
+        //- List with deltaT values during the solution of the primal problem
+        DynamicList<scalar> deltaTList_;
+
+        //- Time manipulation, common for all primal and adjoint solvers
+        unsteadyTimeManipulation& timeManip_;
+
+
+    // Protected Member Functions
+
+        //- Allocate incompressibleVars and return reference to be used for
+        //- convenience in the rest of the class.
+        incompressibleVars& allocateVars(scalar readTime);
+
+        //- Read only the control parameters used by setDeltaT
+        void readTimeControls();
+
+        //- Compute Courant No
+        void CourantNo();
+
+        //- Compute continuity errors
+        void continuityErrors();
+
+        //- Reset time-step to maintain a constant maximum courant Number.
+        //  Reduction of time-step is immediate, but increase is damped to
+        //  avoid unstable oscillations.
+        void setDeltaT();
+
+        //- Set the initial timestep corresponding to the timestep
+        //  adjustment algorithm in setDeltaT but only if it would
+        //  reduce the timestep.
+        void setInitialDeltaT();
+
+        //- Increase time
+        void setTime();
+
+        //- Store the current deltaT
+        void storeDeltaT();
+
+        //- Scratch deltaTList_ and deltaT0_
+        void scratchDeltaTHistory();
+
+        /*
+        //- Read among other the control parameters used by setDeltaT
+        void readDyMControls();
+
+        //- Calculates and outputs the mean and maximum Courant Numbers.
+        void meshCourantNo();
+
+        //- Flux correction functions to ensure continuity
+        void correctPhi();
+
+        //- Creates and initialises the velocity field Uf if required.
+        void createUfIfPresent();
+        */
+
+
+public:
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("pimple");
+
+
+    // Constructors
+
+        //- Construct from mesh and dictionary
+        pimple
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const dictionary& dict,
+            Switch useCustomReadTime = false
+        );
+
+
+    //- Destructor
+    virtual ~pimple() = default;
+
+
+    // Member Functions
+
+        virtual bool readDict(const dictionary& dict) override;
+
+        // Evolution
+
+            //- Execute one iteration of the solution algorithm
+            virtual void solveIter() override;
+
+            //- Main control loop
+            virtual void solve() override;
+
+            //- Looper (advances iters, time step)
+            virtual bool run();
+            virtual bool loop() override;
+
+            //- Restore initial field values if necessary
+            virtual void restoreInitValues() override;
+
+            //- Functions to be called before loop
+            virtual void preLoop() override;
+
+            //- Functions to be called after loop
+            virtual void postLoop() override;
+
+            //- Functions to be called after lineSearch has converged
+            virtual void postLineSearch() override;
+
+            //- Write average iteration
+            virtual bool writeData(Ostream& os) const override;
+
+
+        // Info to the AdjointSolver
+
+            //- Return a scalarList with all deltaT of the primal solution
+            const DynamicList<scalar>& getDeltaTList() const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/piso/piso.C

@@ -0,0 +1,467 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "piso.H"
+#include "findRefCell.H"
+#include "constrainHbyA.H"
+#include "constrainPressure.H"
+#include "adjustPhi.H"
+#include "Time.H"
+#include "fvOptions.H"
+#include "addToRunTimeSelectionTable.H"
+#include "profiling.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(piso, 0);
+    addToRunTimeSelectionTable(incompressiblePrimalSolver, piso, dictionary);
+}
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::piso::printFields()
+{
+    if (debug > 1)
+    {
+        const word timeName = mesh_.time().timeName();
+        const word prefix = "after solving for t = " + timeName + " ";
+        volScalarField& p = incoVars_.pInst();
+        volVectorField& U = incoVars_.UInst();
+        surfaceScalarField& phi = incoVars_.phiInst();
+        Info<< "Debug: U.nOldTimes()   = " << U.nOldTimes() << endl;
+        Info<< "Debug: phi.nOldTimes() = " << phi.nOldTimes() << endl;
+        Info<< prefix << "p:\n" << p << endl;
+        Info<< prefix << "U:\n" << U << endl;
+        Info<< prefix << "U.oldTime():\n" << U.oldTime() << endl;
+        Info<< prefix << "phi:\n" << phi << endl;
+        Info<< prefix << "phi.oldTime():\n" << phi.oldTime() << endl;
+        incompressible::RASModelVariables& rasVars =
+            incoVars_.RASModelVariables()();
+        if (rasVars.hasTMVar1())
+        {
+            Info<< "Debug: TMVar1.nOldTimes() = "
+                << rasVars.TMVar1Inst().nOldTimes() << endl;
+            Info<< prefix << " TMVar1:\n" << rasVars.TMVar1Inst() << endl;
+            Info<< prefix << " TMVar1.oldTime():\n"
+                << rasVars.TMVar1Inst().oldTime() << endl;
+        }
+        if (rasVars.hasTMVar2())
+        {
+            Info<< "Debug: TMVar2.nOldTimes() = "
+                << rasVars.TMVar2Inst().nOldTimes() << endl;
+            Info<< prefix << " TMVar2:\n" << rasVars.TMVar2Inst() << endl;
+            Info<< prefix << " TMVar2.oldTime():\n"
+                << rasVars.TMVar2Inst().oldTime() << endl;
+        }
+        if (rasVars.hasNut())
+        {
+            Info << prefix << " nut:\n" << rasVars.nutRefInst() << endl;
+        }
+    }
+}
+
+
+Foam::incompressibleVars& Foam::piso::allocateVars(scalar readTime)
+{
+    vars_.reset(new incompressibleVars(mesh_, solverControl_(), readTime));
+    return getIncoVars();
+}
+
+
+void Foam::piso::CourantNo() const
+{
+    const surfaceScalarField& phi = incoVars_.phiInst();
+    const Time& runTime = mesh_.time();
+    const fvMesh& mesh = mesh_;
+    #include "CourantNo.H"
+}
+
+
+void Foam::piso::continuityErrors()
+{
+    // Original function at
+    // src/finiteVolume/cfdTools/incompressible/continuityErrs.H
+    const Time& runTime = mesh_.time();
+    const fvMesh& mesh = mesh_;
+    const surfaceScalarField& phi = incoVars_.phiInst();
+    scalar& cumulativeContErr = cumulativeContErr_;
+    #include "continuityErrs.H"
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::piso::piso
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const dictionary& dict,
+    Switch useCustomReadTime
+)
+:
+    incompressiblePrimalSolver
+    (
+        mesh,
+        managerType,
+        dict,
+        useCustomReadTime
+    ),
+    solverControl_(PISOControl::New(mesh, managerType, *this)),
+    shouldResetMeanFields_(useCustomReadTime),
+    incoVars_
+    (
+        allocateVars
+        (
+            useCustomReadTime ? dict.getOrDefault<scalar>("readTime", 0) : -1
+        )
+    ),
+    MRF_(mesh, word(useSolverNameForFields() ? solverName() : word::null)),
+    cumulativeContErr_(Zero),
+    objectives_(0),
+    timeManip_
+    (
+        const_cast<unsteadyTimeManipulation&>
+        (
+            unsteadyTimeManipulation::New(mesh)
+        )
+    )
+{
+    addExtraSchemes();
+    setRefCell
+    (
+        incoVars_.pInst(),
+        solverControl_().dict(),
+        solverControl_().pRefCell(),
+        solverControl_().pRefValue()
+    );
+
+    // Decide primal storage mechanism
+    if (dict.isDict("storage"))
+    {
+        primalStorage_.reset
+        (
+            primalStorage::New(*this, dict.subDict("storage"))
+        );
+    }
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+bool Foam::piso::readDict(const dictionary& dict)
+{
+    if (incompressiblePrimalSolver::readDict(dict))
+    {
+        return true;
+    }
+
+    return false;
+}
+
+
+void Foam::piso::solveIter()
+{
+    addProfiling(piso, "piso::solveIter()");
+    const Time& time = mesh_.time();
+    // The primal solution at the first time-step does not need to be stored.
+    // However, when checkpointing is used, the checkpoint at the first time
+    // step must be set; storeInitialVariables() does nothing in other cases.
+    // Note: would make sense to be at the end of the iteration but
+    // checkpoint intricaties suggest it should remain here
+    if (primalStorage_.valid())
+    {
+        if (time.timeIndex() == timeManip_.startTimeIndex() + 1)
+        {
+            primalStorage_().storeInitialVariables();
+        }
+        else
+        {
+            primalStorage_().storeVariables();
+        }
+    }
+    Info<< "Time = " << mesh_.time().timeName() << "\n" << endl;
+
+    // Grab references
+    volScalarField& p = incoVars_.pInst();
+    volVectorField& U = incoVars_.UInst();
+    surfaceScalarField& phi = incoVars_.phiInst();
+    autoPtr<incompressible::turbulenceModel>& turbulence =
+        incoVars_.turbulence();
+    label&  pRefCell = solverControl_().pRefCell();
+    scalar& pRefValue = solverControl_().pRefValue();
+    fv::options& fvOptions(fv::options::New(this->mesh_));
+
+    CourantNo();
+
+    // Momentum predictor
+    //~~~~~~~~~~~~~~~~~~~
+
+    MRF_.correctBoundaryVelocity(U);
+
+    tmp<fvVectorMatrix> tUEqn
+    (
+        fvm::ddt(U) + fvm::div(phi, U)
+      + MRF_.DDt(U)
+      + turbulence->divDevReff(U)
+      ==
+        fvOptions(U)
+    );
+    fvVectorMatrix& UEqn = tUEqn.ref();
+
+    UEqn.relax();
+
+    fvOptions.constrain(UEqn);
+
+    if (solverControl_().momentumPredictor())
+    {
+        Foam::solve(UEqn == -fvc::grad(p));
+
+        fvOptions.correct(U);
+    }
+
+    // Pressure Eq
+    //~~~~~~~~~~~~
+    while (solverControl_().correct())
+    {
+        volScalarField rAU(1.0/UEqn.A());
+        volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
+        surfaceScalarField phiHbyA
+        (
+            "phiHbyA",
+            fvc::flux(HbyA)
+          + MRF_.zeroFilter(fvc::interpolate(rAU)*fvc::ddtCorr(U, phi))
+        );
+
+        MRF_.makeRelative(phiHbyA);
+
+        adjustPhi(phiHbyA, U, p);
+
+        // Update the pressure BCs to ensure flux consistency
+        constrainPressure(p, U, phiHbyA, rAU, MRF_);
+
+        // Non-orthogonal pressure corrector loop
+        while (solverControl_().correctNonOrthogonal())
+        {
+            fvScalarMatrix pEqn
+            (
+                fvm::laplacian(rAU, p) == fvc::div(phiHbyA)
+            );
+
+            pEqn.setReference(pRefCell, pRefValue);
+
+            fvOptions.constrain(pEqn);
+
+            pEqn.solve
+            (
+                mesh_.solver(p.select(solverControl_().finalInnerIter()))
+            );
+
+            if (solverControl_().finalNonOrthogonalIter())
+            {
+                phi = phiHbyA - pEqn.flux();
+            }
+        }
+
+        continuityErrors();
+
+        U = HbyA - rAU*fvc::grad(p);
+        U.correctBoundaryConditions();
+        fvOptions.correct(U);
+    }
+    // An extra correction of the BC of p would be necessary to have
+    // consistency for p upon reconstruction during the adjoint run.
+    // However, this would slightly affect the primal solution, which is
+    // something we want to avoid. A small inconsistency between the field
+    // computed by the primal solver and the reconstructed one may occur, when
+    // BCs depending on the flux value (e.g.  outletInlet) are used. To avoid
+    // this inconsistency activate 'storeAllBoundaries' in the storade
+    // subdictionary, although this means that all field boundaries will be
+    // stored and the correctBCs will not be called upon reconstruction.
+    // p.correctBoundaryConditions();
+
+    incoVars_.laminarTransport().correct();
+    turbulence->correct();
+
+    // Print objective values to screen and compute mean value
+    Info<< endl;
+    for (objective* obj : objectives_)
+    {
+        Info<< obj->objectiveName() << " : " << obj->J() << endl;
+        obj->accumulateJMean();
+        obj->writeInstantaneousValue();
+    }
+
+    // Average fields if necessary
+    incoVars_.computeMeanUnsteadyFields();
+
+    // Calls time.write()
+    solverControl_().writeFields();
+
+    // Print execution time
+    time.printExecutionTime(Info);
+
+    printFields();
+}
+
+
+void Foam::piso::solve()
+{
+    // Iterate
+    if (active_)
+    {
+        preLoop();
+        while (loop())
+        {
+            this->solveIter();
+        }
+        postLoop();
+    }
+}
+
+
+bool Foam::piso::loop()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    return time.loop();
+}
+
+
+void Foam::piso::restoreInitValues()
+{
+    incoVars_.restoreInitValues();
+}
+
+
+void Foam::piso::preLoop()
+{
+    // Move to the correct time, if changed by a previous primal solver
+    timeManip_.moveToPrimalStartTime();
+
+    // Get the objectives for this solver
+    if (objectives_.empty())
+    {
+        objectives_ = getObjectiveFunctions();
+    }
+
+    // Reset initial and mean fields before solving
+    restoreInitValues();
+    if (shouldResetMeanFields_)
+    {
+        incoVars_.resetMeanFields();
+    }
+
+    // Validate turbulence model fields
+    incoVars_.turbulence()->validate();
+
+    // nullify JMean for all objectives
+    // Note: we should cover the same of continuing avegaring the objective
+    // after a primal restart
+    for (objective* obj : objectives_)
+    {
+        obj->resetJMean();
+    }
+
+    // Reset primal storage
+    if (primalStorage_.valid())
+    {
+        primalStorage_().scratch();
+    }
+
+    // Print out
+    Info<< nl << "- - - - - - - - - - - - - - - - - - - - -" << endl;
+    Info<< "Solving primal equations for solver " << solverName() << endl;
+    Info<< "- - - - - - - - - - - - - - - - - - - - -" << nl << endl;
+
+    printFields();
+}
+
+
+void Foam::piso::postLoop()
+{
+    addProfiling(piso, "piso::postLoop()");
+    // Store last time instance. Redundant if a single adjoint solver is used,
+    // but necessary for more than one adjoint solvers
+    if (primalStorage_.valid())
+    {
+        // Advance time to avoid implications with the checkpointing
+        // implementation and store variables
+        timeManip_.storeTime();
+        const_cast<Time&>(mesh_.time())++;
+        primalStorage_().storeVariables();
+
+        // Restore time
+        timeManip_.restoreTime();
+
+        primalStorage_().storageMetrics();
+    }
+    // Write separators in objective files
+    for (objective* obj : objectives_)
+    {
+        obj->writeInstantaneousSeparator();
+    }
+    // Safety
+    objectives_.clear();
+
+    // Avoid writting fields if already in an outputTime iter
+    // since results will be written by the solver class either way
+    Time& time = const_cast<Time&>(mesh_.time());
+    if (!time.writeTime())
+    {
+        // Write all fields
+        time.writeNow();
+        // Write dummy turbulence fields if multiple primal solvers exist,
+        // to support seamless restarts
+        this->writeNow();
+    }
+
+    // Allow mean fields to be zeroed at the next call of preLoop
+    shouldResetMeanFields_ = true;
+
+    // Store endTimeIndex, to be retrieved later by the adjoint
+    timeManip_.storeEndTimeIndex();
+}
+
+
+void Foam::piso::postLineSearch()
+{
+    // Update averaging window for the next optimisation cycle
+    solverControl_().updateAverageStartTime();
+}
+
+
+bool Foam::piso::writeData(Ostream& os) const
+{
+    os.writeEntry("averageIter", solverControl_().averageIter());
+
+    return true;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/piso/piso.H

@@ -0,0 +1,178 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::piso
+
+Description
+    Base class for solution control classes
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef piso_H
+#define piso_H
+
+#include "incompressiblePrimalSolver.H"
+#include "PISOControl.H"
+#include "IOMRFZoneList.H"
+#include "objective.H"
+#include "unsteadyTimeManipulation.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                             Class piso Declaration
+\*---------------------------------------------------------------------------*/
+
+class piso
+:
+    public incompressiblePrimalSolver
+{
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        piso(const piso&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const piso&) = delete;
+
+
+protected:
+
+    // Protected data
+
+        //- Solver control
+        autoPtr<PISOControl> solverControl_;
+
+        //- Boolean defining if primal fields will be initialized from
+        //  the current or a costum time-step provided by the user
+        Switch shouldResetMeanFields_;
+
+        //- Reference to incompressibleVars
+        //  Used for convenience and to avoid repetitive dynamic_casts
+        //  Same as getIncoVars()
+        incompressibleVars& incoVars_;
+
+        //- MRF zones
+        IOMRFZoneList MRF_;
+
+        //- Cumulative continuity error
+        scalar cumulativeContErr_;
+
+        //- List of objectives related to this primal solver
+        List<objective*> objectives_;
+
+        //- Time manipulation, common for all primal and adjoint solvers
+        unsteadyTimeManipulation& timeManip_;
+
+
+    //- Protected Member Functions
+
+        //- Print flow fields if in debug mode
+        void printFields();
+
+        //- Allocate incompressibleVars and return reference to be used for
+        //- convenience in the rest of the class.
+        incompressibleVars& allocateVars(scalar readTime);
+
+        //- Compute Courant No
+        void CourantNo() const;
+
+        //- Compute continuity errors
+        void continuityErrors();
+
+public:
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("piso");
+
+
+    // Constructors
+
+        //- Construct from mesh and dictionary
+        piso
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const dictionary& dict,
+            Switch useCustomReadTime = false
+        );
+
+
+    //- Destructor
+    virtual ~piso() = default;
+
+
+    // Member Functions
+
+        virtual bool readDict(const dictionary& dict);
+
+        // Evolution
+
+            //- Execute one iteration of the solution algorithm
+            virtual void solveIter() override;
+
+            //- Main control loop
+            virtual void solve() override;
+
+            //- Looper (advances iters, time step)
+            virtual bool loop() override;
+
+            //- Restore initial field values if necessary
+            virtual void restoreInitValues() override;
+
+            //- Functions to be called before loop
+            virtual void preLoop() override;
+
+            //- Functions to be called after loop
+            virtual void postLoop() override;
+
+            //- Functions to be called after lineSearch has converged
+            virtual void postLineSearch() override;
+
+            //- Write average iteration
+            virtual bool writeData(Ostream& os) const override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/simple/simple.C

@@ -53,20 +53,6 @@ Foam::incompressibleVars& Foam::simple::allocateVars()
 }
 
 
-void Foam::simple::addExtraSchemes()
-{
-    if (incoVars_.useSolverNameForFields())
-    {
-        WarningInFunction
-            << "useSolverNameForFields is set to true for primalSolver "
-            << solverName() << nl << tab
-            << "Appending variable names with the solver name" << nl << tab
-            << "Please adjust the necessary entries in fvSchemes and fvSolution"
-            << nl << endl;
-    }
-}
-
-
 void Foam::simple::continuityErrors()
 {
     surfaceScalarField& phi = incoVars_.phiInst();
@@ -92,10 +78,11 @@ Foam::simple::simple
 (
     fvMesh& mesh,
     const word& managerType,
-    const dictionary& dict
+    const dictionary& dict,
+    Switch useCustomReadTime
 )
 :
-    incompressiblePrimalSolver(mesh, managerType, dict),
+    incompressiblePrimalSolver(mesh, managerType, dict, useCustomReadTime),
     solverControl_(SIMPLEControl::New(mesh, managerType, *this)),
     incoVars_(allocateVars()),
     MRF_(mesh, word(useSolverNameForFields() ? solverName() : word::null)),

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/incompressible/simple/simple.H

@@ -93,11 +93,6 @@ protected:
         //- convenience in the rest of the class.
         incompressibleVars& allocateVars();
 
-        //- In case variable names are different than the base ones,
-        //- add extra schemes and relaxation factors to the appropriate dicts
-        //  Note: Not supported for now
-        void addExtraSchemes();
-
         //- Compute continuity errors
         void continuityErrors();
 
@@ -117,7 +112,8 @@ public:
         (
             fvMesh& mesh,
             const word& managerType,
-            const dictionary& dict
+            const dictionary& dict,
+            Switch useCustomReadTime = false
         );
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/primalSolver/primalSolver.C

@@ -46,10 +46,12 @@ Foam::primalSolver::primalSolver
 (
     fvMesh& mesh,
     const word& managerType,
-    const dictionary& dict
+    const dictionary& dict,
+    Switch useCustomReadTime
 )
 :
-    solver(mesh, managerType, dict)
+    solver(mesh, managerType, dict),
+    primalStorage_(nullptr)
 {}
 
 
@@ -59,7 +61,8 @@ Foam::autoPtr<Foam::primalSolver> Foam::primalSolver::New
 (
     fvMesh& mesh,
     const word& managerType,
-    const dictionary& dict
+    const dictionary& dict,
+    Switch useCustomReadTime
 )
 {
     const word solverType(dict.get<word>("type"));
@@ -77,7 +80,11 @@ Foam::autoPtr<Foam::primalSolver> Foam::primalSolver::New
         ) << exit(FatalIOError);
     }
 
-    return autoPtr<primalSolver>(ctorPtr(mesh, managerType, dict));
+    return
+        autoPtr<primalSolver>
+        (
+            ctorPtr(mesh, managerType, dict, useCustomReadTime)
+        );
 }
 
 
@@ -94,6 +101,12 @@ bool Foam::primalSolver::readDict(const dictionary& dict)
 }
 
 
+Foam::autoPtr<Foam::primalStorage>& Foam::primalSolver::getPrimalStorage()
+{
+    return primalStorage_;
+}
+
+
 void Foam::primalSolver::correctBoundaryConditions()
 {
     // Do nothing

src/optimisation/adjointOptimisation/adjoint/solvers/primalSolvers/primalSolver/primalSolver.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -40,6 +40,7 @@ Description
 #include "fvMesh.H"
 #include "solver.H"
 #include "runTimeSelectionTables.H"
+#include "primalStorage.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -65,6 +66,16 @@ private:
         void operator=(const primalSolver&) = delete;
 
 
+protected:
+
+    // Protected Member Variables
+
+        //- Primal storage strategy
+        //  For stroring the primal history, to be later used by the
+        //  unsteady adjoint solvers
+        autoPtr<primalStorage> primalStorage_;
+
+
 public:
 
 
@@ -84,9 +95,10 @@ public:
             (
                 fvMesh& mesh,
                 const word& managerType,
-                const dictionary& dict
+                const dictionary& dict,
+                Switch useCustomReadTime
             ),
-            (mesh, managerType, dict)
+            (mesh, managerType, dict, useCustomReadTime)
         );
 
 
@@ -97,7 +109,8 @@ public:
         (
             fvMesh& mesh,
             const word& managerType,
-            const dictionary& dict
+            const dictionary& dict,
+            Switch useCustomReadTime = false
         );
 
 
@@ -108,7 +121,8 @@ public:
         (
             fvMesh& mesh,
             const word& managerType,
-            const dictionary& dict
+            const dictionary& dict,
+            Switch useCustomReadTime = false
         );
 
 
@@ -120,6 +134,9 @@ public:
 
         virtual bool readDict(const dictionary& dict);
 
+        //- Reference to the primal storage method
+        autoPtr<primalStorage>& getPrimalStorage();
+
 
         // Evolution
 

src/optimisation/adjointOptimisation/adjoint/solvers/solver/solver.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -146,6 +146,12 @@ void Foam::solver::postLoop()
 }
 
 
+void Foam::solver::postLineSearch()
+{
+    // Does nothing in the base class
+}
+
+
 void Foam::solver::updateOptTypeSource
 (
     const autoPtr<volScalarField>& optSourcePtr

src/optimisation/adjointOptimisation/adjoint/solvers/solver/solver.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -165,6 +165,9 @@ public:
             //- Functions to be called after loop
             virtual void postLoop();
 
+            //- Functions to be called after lineSearch has converged
+            virtual void postLineSearch();
+
             //- Update source term related to optimisationType
             void updateOptTypeSource
             (

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PIMPLEControl/PIMPLEControl/PIMPLEControl.C

@@ -0,0 +1,143 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "PIMPLEControl.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(PIMPLEControl, 0);
+    defineRunTimeSelectionTable(PIMPLEControl, dictionary);
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::PIMPLEControl::PIMPLEControl
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const solver& solver
+)
+:
+    solverControl(solver),
+    pimpleControl(mesh, "PIMPLE", false),
+    managerType_(managerType),
+    pRefCell_(Zero),
+    pRefValue_(Zero),
+    timeManip_
+    (
+        const_cast<unsteadyTimeManipulation&>
+        (
+            unsteadyTimeManipulation::New(mesh)
+        )
+    )
+{
+    read();
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+Foam::autoPtr<Foam::PIMPLEControl> Foam::PIMPLEControl::New
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const solver& solver
+)
+{
+    auto* ctorPtr = dictionaryConstructorTable(managerType);
+
+    if (!ctorPtr)
+    {
+        FatalErrorInLookup
+        (
+            "control",
+            managerType,
+            *dictionaryConstructorTablePtr_
+        ) << exit(FatalError);
+    }
+
+    return autoPtr<PIMPLEControl>(ctorPtr(mesh, managerType, solver));
+}
+
+
+bool Foam::PIMPLEControl::read()
+{
+    pimpleControl::read();
+    solverControl::read();
+
+    // Always store initial field values in unsteady runs
+    storeInitValues_ = true;
+
+    /*Info<< nl << algorithmName_;
+
+    if (nCorrPIMPLE_ > 1)
+    {
+        if (residualControl_.empty())
+        {
+            Info<< ": no residual control data found. "
+                << "Calculations will employ " << nCorrPIMPLE_
+                << " corrector loops" << nl;
+        }
+        else
+        {
+            Info<< ": max iterations = " << nCorrPIMPLE_ << nl;
+
+            for (const fieldData& ctrl : residualControl_)
+            {
+                Info<< "    field " << ctrl.name << token::TAB
+                    << ": relTol " << ctrl.relTol
+                    << ", tolerance " << ctrl.absTol
+                    << nl;
+            }
+        }
+    }
+    else
+    {
+        Info<< ": Operating solver in PISO mode" << nl;
+    }
+
+    Info<< endl;*/
+
+    return true;
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::PIMPLEControl::updateAverageStartTime()
+{
+    averageStartTime_ += timeManip_.span();
+    DebugInfo
+        << "Set averageStartTime to " << averageStartTime_ << endl;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PIMPLEControl/PIMPLEControl/PIMPLEControl.H

@@ -0,0 +1,185 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::PIMPLEControl
+
+Description
+    PIMPLE control class to supply convergence information/checks for
+    the PIMPLE loop.
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef PIMPLEControl_H
+#define PIMPLEControl_H
+
+#include "solverControl.H"
+#include "pimpleControl.H"
+#include "unsteadyTimeManipulation.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                        Class PIMPLEControl Declaration
+\*---------------------------------------------------------------------------*/
+
+class PIMPLEControl
+:
+    public solverControl,
+    public pimpleControl
+{
+
+protected:
+
+    // Protected Data
+
+        //- Optimisation type
+        const word& managerType_;
+
+        //- Pressure reference cell
+        label pRefCell_;
+        //
+        //- Pressure reference value
+        scalar pRefValue_;
+
+        //- Time manipulation during unsteady optimisation
+        unsteadyTimeManipulation& timeManip_;
+
+
+private:
+
+        //- No copy construct
+        PIMPLEControl(const PIMPLEControl&) = delete;
+
+        //- No copy assignment
+        void operator=(const PIMPLEControl&) = delete;
+
+
+public:
+
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("PIMPLEControl");
+
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            PIMPLEControl,
+            dictionary,
+            (
+                fvMesh& mesh,
+                const word& managerType,
+                const solver& solver
+            ),
+            (mesh, managerType, solver)
+        );
+
+
+    // Constructors
+
+        //- Construct from mesh
+        PIMPLEControl
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const solver& solver
+        );
+
+
+    //- Destructor
+    virtual ~PIMPLEControl() = default;
+
+
+    // Selectors
+
+        //- Return a reference to the selected turbulence model
+        static autoPtr<PIMPLEControl> New
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const solver& solver
+        );
+
+
+    // Member Functions
+
+        virtual bool read();
+
+        // Access
+
+            //- Return the solution dictionary
+            inline virtual const dictionary dict() const;
+
+            //- Return pressure reference cell
+            inline label& pRefCell();
+
+            //- Return pressure reference value
+            inline scalar& pRefValue();
+
+            //- Return the time span of each optimisation cycle
+            inline scalar timeSpan() const;
+
+            //- Update the start time of averaging for the next opt. cycle
+            void updateAverageStartTime();
+
+
+        // Solution control
+
+            //- Whether to call time.write() or not
+            virtual void writeFields() = 0;
+
+            //- Use averaged fields?
+            //  For solving the adjoint equations or computing sensitivities
+            //  based on averaged fields
+            inline bool useAveragedFields() const;
+
+        // Evolution
+
+            //- Loop
+            virtual bool loop() = 0;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+#include "PIMPLEControlI.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PIMPLEControl/PIMPLEControl/PIMPLEControlI.H

@@ -0,0 +1,61 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+inline const Foam::dictionary Foam::PIMPLEControl::dict() const
+{
+    return solutionDict();
+}
+
+
+inline Foam::label& Foam::PIMPLEControl::pRefCell()
+{
+    return pRefCell_;
+}
+
+
+inline Foam::scalar& Foam::PIMPLEControl::pRefValue()
+{
+    return pRefValue_;
+}
+
+
+inline Foam::scalar Foam::PIMPLEControl::timeSpan() const
+{
+    return timeManip_.span();
+}
+
+
+inline bool Foam::PIMPLEControl::useAveragedFields() const
+{
+    return false;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PIMPLEControl/optimisation/PIMPLEControlOpt.C

@@ -0,0 +1,71 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "PIMPLEControlOpt.H"
+#include "addToRunTimeSelectionTable.H"
+#include "Time.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(PIMPLEControlOpt, 0);
+    addToRunTimeSelectionTable(PIMPLEControl, PIMPLEControlOpt, dictionary);
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::PIMPLEControlOpt::PIMPLEControlOpt
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const solver& solver
+)
+:
+    PIMPLEControl(mesh, managerType, solver)
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::PIMPLEControlOpt::writeFields()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    time.write();
+    solver_.write();
+}
+
+
+bool Foam::PIMPLEControlOpt::loop()
+{
+    return pimpleControl::loop();
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PIMPLEControl/optimisation/PIMPLEControlOpt.H

@@ -0,0 +1,112 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::PIMPLEControlOpt
+
+Description
+    PIMPLE control class for single runs (i.e. not optimisation).
+    Time acts as in simpleFoam, with all solver control read through
+    optimisationDict
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef PIMPLEControlOpt_H
+#define PIMPLEControlOpt_H
+
+#include "PIMPLEControl.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                       Class PIMPLEControlOpt Declaration
+\*---------------------------------------------------------------------------*/
+
+class PIMPLEControlOpt
+:
+    public PIMPLEControl
+{
+private:
+
+        //- No copy construct
+        PIMPLEControlOpt(const PIMPLEControlOpt&) = delete;
+
+        //- No copy assignment
+        void operator=(const PIMPLEControlOpt&) = delete;
+
+
+public:
+
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("unsteadyOptimisation");
+
+
+    // Constructors
+
+        //- Construct from mesh
+        PIMPLEControlOpt
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const solver& solver
+        );
+
+
+    //- Destructor
+    virtual ~PIMPLEControlOpt() = default;
+
+
+    // Member Functions
+
+        // Solution control
+
+            //- Whether to call time.write() or not
+            virtual void writeFields();
+
+
+        // Evolution
+
+            //- Loop
+            virtual bool loop();
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PISOControl/PISOControl/PISOControl.C

@@ -0,0 +1,113 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "PISOControl.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(PISOControl, 0);
+    defineRunTimeSelectionTable(PISOControl, dictionary);
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::PISOControl::PISOControl
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const solver& solver
+)
+:
+    solverControl(solver),
+    pisoControl(mesh, "PISO"),
+    managerType_(managerType),
+    pRefCell_(Zero),
+    pRefValue_(Zero),
+    timeManip_
+    (
+        const_cast<unsteadyTimeManipulation&>
+        (
+            unsteadyTimeManipulation::New(mesh)
+        )
+    )
+{
+    read();
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+Foam::autoPtr<Foam::PISOControl> Foam::PISOControl::New
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const solver& solver
+)
+{
+    auto* ctorPtr = dictionaryConstructorTable(managerType);
+
+    if (!ctorPtr)
+    {
+        FatalErrorInLookup
+        (
+            "control",
+            managerType,
+            *dictionaryConstructorTablePtr_
+        ) << exit(FatalError);
+    }
+
+    return autoPtr<PISOControl>(ctorPtr(mesh, managerType, solver));
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+bool Foam::PISOControl::read()
+{
+    pisoControl::read();
+    solverControl::read();
+
+    // Always store initial field values in unsteady runs
+    storeInitValues_ = true;
+
+    return true;
+}
+
+
+void Foam::PISOControl::updateAverageStartTime()
+{
+    averageStartTime_ += timeManip_.span();
+    DebugInfo
+        << "Set averageStartTime to " << averageStartTime_ << endl;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PISOControl/PISOControl/PISOControl.H

@@ -0,0 +1,186 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::PISOControl
+
+Description
+    PISO control class to supply convergence information/checks for
+    the PISO loop.
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef PISOControl_H
+#define PISOControl_H
+
+#include "solverControl.H"
+#include "pisoControl.H"
+#include "unsteadyTimeManipulation.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                         Class PISOControl Declaration
+\*---------------------------------------------------------------------------*/
+
+class PISOControl
+:
+    public solverControl,
+    public pisoControl
+{
+
+protected:
+
+    // Protected Data
+
+        //- Optimisation type
+        const word& managerType_;
+
+        //- Pressure reference cell
+        label pRefCell_;
+        //
+        //- Pressure reference value
+        scalar pRefValue_;
+
+        //- Time manipulation during unsteady optimisation
+        unsteadyTimeManipulation& timeManip_;
+
+
+private:
+
+        //- No copy construct
+        PISOControl(const PISOControl&) = delete;
+
+        //- No copy assignment
+        void operator=(const PISOControl&) = delete;
+
+
+public:
+
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("PISOControl");
+
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            PISOControl,
+            dictionary,
+            (
+                fvMesh& mesh,
+                const word& managerType,
+                const solver& solver
+            ),
+            (mesh, managerType, solver)
+        );
+
+
+    // Constructors
+
+        //- Construct from mesh
+        PISOControl
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const solver& solver
+        );
+
+
+    //- Destructor
+    virtual ~PISOControl() = default;
+
+
+    // Selectors
+
+        //- Return a reference to the selected turbulence model
+        static autoPtr<PISOControl> New
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const solver& solver
+        );
+
+
+    // Member Functions
+
+        virtual bool read();
+
+        // Access
+
+            //- Return the solution dictionary
+            inline virtual const dictionary dict() const;
+
+            //- Return pressure reference cell
+            inline label& pRefCell();
+
+            //- Return pressure reference value
+            inline scalar& pRefValue();
+
+            //- Return the time span of each optimisation cycle
+            inline scalar timeSpan() const;
+
+            //- Update the start time of averaging for the next opt. cycle
+            void updateAverageStartTime();
+
+
+        // Solution control
+
+            //- Whether to call time.write() or not
+            virtual void writeFields() = 0;
+
+            //- Use averaged fields?
+            //  For solving the adjoint equations or computing sensitivities
+            //  based on averaged fields
+            inline bool useAveragedFields() const;
+
+
+        // Evolution
+
+            //- Loop
+            virtual bool loop() = 0;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+#include "PISOControlI.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PISOControl/PISOControl/PISOControlI.H

@@ -0,0 +1,62 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+inline const Foam::dictionary Foam::PISOControl::dict() const
+{
+    return solutionDict();
+}
+
+
+inline Foam::label& Foam::PISOControl::pRefCell()
+{
+    return pRefCell_;
+}
+
+
+inline Foam::scalar& Foam::PISOControl::pRefValue()
+{
+    return pRefValue_;
+}
+
+
+inline Foam::scalar Foam::PISOControl::timeSpan() const
+{
+    return timeManip_.span();
+}
+
+
+inline bool Foam::PISOControl::useAveragedFields() const
+{
+    return false;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PISOControl/optimisation/PISOControlOpt.C

@@ -0,0 +1,71 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "PISOControlOpt.H"
+#include "addToRunTimeSelectionTable.H"
+#include "Time.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(PISOControlOpt, 0);
+    addToRunTimeSelectionTable(PISOControl, PISOControlOpt, dictionary);
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::PISOControlOpt::PISOControlOpt
+(
+    fvMesh& mesh,
+    const word& managerType,
+    const solver& solver
+)
+:
+    PISOControl(mesh, managerType, solver)
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::PISOControlOpt::writeFields()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    time.write();
+    solver_.write();
+}
+
+
+bool Foam::PISOControlOpt::loop()
+{
+    return pisoControl::loop();
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/PISOControl/optimisation/PISOControlOpt.H

@@ -0,0 +1,112 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::PISOControlOpt
+
+Description
+    PISO control class for single runs (i.e. not optimisation).
+    Time acts as in simpleFoam, with all solver control read through
+    optimisationDict
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef PISOControlOpt_H
+#define PISOControlOpt_H
+
+#include "PISOControl.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                        Class PISOControlOpt Declaration
+\*---------------------------------------------------------------------------*/
+
+class PISOControlOpt
+:
+    public PISOControl
+{
+private:
+
+        //- No copy construct
+        PISOControlOpt(const PISOControlOpt&) = delete;
+
+        //- No copy assignment
+        void operator=(const PISOControlOpt&) = delete;
+
+
+public:
+
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("unsteadyOptimisation");
+
+
+    // Constructors
+
+        //- Construct from mesh
+        PISOControlOpt
+        (
+            fvMesh& mesh,
+            const word& managerType,
+            const solver& solver
+        );
+
+
+    //- Destructor
+    virtual ~PISOControlOpt() = default;
+
+
+    // Member Functions
+
+        // Solution control
+
+            //- Whether to call time.write() or not
+            virtual void writeFields();
+
+
+        // Evolution
+
+            //- Loop
+            virtual bool loop();
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/SIMPLEControl/optimisation/SIMPLEControlOpt.C

@@ -36,7 +36,7 @@ License
 namespace Foam
 {
     defineTypeNameAndDebug(SIMPLEControlOpt, 1);
-    addToRunTimeSelectionTable( SIMPLEControl, SIMPLEControlOpt, dictionary);
+    addToRunTimeSelectionTable(SIMPLEControl, SIMPLEControlOpt, dictionary);
 }
 
 // * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/solverControl/solverControl.C

@@ -46,6 +46,7 @@ bool Foam::solverControl::read()
     // Manage averaging
     dictionary averagingDict = solutionDict().subOrEmptyDict("averaging");
     averageStartIter_ = averagingDict.getOrDefault<label>("startIter", -1);
+    averageStartTime_ = averagingDict.getOrDefault<scalar>("startTime", -1);
 
     return true;
 }
@@ -60,6 +61,7 @@ Foam::solverControl::solverControl(const solver& solver)
     iter_(0),
     averageIter_(solver.getOrDefault<label>("averageIter", 0)),
     averageStartIter_(-1),
+    averageStartTime_(-1),
     // Non run-time modifiable options read in the constructor only
     storeInitValues_
     (

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/solverControl/solverControl.H

@@ -76,6 +76,9 @@ protected:
             //- Averaging start index
             label averageStartIter_;
 
+            //- Averaging start time
+            scalar averageStartTime_;
+
             // Non run-time modifiable entries
 
                 //- Whether to re-initialize the solution based on the initial
@@ -151,17 +154,30 @@ public:
             //- Return iteration index
             inline label averageStartIter() const;
 
+            //- Return averaging start time reference for unsteady runs
+            inline scalar& averageStartTime();
+
+            //- Return const averaging start time reference for unsteady runs
+            inline scalar averageStartTime() const;
+
             //- Whether or not to add fields of the current iteration to the
             //- average fields
             inline bool doAverageIter() const;
 
+            //- Whether or not to add fields of the current time to the
+            //- average fields
+            inline bool doAverageTime() const;
+
             //- Use averaged fields?
             //- For solving the adjoint equations or computing sensitivities
             //- based on averaged fields
-            inline bool useAveragedFields() const;
+            virtual inline bool useAveragedFields() const;
 
             //- Whether averaging is enabled or not
             inline bool average() const;
+
+        //- Return reference to the underlaying solver
+        inline const solver& getSolver() const;
 };
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/solverControl/solverControl/solverControlI.H

@@ -78,6 +78,18 @@ inline Foam::label Foam::solverControl::averageStartIter() const
 }
 
 
+inline Foam::scalar& Foam::solverControl::averageStartTime()
+{
+    return averageStartTime_;
+}
+
+
+inline Foam::scalar Foam::solverControl::averageStartTime() const
+{
+    return averageStartTime_;
+}
+
+
 inline bool Foam::solverControl::doAverageIter() const
 {
     if (average_ && iter_ >= averageStartIter_)
@@ -91,6 +103,19 @@ inline bool Foam::solverControl::doAverageIter() const
 }
 
 
+inline bool Foam::solverControl::doAverageTime() const
+{
+    if (average_ && solver_.mesh().time().value() >= averageStartTime_)
+    {
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 inline bool Foam::solverControl::useAveragedFields() const
 {
     if (average_ && averageIter_)
@@ -110,4 +135,10 @@ inline bool Foam::solverControl::average() const
 }
 
 
+inline const Foam::solver& Foam::solverControl::getSolver() const
+{
+    return solver_;
+}
+
+
 // ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/checkPoint/checkPoint.C

@@ -0,0 +1,145 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "checkPoint.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+defineTypeNameAndDebug(checkPoint, 0);
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+checkPoint::checkPoint
+(
+    storageParameters& storageParams
+)
+:
+    vars_(),
+    storageParams_(storageParams),
+    mesh_(storageParams.mesh()),
+    storageMetrics_(),
+    deltaT_(0.),
+    active_(false),
+    placeHolder_(true),
+    a_(-1),
+    checkPointLevel_(-1),
+    checkPointTimeIndex_(-1),
+    checkPointTime_(-1.)
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void checkPoint::retrieve()
+{
+    if (!vars_)
+    {
+        FatalErrorInFunction
+            << "Trying to retrieve solution at t = "
+            << storageParams_.mesh().time().value()
+            << " from checkPoint with t = "
+            << checkPointTime_ << nl
+            << "but no storage has been allocated." << nl
+            << "placeHolder checkPoint? " << placeHolder_ << endl
+            << exit(FatalError);
+    }
+    vars_().decompress();
+}
+
+
+void checkPoint::setPlaceHolder(Switch newLevel)
+{
+    deltaT_ = storageParams_.mesh().time().deltaTValue();
+    active_ = true;
+    placeHolder_ = true;
+    a_ = 0;
+    checkPointTimeIndex_ = storageParams_.mesh().time().timeIndex();
+    checkPointTime_ = storageParams_.mesh().time().value();
+    if (newLevel)
+    {
+        checkPointLevel_ += 1;
+    }
+    else
+    {
+        checkPointLevel_ = 0;
+    }
+    // Clear the  previously allocated storage
+    vars_.clear();
+    storageMetrics_.clear();
+}
+
+
+void checkPoint::store(incompressibleVars& vs, const label a)
+{
+    placeHolder_ = false;
+    a_ = a;
+    vars_.reset(new fullIncompressibleVars(vs, storageParams_, a_));
+    vars_().compress();
+    storageMetrics_ = vars_().storageMetrics();
+}
+
+
+void checkPoint::empty()
+{
+    active_ = false;
+    placeHolder_ = true;
+    checkPointTimeIndex_ = -1;
+    checkPointTime_ = -1;
+    checkPointLevel_ = -1;
+    a_ = -1;
+    vars_.clear();
+    storageMetrics_.clear();
+}
+
+
+void checkPoint::resetToPlaceHolder()
+{
+    placeHolder_ = true;
+    a_ = 0;
+    vars_.clear();
+    storageMetrics_.clear();
+}
+
+
+const scalarList& checkPoint::storageMetrics() const
+{
+    return storageMetrics_;
+}
+
+
+// ************************************************************************* //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/checkPoint/checkPoint.H

@@ -0,0 +1,217 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    checkPoint
+
+Description
+
+SourceFiles
+    checkPoint.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef checkPoint_H
+#define checkPoint_H
+
+#include "fullIncompressibleVars.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                          Class checkPoint Declaration
+\*---------------------------------------------------------------------------*/
+
+class checkPoint
+{
+protected:
+
+    // Protected data
+
+        //- Variables held by this checkPoint
+        autoPtr<fullIncompressibleVars> vars_;
+
+        storageParameters& storageParams_;
+
+        const fvMesh& mesh_;
+
+        scalarList storageMetrics_;
+
+        //- deltaT corresponding to the time-step this checkPoint holds
+        scalar deltaT_;
+
+        //- Whether this checkPoint is active
+        Switch active_;
+
+        //- Whether this checkPoint is a placeHolder
+        Switch placeHolder_;
+
+        //- schedule with size equal to nTimeSteps containing the number of
+        //- time-solution that must be stored at the checkPoint:
+        //  -1: inactive checkPoint     0: placeholder checkPoint;
+        //   1: single checkPoint       2: double checkPoint
+        label a_;
+
+        label checkPointLevel_;
+
+        label checkPointTimeIndex_;
+
+        scalar checkPointTime_;
+
+
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        checkPoint(const checkPoint&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const checkPoint&) = delete;
+
+public:
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("checkPoint");
+
+    // Constructors
+
+        checkPoint(storageParameters& storageParams);
+
+
+    //- Destructor
+    virtual ~checkPoint() = default;
+
+
+    // Access functions
+
+        inline scalar deltaT() const
+        {
+            return deltaT_;
+        }
+
+        inline scalar& deltaT()
+        {
+            return deltaT_;
+        }
+
+        inline Switch active() const
+        {
+            return active_;
+        }
+
+        inline Switch& active()
+        {
+            return active_;
+        }
+
+        inline const Switch& placeHolder() const
+        {
+            return placeHolder_;
+        }
+
+        inline Switch& placeHolder()
+        {
+            return placeHolder_;
+        }
+
+        inline label a() const
+        {
+            return a_;
+        }
+
+        inline label& a()
+        {
+            return a_;
+        }
+
+        inline label level() const
+        {
+            return checkPointLevel_;
+        }
+
+        inline label& level()
+        {
+            return checkPointLevel_;
+        }
+
+        inline label timeIndex() const
+        {
+            return checkPointTimeIndex_;
+        }
+
+        inline label& timeIndex()
+        {
+            return checkPointTimeIndex_;
+        }
+
+        inline scalar timeValue() const
+        {
+            return checkPointTime_;
+        }
+
+        inline scalar& timeValue()
+        {
+            return checkPointTime_;
+        }
+
+
+    // Member functions
+
+        //- Function to decompress the incompressible vars and update the
+        //- solver fields with the decompressed ones
+        void retrieve();
+
+        void setPlaceHolder(Switch newLevel);
+
+        //- store function must be called after setPlaceHolder.
+        void store(incompressibleVars& vs, const label a = 2);
+
+        //- Clear the chekpoint memory and reset its properties
+        void empty();
+
+        //- Clear the storage of the checkpoint and make it a placeHolder
+        //- checkpoint
+        void resetToPlaceHolder();
+
+        const scalarList& storageMetrics() const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/compressedIncompressible/compressedIncompressibleVars/compressedIncompressibleVars.C

@@ -0,0 +1,371 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "compressedIncompressibleVars.H"
+#include "createZeroField.H"
+#include "IOmanip.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+defineTypeNameAndDebug(compressedIncompressibleVars, 0);
+defineRunTimeSelectionTable(compressedIncompressibleVars, dictionary);
+
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void compressedIncompressibleVars::writeLog
+(
+    const word& name
+) const
+{
+    const scalar& initialSize = storageMetrics_[0];
+    const scalar& uncompressedRoughSize = storageMetrics_[1];
+    const scalar& uncompressedSize = storageMetrics_[2];
+    const scalar& compressedSize = storageMetrics_[3];
+    if (!initialSize || !uncompressedSize || !uncompressedRoughSize)
+    {
+        FatalErrorInFunction
+            << "initialSize, uncompressedRoughSize or uncompressedSize is Zero"
+            << endl
+            << exit(FatalError);
+    }
+    if (!compressedSize)
+    {
+        FatalErrorInFunction
+            << "compressedSize is Zero" << endl
+            << exit(FatalError);
+    }
+    unsigned int width = 6;//IOstream::defaultPrecision();
+    Info<< setprecision(width);
+    Info<< name << tab << "pure algorithm's CR = "
+        << uncompressedSize/compressedSize << endl;
+    if (debug)
+    {
+        Info<< name << ": Initial Size             = "
+            << initialSize*1.e-6 << " Mb" << nl
+            << name << ": Initial Size saved       = "
+            << uncompressedRoughSize*1.e-6 << " Mb" << nl
+            << name << ": Uncompressed Size        = "
+            << uncompressedSize*1.e-6 << " Mb" << nl
+            << name << ": Compressed Size          = "
+            << compressedSize*1.e-6 << " Mb" << endl;
+        if (name == "All")
+        {
+            Info<< name
+                << ": Data Increase due to data manipulation before compression = "
+                << (uncompressedSize-uncompressedRoughSize)/uncompressedRoughSize*100. << "%"
+                << endl;
+        }
+        Info<< name << ": (%) Data Reduction       = "
+            << (uncompressedSize-compressedSize)/uncompressedSize*100. << "%"
+            << endl;
+    }
+    Info<< setprecision(IOstream::defaultPrecision());
+    if (name == "All")
+    {
+        Info << endl;
+    }
+}
+
+
+void compressedIncompressibleVars::write(const label i)
+{
+    if (Pstream::master())
+    {
+        if (storageFilePtr_.empty())
+        {
+            setStorageFilesPtr();
+        }
+        const scalar initialSize = storageMetrics_[0];
+        const scalar uncompressedRoughSize = storageMetrics_[1];
+        const scalar uncompressedSize = storageMetrics_[2];
+        const scalar compressedSize = storageMetrics_[3];
+
+        unsigned int width = IOstream::defaultPrecision() + 6;
+        storageFilePtr_[i]
+            << setprecision(6) << setw(8) << mesh_.time().value() << tab
+            << setprecision(IOstream::defaultPrecision())
+            << setw(width) << uncompressedSize/compressedSize << tab
+            << setw(width) << (uncompressedSize-compressedSize)/uncompressedSize*100. << tab
+            << setw(width) << initialSize*1.e-6 << tab
+            << setw(width) << uncompressedRoughSize*1.e-6 << tab
+            << setw(width) << compressedSize*1.e-6 << endl;
+        storageFilePtr_.clear();
+    }
+}
+
+
+void compressedIncompressibleVars::setFields()
+{
+    incompressibleVars& v = incoVars_;
+    p_.reset(compressedVolScalarField::New(v.pInst(), storageParams_, 0, k_));
+    phi_.reset
+    (
+        compressedSurfaceScalarField::New(v.phiInst(), storageParams_, 1, k_)
+    );
+    U_.reset(compressedVolVectorField::New(v.UInst(), storageParams_, 2, k_));
+    incompressible::RASModelVariables& rasVars = v.RASModelVariables()();
+    if (rasVars.hasTMVar1())
+    {
+        RASModelVars_.append
+        (
+            compressedVolScalarField::New
+                (rasVars.TMVar1Inst(), storageParams_, 3, k_)
+        );
+    }
+    if (rasVars.hasTMVar2())
+    {
+        RASModelVars_.append
+        (
+            compressedVolScalarField::New
+                (rasVars.TMVar2Inst(), storageParams_, 4, k_)
+        );
+    }
+}
+
+
+void compressedIncompressibleVars::makeFolder()
+{
+    if (Pstream::master())
+    {
+        storageFolder_ = mesh_.time().globalPath()/"optimisation"/"storage";
+        if (!isDir(storageFolder_))
+        {
+            mkDir(storageFolder_);
+            WarningInFunction
+                << "The folder storing the compression metrics should have "
+                << "been already set."
+                << nl
+                << "Possible error in: compressedFullStorage::makeFolder()."
+                << "Setting folder anyway." << nl
+                << endl;
+        }
+    }
+}
+
+
+void compressedIncompressibleVars::setStorageFilesPtr()
+{
+    storageFilePtr_.setSize(7);
+    label Ic = -1;
+    names_.setSize(7, "undefined");
+    names_[++Ic] = "AllFields" + solverName();
+    names_[++Ic] = incoVars_.pInst().name();
+    names_[++Ic] = incoVars_.phiInst().name();
+    names_[++Ic] = incoVars_.UInst().name();
+    incompressible::RASModelVariables& rasVars =
+        incoVars_.RASModelVariables()();
+    forAll(RASModelVars_, iPtr)
+    {
+        if (iPtr == 0)
+        {
+            names_[++Ic] = rasVars.TMVar1Inst().name();
+        }
+        else if (iPtr == 1)
+        {
+            names_[++Ic] = rasVars.TMVar2Inst().name();
+        }
+    }
+    for (label i = 0; i <= Ic; i++)
+    {
+        fileName filePath = storageFolder_/names_[i];
+        if (!isFile(filePath))
+        {
+            storageFilePtr_.set
+            (
+                i, new OFstream(filePath)
+            );
+            unsigned int width = IOstream::defaultPrecision() + 6;
+            storageFilePtr_[i]
+                << setw(8) << "# Time" << tab
+                << setw(width) << "algorithm's CR" << tab
+                << setw(width) << "(%) Reduction" << tab
+                << setw(width) << "Initial Size (Mb)" << tab
+                << setw(width) << "Uncompressed Size (Mb)" << tab
+                << setw(width) << "Compressed Size (Mb)" << endl;
+        }
+        else
+        {
+            storageFilePtr_.set
+            (
+                i,
+                new OFstream
+                (
+                    filePath,
+                    IOstream::ASCII,
+                    IOstream::currentVersion,
+                    IOstream::UNCOMPRESSED,
+                    true
+                )
+            );
+        }
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+compressedIncompressibleVars::compressedIncompressibleVars
+(
+    incompressibleVars& vs,
+    storageParameters& storageParams
+)
+:
+    variablesSet
+    (
+        vs.mesh(),
+        vs.solverControlReference().solverDict()
+    ),
+    incoVars_(vs),
+    solverControl_(vs.solverControlReference()),
+    storageParams_(storageParams),
+    k_(0),
+    kCopy_(k_),
+    p_(nullptr),
+    phi_(nullptr),
+    U_(nullptr),
+    RASModelVars_(),
+    timeIndex_(mesh_.time().timeIndex()),
+    timeValue_(mesh_.time().value()),
+    storageMetrics_(),
+    names_(7, "undefined"),
+    storageFilePtr_()
+{
+    setFields();
+    makeFolder();
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+autoPtr<compressedIncompressibleVars> compressedIncompressibleVars::New
+(
+    incompressibleVars& vs,
+    storageParameters& storageParams
+)
+{
+    const word type = storageParams.algorithm() + "IncompressibleVars";
+    DebugInfo
+        << "compressedIncompressibleVars type for the primal fields: " << type
+        << endl;
+
+    auto cstrIter = dictionaryConstructorTablePtr_->cfind(type);
+
+    if (!cstrIter.found())
+    {
+        FatalErrorInFunction
+            << "Unknown compressedIncompressibleVars type " << type << nl << nl
+            << "Valid compressedIncompressibleVars types are :" << nl
+            << dictionaryConstructorTablePtr_->sortedToc()
+            << exit(FatalIOError);
+    }
+
+    return autoPtr<compressedIncompressibleVars>
+        (cstrIter()(vs, storageParams));
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void compressedIncompressibleVars::calculateStorageMetrics()
+{
+    storageMetrics_.setSize(p_().storageMetrics().size());
+    label i = 0;
+    if (!storageParams_.timing())
+    {
+        calculateAndWrite(p_(), incoVars_.pInst().name(), i);
+        calculateAndWrite(phi_(), incoVars_.phiInst().name(), i);
+        calculateAndWrite(U_(), incoVars_.UInst().name(), i);
+        incompressible::RASModelVariables& rasVars =
+            incoVars_.RASModelVariables()();
+        if (rasVars.hasTMVar1())
+        {
+            calculateAndWrite(RASModelVars_[0], rasVars.TMVar1Inst().name(), i);
+        }
+        if (rasVars.hasTMVar2())
+        {
+            calculateAndWrite(RASModelVars_[1], rasVars.TMVar2Inst().name(), i);
+        }
+    }
+    storageMetrics_ =
+        p_().storageMetrics()
+      + phi_().storageMetrics()
+      + U_().storageMetrics();
+
+    forAll(RASModelVars_, iPtr)
+    {
+        storageMetrics_ =
+            storageMetrics_ + RASModelVars_[iPtr].storageMetrics();
+    }
+    if (!storageParams_.timing())
+    {
+        write(0);
+        writeLog("All");
+    }
+    storageFilePtr_.clear();
+    names_.clear();
+}
+
+
+void compressedIncompressibleVars::compress()
+{
+    NotImplemented
+}
+
+
+void compressedIncompressibleVars::decompress
+(
+    incompressibleVars& vars
+)
+{
+    NotImplemented
+}
+
+
+void compressedIncompressibleVars::decompress()
+{
+    this->decompress(incoVars_);
+}
+
+
+const scalarList& compressedIncompressibleVars::storageMetrics() const
+{
+    return storageMetrics_;
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/compressedIncompressible/compressedIncompressibleVars/compressedIncompressibleVars.H

@@ -0,0 +1,228 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::compressedIncompressibleVars
+
+Description
+    Base class for solution control classes
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef compressedIncompressibleVars_H
+#define compressedIncompressibleVars_H
+
+#include "incompressibleVars.H"
+#include "compressedGeometricFields.H"
+#include "storageParameters.H"
+#include "OFstream.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                 Class compressedIncompressibleVars Declaration
+\*---------------------------------------------------------------------------*/
+
+class compressedIncompressibleVars
+:
+    public variablesSet
+{
+protected:
+
+    // Protected data
+
+        //- Vars seen by the solver
+        incompressibleVars& incoVars_;
+
+        //- Solver control related to the base variables
+        const solverControl& solverControl_;
+
+        storageParameters& storageParams_;
+
+        //- Current S/N of the time-step that is compressed in the present
+        //- object.
+        //  Useful when more than one time-steps are compressed
+        //  in the same compressedIncompressibleVars (e.g. iPGD algorithm)
+        label k_;
+
+        label kCopy_;
+
+        //- Compressed fields including turbulence
+        autoPtr<compressedVolScalarField> p_;
+        autoPtr<compressedSurfaceScalarField> phi_;
+        autoPtr<compressedVolVectorField> U_;
+        PtrList<compressedVolScalarField> RASModelVars_;
+
+        //- Time value and index
+        label timeIndex_;
+
+        scalar timeValue_;
+
+        //- List that holds the compression metrics (initial size, compressed
+        //- size if compression is applied, etc) for all fields of the current
+        //- time step.
+        scalarList storageMetrics_;
+
+        //- Variables used for writing the compression metrics
+        fileName storageFolder_;
+        wordList names_;
+        mutable PtrList<OFstream> storageFilePtr_;
+
+
+    // Protected Member Functions
+
+        //- Set compressed fields including turbulence
+        void setFields();
+
+        //- Calculate and write compression metrics for a
+        //- compressedGeometricField
+        template<class Type, template<class> class PatchField, class GeoMesh>
+        void calculateAndWrite
+        (
+            const compressedGeometricField<Type, PatchField, GeoMesh>& compField,
+            const word& name,
+            label& i
+        );
+
+        //- Function to write the compressed size, the compression ratio, etc.
+        virtual void writeLog(const word&) const;
+
+        //- Function to write compression metrics to file
+        virtual void write(const label);
+
+        //- Set folder
+        void makeFolder();
+
+        //- Set File to store compression metrics
+        virtual void setStorageFilesPtr();
+
+
+public:
+
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("compressedIncompressibleVars");
+
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            compressedIncompressibleVars,
+            dictionary,
+            (
+                incompressibleVars& vs,
+                storageParameters& storageParams
+            ),
+            (vs, storageParams)
+        );
+
+
+    // Constructors
+
+        compressedIncompressibleVars
+        (
+            incompressibleVars& vs,
+            storageParameters& storageParams
+        );
+
+
+    // Selectors
+
+        //- Return a reference to the selected turbulence model
+        static autoPtr<compressedIncompressibleVars> New
+        (
+            incompressibleVars& vs,
+            storageParameters& storageParams
+        );
+
+
+    //- Destructor
+    virtual ~compressedIncompressibleVars() = default;
+
+
+    // Member Functions
+
+        inline label timeIndex() const
+        {
+            return timeIndex_;
+        }
+
+        inline label& timeIndex()
+        {
+            return timeIndex_;
+        }
+
+        inline scalar timeValue() const
+        {
+            return timeValue_;
+        }
+
+        inline scalar& timeValue()
+        {
+            return timeValue_;
+        }
+
+        //- Function to calculate and write the compression metrics
+        virtual void calculateStorageMetrics();
+
+        virtual void compress();
+
+        virtual void decompress
+        (
+            incompressibleVars& vars
+        );
+
+        void decompress();
+
+        //- Function to return the compression metrics (initial size,
+        //- compressed size if compression is applied, etc)
+        virtual const scalarList& storageMetrics() const override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "compressedIncompressibleVarsTemplates.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/compressedIncompressible/compressedIncompressibleVars/compressedIncompressibleVarsTemplates.C

@@ -0,0 +1,49 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2019 PCOpt/NTUA
+    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2019 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void Foam::compressedIncompressibleVars::calculateAndWrite
+(
+    const compressedGeometricField<Type, PatchField, GeoMesh>& compField,
+    const word& name,
+    label& i
+)
+{
+    forAll(storageMetrics_, Ic)
+    {
+        storageMetrics_[Ic] = compField.storageMetrics()[Ic];
+    }
+    write(++i);
+    writeLog(name);
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/compressedIncompressible/fullIncompressibleVars/fullIncompressibleVars.C

@@ -0,0 +1,215 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "fullIncompressibleVars.H"
+#include "IOmanip.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+defineTypeNameAndDebug(fullIncompressibleVars, 0);
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void fullIncompressibleVars::calculateStorageMetrics()
+{
+    storageMetrics_.setSize(p_().storageMetrics().size(), Zero);
+    label i = 0;
+    if ( !storageParams_.timing() )
+    {
+        this->calculateAndWrite(p_(), pOld_, incoVars_.pInst().name(), i);
+        this->calculateAndWrite(phi_(), phiOld_, incoVars_.phiInst().name(), i);
+        this->calculateAndWrite(U_(), UOld_, incoVars_.UInst().name(), i);
+        incompressible::RASModelVariables& rasVars =
+            incoVars_.RASModelVariables()();
+        if (rasVars.hasTMVar1())
+        {
+            this->calculateAndWrite
+                (RASModelVars_[0], TMVar1Old_, rasVars.TMVar1Inst().name(), i);
+        }
+        if (rasVars.hasTMVar2())
+        {
+            this->calculateAndWrite
+                (RASModelVars_[1], TMVar2Old_, rasVars.TMVar2Inst().name(), i);
+        }
+        storageMetrics_ = Zero;
+    }
+    addStorageMetricsContribution(p_(), pOld_);
+    addStorageMetricsContribution(phi_(), phiOld_);
+    addStorageMetricsContribution(U_(), UOld_);
+    incompressible::RASModelVariables& rasVars =
+        incoVars_.RASModelVariables()();
+    if (rasVars.hasTMVar1())
+    {
+        addStorageMetricsContribution(RASModelVars_[0], TMVar1Old_);
+    }
+    if (rasVars.hasTMVar2())
+    {
+        addStorageMetricsContribution(RASModelVars_[1], TMVar2Old_);
+    }
+    if (!storageParams_.timing())
+    {
+        write(0);
+        writeLog("All");
+    }
+    names_.clear();
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+fullIncompressibleVars::fullIncompressibleVars
+(
+    incompressibleVars& vs,
+    storageParameters& storageParams,
+    label a
+)
+:
+    compressedIncompressibleVars(vs, storageParams),
+    a_(a),
+    pOld_(),
+    phiOld_(),
+    UOld_(),
+    TMVar1Old_(),
+    TMVar2Old_()
+{
+    if (a_ < 1)
+    {
+        FatalErrorInFunction
+            << "Total number 'a' of time-solutions to be stored must be >= 1."
+            << nl
+            << "Object constructed with (a = " << a_ << ")"
+            << endl
+            << exit(FatalError);
+    }
+    storeOldTimes(incoVars_.pInst(), pOld_, 0);
+    storeOldTimes(incoVars_.phiInst(), phiOld_, 1);
+    storeOldTimes(incoVars_.UInst(), UOld_, 2);
+    incompressible::RASModelVariables& rasVars =
+        incoVars_.RASModelVariables()();
+    if (rasVars.hasTMVar1())
+    {
+        storeOldTimes(rasVars.TMVar1Inst(), TMVar1Old_, 3);
+    }
+    if (rasVars.hasTMVar2())
+    {
+        storeOldTimes(rasVars.TMVar2Inst(), TMVar2Old_, 4);
+    }
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void fullIncompressibleVars::compress()
+{
+    //scalar startTime = mesh_.time().elapsedCpuTime();
+    p_().compress();
+    forAll(pOld_, iPtr)
+    {
+        pOld_[iPtr].compress();
+    }
+    phi_().compress();
+    forAll(phiOld_, iPtr)
+    {
+        phiOld_[iPtr].compress();
+    }
+    U_().compress();
+    forAll(UOld_, iPtr)
+    {
+        UOld_[iPtr].compress();
+    }
+    incompressible::RASModelVariables& rasVars =
+        incoVars_.RASModelVariables()();
+    if (rasVars.hasTMVar1())
+    {
+        RASModelVars_[0].compress();
+        forAll(TMVar1Old_, iPtr)
+        {
+            TMVar1Old_[iPtr].compress();
+        }
+    }
+    if (rasVars.hasTMVar2())
+    {
+        RASModelVars_[1].compress();
+        forAll(TMVar2Old_, iPtr)
+        {
+            TMVar2Old_[iPtr].compress();
+        }
+    }
+    //scalar endTime = mesh_.time().elapsedCpuTime();
+    calculateStorageMetrics();
+}
+
+
+void fullIncompressibleVars::decompress
+(
+    incompressibleVars& vars
+)
+{
+    // Phi must be retrieved first, since the BCs of p and U might depend on
+    // flux
+    decompressAll(vars.phiInst(), phi_(), phiOld_);
+    DebugInfo
+        << "DEBUG: phi field retrieved" << endl;
+    decompressAll(vars.pInst(), p_(), pOld_);
+    DebugInfo
+        << "DEBUG: p field retrieved" << endl;
+    decompressAll(vars.UInst(), U_(), UOld_);
+    DebugInfo
+        << "DEBUG: U field retrieved" << endl;
+    incompressible::RASModelVariables& rasVars = vars.RASModelVariables()();
+    if (rasVars.hasTMVar1())
+    {
+        decompressAll(rasVars.TMVar1Inst(), RASModelVars_[0], TMVar1Old_);
+        DebugInfo
+            << "DEBUG: 1st turbulence model field retrieved" << endl;
+    }
+    if (rasVars.hasTMVar2())
+    {
+        decompressAll(rasVars.TMVar2Inst(), RASModelVars_[1], TMVar2Old_);
+        DebugInfo
+            << "DEBUG: 2nd turbulence model field retrieved" << endl;
+    }
+}
+
+
+void fullIncompressibleVars::decompress()
+{
+    this->decompress(incoVars_);
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/compressedIncompressible/fullIncompressibleVars/fullIncompressibleVars.H

@@ -0,0 +1,190 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::fullIncompressibleVars
+
+Description
+    Base class storing the current and the oldTime primal variables instances
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef fullIncompressibleVars_H
+#define fullIncompressibleVars_H
+
+#include "compressedIncompressibleVars.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                    Class fullIncompressibleVars Declaration
+\*---------------------------------------------------------------------------*/
+
+class fullIncompressibleVars
+:
+    public compressedIncompressibleVars
+{
+protected:
+
+    // Protected data
+
+        //- Total number of time solutions to be stored for each time instance.
+        //  E.g. for (a=1) only the solution at the current time-step will be
+        //  stored, for (a=2) the solution at the current and the previous
+        //  tim-step will be stored.
+        label a_;
+
+        //- PtrLists containing the oldTimes of all primal fields.
+        //  The fields of the current time-step are stored upon construction of
+        //  the compressedGeometricField class.
+        PtrList<compressedVolScalarField> pOld_;
+        PtrList<compressedSurfaceScalarField> phiOld_;
+        PtrList<compressedVolVectorField> UOld_;
+        PtrList<compressedVolScalarField> TMVar1Old_;
+        PtrList<compressedVolScalarField> TMVar2Old_;
+
+
+    // Protected Member Functions
+
+        //- Store oldTimes (if any) of a
+        //- GeometricField<Type, PatchField, GeoMesh>
+        template<class Type, template<class> class PatchField, class GeoMesh>
+        void storeOldTimes
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field,
+            PtrList<compressedGeometricField<Type, PatchField, GeoMesh>>&
+                compressedField,
+            const label pos
+        );
+
+        //- Decompress field and its old times into a GeometricField
+        template<class Type, template<class> class PatchField, class GeoMesh>
+        void decompressAll
+        (
+            GeometricField<Type, PatchField, GeoMesh>& field,
+            compressedGeometricField<Type, PatchField, GeoMesh>& current,
+            PtrList<compressedGeometricField<Type, PatchField, GeoMesh>>&
+                oldFields
+        );
+
+        //- Calculate and write compression metrics for a
+        //- compressedGeometricField
+        template<class Type, template<class> class PatchField, class GeoMesh>
+        void addStorageMetricsContribution
+        (
+            const compressedGeometricField<Type, PatchField, GeoMesh>&
+                compField,
+            const PtrList<compressedGeometricField<Type, PatchField, GeoMesh>>&
+                compOldField
+        );
+
+        //- Calculate and write compression metrics for a
+        //- compressedGeometricField
+        template<class Type, template<class> class PatchField, class GeoMesh>
+        void calculateAndWrite
+        (
+            const compressedGeometricField<Type, PatchField, GeoMesh>&
+                compField,
+            const PtrList<compressedGeometricField<Type, PatchField, GeoMesh>>&
+                compOldField,
+            const word& name,
+            label& i
+        );
+
+        //- Function to calculate and write the storage metrics of the
+        //- checkpoint
+        virtual void calculateStorageMetrics() override;
+
+
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        fullIncompressibleVars(const fullIncompressibleVars&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const fullIncompressibleVars&) = delete;
+
+
+public:
+
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("fullIncompressibleVars");
+
+
+    // Constructors
+
+        fullIncompressibleVars
+        (
+            incompressibleVars& vs,
+            storageParameters& storageParams,
+            label a = 2
+        );
+
+
+    //- Destructor
+    virtual ~fullIncompressibleVars() = default;
+
+
+    // Member Functions
+
+        //- Function to compress the incompressibleVars
+        void compress() override;
+
+        //- Function to decompress the incompressible vars and
+        //  update the incompressibleVars with the decompressed fields
+        void decompress
+        (
+            incompressibleVars& vars
+        ) override;
+
+        void decompress();
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "fullIncompressibleVarsTemplates.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/compressedIncompressible/fullIncompressibleVars/fullIncompressibleVarsTemplates.C

@@ -0,0 +1,146 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2007-2019 PCOpt/NTUA
+    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2019 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void Foam::fullIncompressibleVars::storeOldTimes
+(
+    GeometricField<Type, PatchField, GeoMesh>& field,
+    PtrList<compressedGeometricField<Type, PatchField, GeoMesh>>&
+        compressedField,
+    const label pos
+)
+{
+    // This object is constructed to store the primal solution of time-step i.
+    // The implication is that this happens exactly before solving for i+1,
+    // meaning that the time has shifted and so have the instanteneous primal
+    // fields. So by the time the function is called, UInst() contains the
+    // solution of ith time-step, as an initialization to the solution that it
+    // will be computed at the (i+1)th time-step, UInst().oldTime() contains
+    // also the solution of the ith time-step and UInst().oldTime().oldTime(),
+    // if set, the solution of the (i-1)th time-step. The solution of the
+    // (i-2)th time-step is not necessary to be stored for the continuation of
+    // the run. So, UInst() and UInst().oldTime().oldTime(), if set, are
+    // stored.
+    label nOldTimes = min(field.nOldTimes(), a_);
+    if (nOldTimes > 1)
+    {
+        GeometricField<Type, PatchField, GeoMesh>* oldField = &field.oldTime();
+        compressedField.setSize(nOldTimes-1);
+        for (label i=0; i<nOldTimes-1; i++)
+        {
+            oldField = &oldField->oldTime();
+            compressedField.set
+            (
+                i,
+                compressedGeometricField<Type, PatchField, GeoMesh>::New
+                (
+                    *oldField,
+                    storageParams_,
+                    pos,
+                    k_
+                )
+            );
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void Foam::fullIncompressibleVars::decompressAll
+(
+    GeometricField<Type, PatchField, GeoMesh>& GeomField,
+    compressedGeometricField<Type, PatchField, GeoMesh>& current,
+    PtrList<compressedGeometricField<Type, PatchField, GeoMesh>>& oldFields
+)
+{
+    // Due to the implication described in storeOldTimes(...) function, the
+    // reference to the GeometricField of the solver that each element of the
+    // oldFields_ is not correct. For example, for a second order time-scheme,
+    // oldFields_ has only one elememt which holds a reference to the
+    // oldTime().oldTime() of the GeometricField known to the solver.
+    // Nevertheless, its stored values must be appended to the oldTime() of the
+    // GeometricField known to the solver.
+    current.decompress();
+    if ( GeomField.nOldTimes() > 1 )
+    {
+        GeometricField<Type, PatchField, GeoMesh>* oldGeomField = &GeomField;
+        //- Scanning only what it has been stored:
+        //   i) At the first time-step, nOldTimes() may be zero, but upon
+        //      reconstruction the noldTimes of the variablesSet of the solver
+        //      will be 1 or 2.
+        //  ii) if (a=1) the oldTimes are not stored and as a result can not
+        //      be retrieved.
+        forAll(oldFields, iPtr)
+        {
+            oldGeomField = &oldGeomField->oldTime();
+            oldFields[iPtr].decompress(*oldGeomField);
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void Foam::fullIncompressibleVars::addStorageMetricsContribution
+(
+    const compressedGeometricField<Type, PatchField, GeoMesh>& compField,
+    const PtrList<compressedGeometricField<Type, PatchField, GeoMesh>>&
+        compOldField
+)
+{
+    forAll (storageMetrics_, Ic)
+    {
+        storageMetrics_[Ic] += compField.storageMetrics()[Ic];
+        forAll(compOldField, iPtr)
+        {
+            storageMetrics_[Ic] += compOldField[iPtr].storageMetrics()[Ic];
+        }
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void Foam::fullIncompressibleVars::calculateAndWrite
+(
+    const compressedGeometricField<Type, PatchField, GeoMesh>& compField,
+    const PtrList<compressedGeometricField<Type, PatchField, GeoMesh>>&
+        compOldField,
+    const word& name,
+    label& i
+)
+{
+    addStorageMetricsContribution(compField, compOldField);
+    write(++i);
+    writeLog(name);
+    storageMetrics_ = Zero;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/compressedIncompressible/shortIncompressibleVars/shortIncompressibleVars.C

@@ -0,0 +1,124 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "shortIncompressibleVars.H"
+#include "addToRunTimeSelectionTable.H"
+#include "IOmanip.H"
+#include "profiling.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+defineTypeNameAndDebug(shortIncompressibleVars, 0);
+addToRunTimeSelectionTable
+(
+    compressedIncompressibleVars,
+    shortIncompressibleVars,
+    dictionary
+);
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+shortIncompressibleVars::shortIncompressibleVars
+(
+    incompressibleVars& vs,
+    storageParameters& storageParams
+)
+:
+    compressedIncompressibleVars(vs, storageParams)
+{}
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void shortIncompressibleVars::compress()
+{
+    addProfiling(shortIncompressibleVars, "shortIncompressibleVars::compress");
+    //scalar startTime = mesh_.time().elapsedCpuTime();
+    p_().compress();
+    DebugInfo
+        << "DEBUG: p field stored" << endl;
+    phi_().compress();
+    DebugInfo
+        << "DEBUG: phi field stored" << endl;
+    U_().compress();
+    DebugInfo
+        << "DEBUG: U field stored" << endl;
+    forAll (RASModelVars_, iPtr)
+    {
+        RASModelVars_[iPtr].compress();
+        DebugInfo
+            << "DEBUG: " << iPtr + 1 << "th turbulence model field stored"
+            << endl;
+    }
+    //scalar endTime = mesh_.time().elapsedCpuTime();
+}
+
+
+void shortIncompressibleVars::decompress
+(
+    incompressibleVars& vars
+)
+{
+    addProfiling
+        (shortIncompressibleVars, "shortIncompressibleVars::decompress");
+    // Phi must be retrieved first, since the BCs of p and U might depend on
+    // flux
+    phi_().decompress(vars.phiInst());
+    DebugInfo
+        << "DEBUG: phi field retrieved" << endl;
+    p_().decompress(vars.pInst());
+    DebugInfo
+        << "DEBUG: p field retrieved" << endl;
+    U_().decompress(vars.UInst());
+    DebugInfo
+        << "DEBUG: U field retrieved" << endl;
+    incompressible::RASModelVariables& rasVars = vars.RASModelVariables()();
+    if (rasVars.hasTMVar1())
+    {
+        RASModelVars_[0].decompress(rasVars.TMVar1Inst());
+        DebugInfo
+            << "DEBUG: 1st turbulence model field retrieved" << endl;
+    }
+    if (rasVars.hasTMVar2())
+    {
+        RASModelVars_[1].decompress(rasVars.TMVar2Inst());
+        DebugInfo
+            << "DEBUG: 2nd turbulence model field retrieved" << endl;
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/compressedIncompressible/shortIncompressibleVars/shortIncompressibleVars.H

@@ -0,0 +1,99 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Class
+    Foam::shortIncompressibleVars
+
+Description
+    Compresses the current time-instance known by the primal solvers.
+    Does not include oldTimes
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef shortIncompressibleVars_H
+#define shortIncompressibleVars_H
+
+#include "compressedIncompressibleVars.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                   Class shortIncompressibleVars Declaration
+\*---------------------------------------------------------------------------*/
+
+class shortIncompressibleVars
+:
+    public compressedIncompressibleVars
+{
+public:
+
+
+    // Static Data Members
+
+        //- Run-time type information
+        TypeName("shortIncompressibleVars");
+
+
+    // Constructors
+
+        shortIncompressibleVars
+        (
+            incompressibleVars& vs,
+            storageParameters& storageParams
+        );
+
+
+    //- Destructor
+    virtual ~shortIncompressibleVars() = default;
+
+
+    // Member Functions
+
+        //- Compress the incompressibleVars
+        void compress() override;
+
+        //- Function to return the compression metrics (initial size,
+        //- compressed size if compression is applied, etc)
+        void decompress
+        (
+            incompressibleVars& vars
+        ) override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/incompressible/incompressibleVars.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2021 PCOpt/NTUA
-    Copyright (C) 2013-2021 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -103,12 +103,11 @@ void incompressibleVars::setInitFields()
     // are allocated automatically in RASModelVariables
     if (solverControl_.storeInitValues())
     {
-        pInitPtr_.reset(new volScalarField(pInst().name() + "Init", pInst()));
-        UInitPtr_.reset(new volVectorField(UInst().name() + "Init", UInst()));
-        phiInitPtr_.reset
-        (
-            new surfaceScalarField(phiInst().name() + "Init", phiInst())
-        );
+        DebugInfo
+            << "Allocating Initial Primal Fields" << endl;
+        setInitField(pInitPtr_, pInst());
+        setInitField(UInitPtr_, UInst());
+        setInitField(phiInitPtr_, phiInst());
     }
 }
 
@@ -121,52 +120,9 @@ void incompressibleVars::setMeanFields()
     if (solverControl_.average())
     {
         Info<< "Allocating Mean Primal Fields" << endl;
-        pMeanPtr_.reset
-        (
-            new volScalarField
-            (
-                IOobject
-                (
-                    pInst().name()+"Mean",
-                    mesh_.time().timeName(),
-                    mesh_,
-                    IOobject::READ_IF_PRESENT,
-                    IOobject::AUTO_WRITE
-                ),
-                pInst()
-            )
-        );
-        UMeanPtr_.reset
-        (
-            new volVectorField
-            (
-                IOobject
-                (
-                    UInst().name()+"Mean",
-                    mesh_.time().timeName(),
-                    mesh_,
-                    IOobject::READ_IF_PRESENT,
-                    IOobject::AUTO_WRITE
-                ),
-                UInst()
-            )
-        );
-        phiMeanPtr_.reset
-        (
-            new surfaceScalarField
-            (
-                IOobject
-                (
-                    phiInst().name()+"Mean",
-                    mesh_.time().timeName(),
-                    mesh_,
-                    IOobject::READ_IF_PRESENT,
-                    IOobject::AUTO_WRITE
-                ),
-                phiInst()
-            )
-        );
-
+        setMeanField(pMeanPtr_, pInst(), mesh_);
+        setMeanField(UMeanPtr_, UInst(), mesh_);
+        setMeanField(phiMeanPtr_, phiInst(), mesh_);
         // Correct boundary conditions if necessary
         if (correctBoundaryConditions_)
         {
@@ -230,7 +186,8 @@ void incompressibleVars::correctTurbulentBoundaryConditions()
 incompressibleVars::incompressibleVars
 (
     fvMesh& mesh,
-    solverControl& SolverControl
+    solverControl& SolverControl,
+    scalar readTime
 )
 :
     variablesSet(mesh, SolverControl.solverDict()),
@@ -242,9 +199,9 @@ incompressibleVars::incompressibleVars
     turbulence_(nullptr),
     RASModelVariables_(nullptr),
 
-    pInitPtr_(nullptr),
-    UInitPtr_(nullptr),
-    phiInitPtr_(nullptr),
+    pInitPtr_(),
+    UInitPtr_(),
+    phiInitPtr_(),
 
     pMeanPtr_(nullptr),
     UMeanPtr_(nullptr),
@@ -254,11 +211,43 @@ incompressibleVars::incompressibleVars
     (
         SolverControl.solverDict().subOrEmptyDict("fieldReconstruction").
             getOrDefault<bool>("reconstruct", false)
+    ),
+    solDirs_((mesh.solutionD() + Vector<label>::one)/2),
+    writeFields_
+    (
+        SolverControl.solverDict().getOrDefault<bool>("writeFields", true)
     )
 {
+    // Necessary for continuation of unsteady solvers. For steady solvers
+    // should have no effect
+    Time& time = const_cast<Time&>(mesh_.time());
+    const dimensionedScalar startTime = mesh_.time();
+    const label startTimeIndex = mesh_.time().timeIndex();
+    if (readTime != -1)
+    {
+        // Set time to readTime. Time-index remains unchanged, since
+        // it does not influence fields reading
+        DebugInfo
+            << "Initializing primal fields begin: time changes to "
+            << ::Foam::name(readTime) << endl;
+        time.setTime(readTime, startTimeIndex);
+    }
     setFields();
     setInitFields();
     setMeanFields();
+    storeAllocatedFieldNames();
+    if (readTime != -1)
+    {
+        DebugInfo
+            << "Initializing primal fields end: time changes to "
+            << ::Foam::name(startTime.value()) << endl;
+        // Restore time
+        time.setTime(startTime, startTimeIndex);
+    }
+    if (!writeFields_)
+    {
+        setWriteOption(IOobject::NO_WRITE);
+    }
 }
 
 
@@ -276,18 +265,32 @@ incompressibleVars::incompressibleVars
     turbulence_(nullptr),
     RASModelVariables_(vs.RASModelVariables_.clone()),
 
-    pInitPtr_(allocateRenamedField(vs.pInitPtr_)),
-    UInitPtr_(allocateRenamedField(vs.UInitPtr_)),
-    phiInitPtr_(allocateRenamedField(vs.phiInitPtr_)),
+    pInitPtr_(vs.pInitPtr_.size()),
+    UInitPtr_(vs.UInitPtr_.size()),
+    phiInitPtr_(vs.phiInitPtr_.size()),
 
     pMeanPtr_(allocateRenamedField(vs.pMeanPtr_)),
-    UMeanPtr_(allocateRenamedField(UMeanPtr_)),
+    UMeanPtr_(allocateRenamedField(vs.UMeanPtr_)),
     phiMeanPtr_(allocateRenamedField(vs.phiMeanPtr_)),
 
-    correctBoundaryConditions_(vs.correctBoundaryConditions_)
+    correctBoundaryConditions_(vs.correctBoundaryConditions_),
+    allocatedFieldNames_(vs.allocatedFieldNames_),
+    solDirs_(vs.solDirs_)
 {
     DebugInfo
         << "Calling incompressibleVars copy constructor" << endl;
+    forAll(pInitPtr_, i)
+    {
+        pInitPtr_.set(i, allocateRenamedField(vs.pInitPtr_[i]));
+    }
+    forAll(UInitPtr_, i)
+    {
+        UInitPtr_.set(i, allocateRenamedField(vs.UInitPtr_[i]));
+    }
+    forAll(phiInitPtr_, i)
+    {
+        phiInitPtr_.set(i, allocateRenamedField(vs.phiInitPtr_[i]));
+    }
 }
 
 
@@ -302,6 +305,23 @@ autoPtr<variablesSet> incompressibleVars::clone() const
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
+void incompressibleVars::storeAllocatedFieldNames()
+{
+    allocatedFieldNames_.setSize(3);
+    allocatedFieldNames_[0] = pInst().name();
+    allocatedFieldNames_[1] = phiInst().name();
+    allocatedFieldNames_[2] = UInst().name();
+    if (RASModelVariables_().hasTMVar1())
+    {
+        allocatedFieldNames_.append(RASModelVariables_().TMVar1Inst().name());
+    }
+    if (RASModelVariables_().hasTMVar2())
+    {
+        allocatedFieldNames_.append(RASModelVariables_().TMVar2Inst().name());
+    }
+}
+
+
 const volScalarField& incompressibleVars::p() const
 {
     if (solverControl_.useAveragedFields())
@@ -366,6 +386,7 @@ const surfaceScalarField& incompressibleVars::phi() const
     }
 }
 
+
 surfaceScalarField& incompressibleVars::phi()
 {
     if (solverControl_.useAveragedFields())
@@ -384,9 +405,9 @@ void incompressibleVars::restoreInitValues()
     if (solverControl_.storeInitValues())
     {
         Info<< "Restoring field values to initial ones" << endl;
-        pInst() == pInitPtr_();
-        UInst() == UInitPtr_();
-        phiInst() == phiInitPtr_();
+        variablesSet::restoreFieldInitialization(pInitPtr_, pInst());
+        variablesSet::restoreFieldInitialization(phiInitPtr_, phiInst());
+        variablesSet::restoreFieldInitialization(UInitPtr_, UInst());
         RASModelVariables_().restoreInitValues();
     }
 }
@@ -428,10 +449,28 @@ void incompressibleVars::computeMeanFields()
 }
 
 
+void incompressibleVars::computeMeanUnsteadyFields()
+{
+    if (solverControl_.doAverageTime())
+    {
+        Info<< "Averaging fields" << endl;
+        const scalar dt = mesh_.time().deltaTValue();
+        const scalar elapsedTime
+            = mesh_.time().value() - solverControl_.averageStartTime();
+        scalar oneOverItP1 = dt/(elapsedTime + dt);
+        scalar mult = elapsedTime/(elapsedTime + dt);
+        pMeanPtr_() == pMeanPtr_()*mult + pInst()*oneOverItP1;
+        UMeanPtr_() == UMeanPtr_()*mult + UInst()*oneOverItP1;
+        phiMeanPtr_() == phiMeanPtr_()*mult + phiInst()*oneOverItP1;
+        RASModelVariables_().computeMeanUnsteadyFields();
+    }
+}
+
+
 void incompressibleVars::correctBoundaryConditions()
 {
     correctNonTurbulentBoundaryConditions();
-    RASModelVariables_().correctBoundaryConditions(turbulence_());
+    correctTurbulentBoundaryConditions();
 }
 
 
@@ -461,6 +500,16 @@ void incompressibleVars::transfer(variablesSet& vars)
 }
 
 
+void incompressibleVars::validateTurbulence()
+{
+    // Update nut
+    if (RASModelVariables_().hasNut())
+    {
+        turbulence()->validate();
+    }
+}
+
+
 bool incompressibleVars::write() const
 {
     // Write dummy fields, for continuation only
@@ -501,6 +550,56 @@ bool incompressibleVars::write() const
 }
 
 
+fvMesh& incompressibleVars::mesh() const
+{
+    return mesh_;
+}
+
+
+const solverControl& incompressibleVars::solverControlReference() const
+{
+    return solverControl_;
+}
+
+
+const wordList& incompressibleVars::allocatedFieldNames() const
+{
+    return allocatedFieldNames_;
+}
+
+
+const Vector<label>& incompressibleVars::solDirs() const
+{
+    return solDirs_;
+}
+
+
+void incompressibleVars::adjustAverageStartTime(const scalar& offset)
+{
+    solverControl_.averageStartTime() += offset;
+}
+
+
+void incompressibleVars::setWriteOption(IOobject::writeOption w)
+{
+    if (!writeFields_)
+    {
+        w = IOobject::NO_WRITE;
+    }
+    pInst().writeOpt() = w;
+    phiInst().writeOpt() = w;
+    UInst().writeOpt() = w;
+    if (solverControl_.doAverageTime())
+    {
+        pMeanPtr_->writeOpt() = w;
+        phiMeanPtr_->writeOpt() = w;
+        UMeanPtr_->writeOpt() = w;
+    }
+    incompressible::RASModelVariables& rasVars = RASModelVariables_();
+    rasVars.setWriteOption(w);
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/incompressible/incompressibleVars.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2021 PCOpt/NTUA
-    Copyright (C) 2013-2021 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -72,10 +72,12 @@ protected:
         autoPtr<incompressible::RASModelVariables> RASModelVariables_;
         //autoPtr<volScalarField> TPtr_;
 
-        //- Keep a copy of the initial field values if necessary
-        autoPtr<volScalarField> pInitPtr_;
-        autoPtr<volVectorField> UInitPtr_;
-        autoPtr<surfaceScalarField> phiInitPtr_;
+        //- Keep a copy of the initial values if necessary.
+        //  If oldTimes are present, keep them in separate GeometricFields to
+        //  avoid been overwritten upon calling GeometricField::storeOldTimes
+        PtrList<volScalarField> pInitPtr_;
+        PtrList<volVectorField> UInitPtr_;
+        PtrList<surfaceScalarField> phiInitPtr_;
 
         //- Manage mean fields. Turbulent mean fields are managed
         //- in RASModelVariables
@@ -88,6 +90,17 @@ protected:
         //  (e.g. averaging, redistribution)
         bool correctBoundaryConditions_;
 
+        //- Names of the primal fields that are allocated.
+        //  The size of the list is properly adjusted
+        wordList allocatedFieldNames_;
+
+        //- Return the vector of solved-for directions in mesh.
+        //  1 indicates valid direction and 0 an invalid direction.
+        const Vector<label> solDirs_;
+
+        //- Should the solver fields be written
+        bool writeFields_;
+
 
     // Protected Member Functions
 
@@ -112,6 +125,10 @@ protected:
         //- No copy assignment
         void operator=(const incompressibleVars&);
 
+        //- Function to fill the wordList containing the names of the primal
+        //- fields that are allocated.
+        void storeAllocatedFieldNames();
+
 
 public:
 
@@ -127,7 +144,8 @@ public:
         incompressibleVars
         (
             fvMesh& mesh,
-            solverControl& SolverControl
+            solverControl& SolverControl,
+            scalar readTime = -1
         );
 
         //- Copy constructor
@@ -230,6 +248,9 @@ public:
             //- Compute mean fields on the fly
             void computeMeanFields();
 
+            //- Compute mean fields on the fly: unsteady runs
+            void computeMeanUnsteadyFields();
+
             //- correct boundaryconditions for all volFields
             void correctBoundaryConditions();
 
@@ -250,9 +271,33 @@ public:
             //- Transfer the fields of another variablesSet to this
             virtual void transfer(variablesSet& vars);
 
+            //- Update nut
+            virtual void validateTurbulence();
+
             //- Write dummy turbulent fields to allow for continuation in
             //- multi-point, turbulent runs
             bool write() const;
+
+            //- Return const reference to the fvMesh
+            fvMesh& mesh() const;
+
+            //- Return const reference to the solverDict
+            const solverControl& solverControlReference() const;
+
+            //- const reference to the wordList containing the names of
+            //- the primal fields that are allocated.
+            const wordList& allocatedFieldNames() const override;
+
+            //- const reference to the solution directions
+            //- of the solver.
+            const Vector<label>& solDirs() const;
+
+            //- Set averaging start time in solverControl.
+            //  Required by unsteady runs
+            void adjustAverageStartTime(const scalar& offset) override;
+
+            //- Set writeOption of all primal fields
+            void setWriteOption(IOobject::writeOption w);
 };
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/incompressibleAdjoint/incompressibleAdjointVars.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2021 PCOpt/NTUA
-    Copyright (C) 2013-2021 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -61,12 +61,34 @@ incompressibleAdjointVars::incompressibleAdjointVars
             *this,
             objManager
         )
+    ),
+    writeFields_
+    (
+        SolverControl.solverDict().getOrDefault<bool>("writeFields", true)
     )
-{}
+{
+    if (!writeFields_)
+    {
+        setWriteOption(IOobject::NO_WRITE);
+    }
+}
 
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
+void incompressibleAdjointVars::restoreInitValues()
+{
+    if (solverControl_.storeInitValues())
+    {
+        Info<< "Restoring field values to initial ones" << endl;
+        variablesSet::resetAdjointField(paInst());
+        variablesSet::resetAdjointField(UaInst());
+        variablesSet::resetAdjointField(phiaInst());
+        adjointTurbulence_().restoreInitValues();
+    }
+}
+
+
 void incompressibleAdjointVars::resetMeanFields()
 {
     if (solverControl_.average())
@@ -103,6 +125,26 @@ void incompressibleAdjointVars::computeMeanFields()
 }
 
 
+void incompressibleAdjointVars::computeMeanUnsteadyFields
+(
+    const scalar endTime
+)
+{
+    if (solverControl_.doAverageTime())
+    {
+        Info<< "Averaging fields" << endl;
+        const scalar dt = mesh_.time().deltaTValue();
+        const scalar elapsedTime = endTime - mesh_.time().value();
+        scalar oneOverItP1 = dt/(elapsedTime + dt);
+        scalar mult = elapsedTime/(elapsedTime + dt);
+        paMeanPtr_() == paMeanPtr_()*mult + paInst()*oneOverItP1;
+        UaMeanPtr_() == UaMeanPtr_()*mult + UaInst()*oneOverItP1;
+        phiaMeanPtr_() == phiaMeanPtr_()*mult + phiaInst()*oneOverItP1;
+        adjointTurbulence_().computeMeanUnsteadyFields(endTime);
+    }
+}
+
+
 void incompressibleAdjointVars::nullify()
 {
     incompressibleAdjointMeanFlowVars::nullify();
@@ -137,6 +179,28 @@ void incompressibleAdjointVars::updatePrimalBasedQuantities()
 }
 
 
+void incompressibleAdjointVars::write()
+{
+    if (writeFields_)
+    {
+        incompressibleAdjointMeanFlowVars::write();
+        adjointTurbulence_->writeFields();
+    }
+}
+
+
+void incompressibleAdjointVars::setWriteOption(IOobject::writeOption w)
+{
+    if (!writeFields_)
+    {
+        w = IOobject::NO_WRITE;
+    }
+
+    incompressibleAdjointMeanFlowVars::setWriteOption(w);
+    adjointTurbulence_->setWriteOption(w);
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/incompressibleAdjoint/incompressibleAdjointVars.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2021 PCOpt/NTUA
-    Copyright (C) 2013-2021 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -64,6 +64,9 @@ protected:
         //- Adjoint to the turbulence model
         autoPtr<incompressibleAdjoint::adjointRASModel> adjointTurbulence_;
 
+        //- Should the solver fields be written
+        bool writeFields_;
+
 
     // Protected Member Functions
 
@@ -111,18 +114,30 @@ public:
             inline autoPtr<incompressibleAdjoint::adjointRASModel>&
                 adjointTurbulence();
 
+            //- Restore field values to the initial ones
+            void restoreInitValues();
+
             //- Reset mean fields to zero
             void resetMeanFields();
 
-            //- Compute mean fields on the fly
+            //- Compute mean fields on the fly: steady runs
             void computeMeanFields();
 
+            //- Compute mean fields on the fly: unsteady runs
+            void computeMeanUnsteadyFields(const scalar endTime);
+
             //- Nullify all adjoint fields
             virtual void nullify();
 
             //- Update primal based quantities of the adjoint boundary
             //  conditions
             virtual void updatePrimalBasedQuantities();
+
+            //- Write all adjoint fields
+            virtual void write();
+
+            //- Set writeOption of all adjoint fields
+            void setWriteOption(IOobject::writeOption w);
 };
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/incompressibleAdjointMeanFlow/incompressibleAdjointMeanFlowVars.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2021 PCOpt/NTUA
-    Copyright (C) 2013-2021 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -57,6 +57,7 @@ void incompressibleAdjointMeanFlowVars::setFields()
     mesh_.setFluxRequired(paPtr_->name());
 }
 
+
 void incompressibleAdjointMeanFlowVars::setMeanFields()
 {
     // Allocate mean fields
@@ -65,51 +66,9 @@ void incompressibleAdjointMeanFlowVars::setMeanFields()
     if (solverControl_.average())
     {
         Info<< "Allocating Mean Adjoint Fields" << endl;
-        paMeanPtr_.reset
-        (
-            new volScalarField
-            (
-                IOobject
-                (
-                    paInst().name() + "Mean",
-                    mesh_.time().timeName(),
-                    mesh_,
-                    IOobject::READ_IF_PRESENT,
-                    IOobject::AUTO_WRITE
-                ),
-                paInst()
-            )
-        );
-        UaMeanPtr_.reset
-        (
-            new volVectorField
-            (
-                IOobject
-                (
-                    UaInst().name() + "Mean",
-                    mesh_.time().timeName(),
-                    mesh_,
-                    IOobject::READ_IF_PRESENT,
-                    IOobject::AUTO_WRITE
-                ),
-                UaInst()
-            )
-        );
-        phiaMeanPtr_.reset
-        (
-            new surfaceScalarField
-            (
-                IOobject
-                (
-                    phiaInst().name() + "Mean",
-                    mesh_.time().timeName(),
-                    mesh_,
-                    IOobject::READ_IF_PRESENT,
-                    IOobject::AUTO_WRITE
-                ),
-                phiaInst()
-            )
-        );
+        variablesSet::setMeanField(paMeanPtr_, paInst(), mesh_);
+        variablesSet::setMeanField(UaMeanPtr_, UaInst(), mesh_);
+        variablesSet::setMeanField(phiaMeanPtr_, phiaInst(), mesh_);
     }
 }
 
@@ -236,12 +195,43 @@ const solverControl& incompressibleAdjointMeanFlowVars::getSolverControl() const
 
 void incompressibleAdjointMeanFlowVars::nullify()
 {
+    // Nullify instantaneous fields
     variablesSet::nullifyField(paPtr_());
     variablesSet::nullifyField(UaPtr_());
     variablesSet::nullifyField(phiaPtr_());
 }
 
 
+void incompressibleAdjointMeanFlowVars::write()
+{
+    //  Write instantaneous fields
+    variablesSet::writeField(paPtr_());
+    variablesSet::writeField(UaPtr_());
+    variablesSet::writeField(phiaPtr_());
+    //  Write mean fields
+    if (solverControl_.average())
+    {
+        variablesSet::writeField(paMeanPtr_());
+        variablesSet::writeField(UaMeanPtr_());
+        variablesSet::writeField(phiaMeanPtr_());
+    }
+}
+
+
+void incompressibleAdjointMeanFlowVars::setWriteOption(IOobject::writeOption w)
+{
+    paPtr_().writeOpt() = w;
+    UaPtr_().writeOpt() = w;
+    phiaPtr_().writeOpt() = w;
+    if (solverControl_.doAverageTime())
+    {
+        paMeanPtr_->writeOpt() = w;
+        UaMeanPtr_->writeOpt() = w;
+        phiaMeanPtr_->writeOpt() = w;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/incompressibleAdjointMeanFlow/incompressibleAdjointMeanFlowVars.H

@@ -183,6 +183,12 @@ public:
 
             //- Nullify all adjoint fields
             virtual void nullify();
+
+            //- Write all adjoint fields
+            virtual void write();
+
+            //- Set writeOption of all adjoint fields
+            void setWriteOption(IOobject::writeOption w);
 };
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/variablesSet/variablesSet.C

@@ -199,6 +199,32 @@ void variablesSet::transfer(variablesSet& vars)
 }
 
 
+void variablesSet::validateTurbulence()
+{
+    // Does nothing in base
+}
+
+
+const scalarList& variablesSet::storageMetrics() const
+{
+    NotImplemented
+    return demoScalarList_;
+}
+
+
+const wordList& variablesSet::allocatedFieldNames() const
+{
+    NotImplemented
+    return demoWordList_;
+}
+
+
+void variablesSet::adjustAverageStartTime(const scalar& offset)
+{
+    // Does nothing in base
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/variablesSet/variablesSet.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -84,6 +84,10 @@ private:
             const bool useSolverNameForFields
         );
 
+        //- Demo scalarList for virtual function storageMetrics()
+        scalarList demoScalarList_;
+        wordList demoWordList_;
+
 
 protected:
 
@@ -101,12 +105,6 @@ protected:
 
     // Protected Member Functions
 
-        template<class Type, template<class> class PatchField, class GeoMesh>
-        autoPtr<GeometricField<Type, PatchField, GeoMesh>> allocateRenamedField
-        (
-            const autoPtr<GeometricField<Type, PatchField, GeoMesh>>& bf
-        );
-
         //- Swap autoPtrs and rename managed fields
         template<class Type, template<class> class PatchField, class GeoMesh>
         void swapAndRename
@@ -155,6 +153,27 @@ public:
 
         // Set functions. Static in order to be used by other classes as well
 
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static autoPtr<GeometricField<Type, PatchField, GeoMesh>>
+            allocateRenamedField
+            (
+                const refPtr<GeometricField<Type, PatchField, GeoMesh>>& bf
+            );
+
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static autoPtr<GeometricField<Type, PatchField, GeoMesh>>
+            allocateRenamedField
+            (
+                const autoPtr<GeometricField<Type, PatchField, GeoMesh>>& bf
+            );
+
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static autoPtr<GeometricField<Type, PatchField, GeoMesh>>
+            allocateRenamedField
+            (
+                const GeometricField<Type, PatchField, GeoMesh>& bf
+            );
+
             //- Read vol fields
             template<class Type>
             static void setField
@@ -221,8 +240,70 @@ public:
                 GeometricField<Type, PatchField, GeoMesh>& fieldPtr
             );
 
+            //- Write field and old times, if present
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static void writeField
+            (
+                GeometricField<Type, PatchField, GeoMesh>& fieldPtr
+            );
+
+            //- Set initial field
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static void setInitField
+            (
+                PtrList<GeometricField<Type, PatchField, GeoMesh>>& fieldInit,
+                GeometricField<Type, PatchField, GeoMesh>& field
+            );
+
+            //- Reset field to its initial state
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static void restoreFieldInitialization
+            (
+                PtrList<GeometricField<Type, PatchField, GeoMesh>>& exact,
+                GeometricField<Type, PatchField, GeoMesh>& field
+            );
+
+            //- Reset field and old values to zero
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static void resetAdjointField
+            (
+                GeometricField<Type, PatchField, GeoMesh>& field
+            );
+
+            //- Set mean field
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static void setMeanField
+            (
+                refPtr<GeometricField<Type, PatchField, GeoMesh>>& meanFieldPtr,
+                const GeometricField<Type, PatchField, GeoMesh>& field,
+                const fvMesh& mesh
+            );
+
+            //- Set mean field
+            template<class Type, template<class> class PatchField, class GeoMesh>
+            static void setMeanField
+            (
+                autoPtr<GeometricField<Type, PatchField, GeoMesh>>& meanFieldPtr,
+                const GeometricField<Type, PatchField, GeoMesh>& field,
+                const fvMesh& mesh
+            );
+
             //- Transfer the fields of another variablesSet to this
             virtual void transfer(variablesSet& vars);
+
+            //- Update nut
+            virtual void validateTurbulence();
+
+            //- Function to return the compression metrics (initial size,
+            //- compressed size, etc)
+            virtual const scalarList& storageMetrics() const;
+
+            //- Function to return the names of all the primal fields that are
+            //- allocated
+            virtual const wordList& allocatedFieldNames() const;
+
+            //- Does nothing in base
+            virtual void adjustAverageStartTime(const scalar& offset);
 };
 
 

src/optimisation/adjointOptimisation/adjoint/solvers/variablesSet/variablesSet/variablesSetTemplates.C

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2007-2019 PCOpt/NTUA
-    Copyright (C) 2013-2019 FOSS GP
+    Copyright (C) 2007-2022 PCOpt/NTUA
+    Copyright (C) 2013-2022 FOSS GP
     Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
@@ -76,7 +76,7 @@ GeometricField<Type, PatchField, GeoMesh>* variablesSet::allocateNamedField
     DebugInfo
         << bField << endl;
 
-    return (new fieldType(io, mesh, dict));
+    return (new fieldType(io, mesh, dict, true));
 }
 
 
@@ -161,31 +161,6 @@ bool variablesSet::readFieldOK
 
 // * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
 
-template<class Type, template<class> class PatchField, class GeoMesh>
-autoPtr<GeometricField<Type, PatchField, GeoMesh>>
-variablesSet::allocateRenamedField
-(
-    const autoPtr<GeometricField<Type, PatchField, GeoMesh>>& bf
-)
-{
-    typedef GeometricField<Type, PatchField, GeoMesh> fieldType;
-    autoPtr<fieldType> returnField(nullptr);
-    if (bf.valid())
-    {
-        const word timeName = bf().mesh().time().timeName();
-        returnField.reset
-        (
-            new fieldType
-            (
-                bf().name() + timeName,
-                bf()
-            )
-        );
-    }
-    return returnField;
-}
-
-
 template<class Type, template<class> class PatchField, class GeoMesh>
 void variablesSet::swapAndRename
 (
@@ -217,6 +192,53 @@ void variablesSet::swapAndRename
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
+template<class Type, template<class> class PatchField, class GeoMesh>
+autoPtr<GeometricField<Type, PatchField, GeoMesh>>
+variablesSet::allocateRenamedField
+(
+    const refPtr<GeometricField<Type, PatchField, GeoMesh>>& bf
+)
+{
+    typedef GeometricField<Type, PatchField, GeoMesh> fieldType;
+    autoPtr<fieldType> returnField(nullptr);
+    if (bf.valid())
+    {
+        returnField = allocateRenamedField(bf());
+    }
+    return returnField;
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+autoPtr<GeometricField<Type, PatchField, GeoMesh>>
+variablesSet::allocateRenamedField
+(
+    const autoPtr<GeometricField<Type, PatchField, GeoMesh>>& bf
+)
+{
+    typedef GeometricField<Type, PatchField, GeoMesh> fieldType;
+    autoPtr<fieldType> returnField(nullptr);
+    if (bf.valid())
+    {
+        returnField = allocateRenamedField(bf());
+    }
+    return returnField;
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+autoPtr<GeometricField<Type, PatchField, GeoMesh>>
+variablesSet::allocateRenamedField
+(
+    const GeometricField<Type, PatchField, GeoMesh>& bf
+)
+{
+    typedef GeometricField<Type, PatchField, GeoMesh> fieldType;
+    const word timeName = bf.mesh().time().timeName();
+    return autoPtr<fieldType>::New(bf.name() + timeName, bf);
+}
+
+
 template<class Type>
 void variablesSet::setField
 (
@@ -358,6 +380,155 @@ void variablesSet::nullifyField
 }
 
 
+template<class Type, template<class> class PatchField, class GeoMesh>
+void variablesSet::writeField
+(
+    GeometricField<Type, PatchField, GeoMesh>& field
+)
+{
+    field.write();
+    for (label i = 0; i<field.nOldTimes() - 1; ++i)
+    {
+        writeField(field.oldTime());
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void variablesSet::setInitField
+(
+    PtrList<GeometricField<Type, PatchField, GeoMesh>>& fieldInit,
+    GeometricField<Type, PatchField, GeoMesh>& field
+)
+{
+    // Store fields at the current and (nOldTimes - 1) time-steps
+    // since the last oldTime value is not for restarts
+    // Avoiding the storage to a new GeometricField with its oldTimes set
+    // due to the overwriting of the latter when time advances
+    typedef GeometricField<Type, PatchField, GeoMesh> fieldType;
+    fieldInit.setSize(max(field.nOldTimes(), 1));
+    fieldInit.set(0, new fieldType(field.name() + "Init" + name(0), field));
+    GeometricField<Type, PatchField, GeoMesh>* oldField = &field;
+    for (label i = 1; i < fieldInit.size(); ++i)
+    {
+        oldField = &oldField->oldTime();
+        fieldInit.set
+        (
+            i,
+            new fieldType(field.name() + "Init" + name(i), *oldField)
+        );
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void variablesSet::restoreFieldInitialization
+(
+    PtrList<GeometricField<Type, PatchField, GeoMesh>>& exact,
+    GeometricField<Type, PatchField, GeoMesh>& field
+)
+{
+    if (!exact.size())
+    {
+        FatalErrorInFunction
+            << "DataList to be used for restoring primal "
+            << "fields is not set" << endl
+            << exit(FatalError);
+    }
+    // Restore GeometricField together with its oldTimes
+    field == exact[0];
+    label nI(1);
+    GeometricField<Type, PatchField, GeoMesh>* oldField = &field;
+    // Restore old times stored in exact
+    while (nI < exact.size())
+    {
+        oldField = &oldField->oldTime();
+        *oldField == exact[nI];
+        ++nI;
+    }
+    // Covers the rare case of not having read the _0 fields (to be stored in
+    // exact) but there is the need of re-setting the oldTimes
+    while (nI < field.nOldTimes())
+    {
+        oldField = &oldField->oldTime();
+        *oldField == exact[0];
+        nI++;
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void variablesSet::resetAdjointField
+(
+    GeometricField<Type, PatchField, GeoMesh>& field
+)
+{
+    dimensioned<Type> zero(field.dimensions(), Zero);
+    field == zero;
+    // Restore oldTimes to zero too
+    GeometricField<Type, PatchField, GeoMesh>* oldField = &field;
+    for (label i = 0; i < field.nOldTimes(); ++i)
+    {
+        oldField = &oldField->oldTime();
+        *oldField == zero;
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void variablesSet::setMeanField
+(
+    refPtr<GeometricField<Type, PatchField, GeoMesh>>& meanFieldPtr,
+    const GeometricField<Type, PatchField, GeoMesh>& field,
+    const fvMesh& mesh
+)
+{
+    meanFieldPtr.reset
+    (
+        new GeometricField<Type, PatchField, GeoMesh>
+        (
+            IOobject
+            (
+                field.name() + "Mean",
+                mesh.time().timeName(),
+                mesh,
+                IOobject::READ_IF_PRESENT,
+                IOobject::AUTO_WRITE
+            ),
+            field,
+            false
+        )
+    );
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+void variablesSet::setMeanField
+(
+    autoPtr<GeometricField<Type, PatchField, GeoMesh>>& meanFieldPtr,
+    const GeometricField<Type, PatchField, GeoMesh>& field,
+    const fvMesh& mesh
+)
+{
+    meanFieldPtr.reset
+    (
+        new GeometricField<Type, PatchField, GeoMesh>
+        (
+            IOobject
+            (
+                field.name()+"Mean",
+                mesh.time().timeName(),
+                mesh,
+                IOobject::READ_IF_PRESENT,
+                IOobject::AUTO_WRITE
+            ),
+            field,
+            false
+        )
+    );
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/binomialCheckPointing/binomialCheckPointing.C

@@ -0,0 +1,748 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "Ostream.H"
+#include "binomialCheckPointing.H"
+#include "memInfo.H"
+#include "addToRunTimeSelectionTable.H"
+#include "IOmanip.H"
+#include "messageStream.H"
+#include "primalSolver.H"
+
+// * * * * * * * * * * * * * Static Member Data  * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(binomialCheckPointing, 0);
+    defineRunTimeSelectionTable(binomialCheckPointing, dictionary);
+    addToRunTimeSelectionTable
+    (
+        primalStorage,
+        binomialCheckPointing,
+        primalStorage
+    );
+}
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+Foam::labelList Foam::binomialCheckPointing::hostStartProcess
+(
+    wordList& hostNames
+) const
+{
+    // Gather host names for all processors
+    wordList machineName(Pstream::nProcs());
+    machineName[Pstream::myProcNo()] = hostName();
+    Pstream::gatherList(machineName);
+    Pstream::scatterList(machineName);
+    hostNames = machineName;
+
+    // Start processor ID for each host; to be resized
+    const label nProcs(Pstream::nProcs());
+    labelList hostStartProcess(nProcs + 1, 0);
+
+    label iHost(0);
+    word prev(word::null);
+    for (label procI = 0; procI < nProcs; ++procI)
+    {
+        if (machineName[procI] != prev)
+        {
+            hostStartProcess[iHost] = procI;
+            prev = machineName[procI];
+            iHost++;
+        }
+    }
+    // Allocate an additional entry for easy looping over start
+    // of this host and the next one
+    hostStartProcess.setSize(iHost + 1);
+    hostStartProcess[iHost] = nProcs;
+    return hostStartProcess;
+}
+
+
+Foam::scalar Foam::binomialCheckPointing::checkPointSize()
+{
+    Time& time = const_cast<Time&>(mesh_.time());
+    label startTimeIndex = mesh_.time().timeIndex();
+    dimensionedScalar startTime = mesh_.time();
+
+    Info<< "CheckPoint size computation:: Time = "
+        << time.timeName() << nl << endl;
+    primalSolver_.solveIter();
+    checkPoint temp(storageParams_());
+    incompressibleVars& incoVars = refCast<incompressibleVars>(variablesSet_);
+    temp.setPlaceHolder(false);
+    temp.store(incoVars);
+
+    time.setTime(startTime, startTimeIndex);
+
+    return temp.storageMetrics()[1];
+}
+
+
+unsigned long long Foam::binomialCheckPointing::maxNumberOfCheckPoints()
+{
+    // Find checkpoint size per processor (in MB)
+    scalarList size(Pstream::nProcs());
+    size[Pstream::myProcNo()] = checkPointSize()*1.e-6;
+    Pstream::gatherList(size);
+    Pstream::scatterList(size);
+    if (!memInfo().valid())
+    {
+        FatalErrorInFunction
+            << "memInfo is invalid" << endl
+            << exit(FatalError);
+    }
+    // Available memory in MB. Is stored on a per-processor base but actually
+    // refers to the host. Use with caution
+    scalarList free(Pstream::nProcs());
+    free[Pstream::myProcNo()] = memInfo().update().free()*1.e-3;
+    Pstream::gatherList(free);
+    Pstream::scatterList(free);
+
+    // Host name, per process
+    wordList hostNames(0);
+    // Start processor ID per host
+    labelList hostStartProcessID(hostStartProcess(hostNames));
+    label nHosts(hostStartProcessID.size() - 1);
+
+    // Determine the number of checkpoints that can be allocated as the
+    // minimum from all hosts
+    labelList hostCheckPointSize(nHosts, 0);
+    label nCheckPoints(pTraits<label>::max);
+    label limitingHostID(-1);
+    for (label iHost = 0; iHost < nHosts; ++iHost)
+    {
+        const label start(hostStartProcessID[iHost]);
+        const label end(hostStartProcessID[iHost + 1]);
+        label& hostSize = hostCheckPointSize[iHost];
+        for (label procI = start; procI < end; ++procI)
+        {
+            hostSize += size[procI];
+        }
+        if (hostSize == 0)
+        {
+            FatalErrorInFunction
+                << "hostSize = 0!!" << endl
+                << exit(FatalError);
+        }
+        scalar val = free[start]/hostSize;
+        label nHostCheckPoints(pTraits<label>::max);
+        if (val <= 0)
+        {
+            FatalErrorInFunction
+                << "free[start], hostSize = " << free[start]
+                << " " << hostSize << endl
+                << exit(FatalError);
+        }
+        else if (val < pTraits<label>::max)
+        {
+            nHostCheckPoints = val;
+        }
+        if (nHostCheckPoints < nCheckPoints)
+        {
+            nCheckPoints = nHostCheckPoints;
+            limitingHostID = iHost;
+        }
+    }
+
+    // Print global check point size
+    Info<< nl << "Global size of a checkpoint is "
+        << sum(size) << " MBs" << nl
+        << "Total free memory in all hosts: "
+        << sum(free)*1.e-3 << " GBs" << endl;
+
+    // Print max number of check points that fit in the most limiting host
+    Info<< "Approximately " << nCheckPoints
+        << " checkpoints can be stored, "
+        << "without accounting for cashed memory " << endl;
+
+    // Print information on a per host basis
+    if (debug > 1)
+    {
+        Info<< nl
+            << setw(23) << "Host" << " | "
+            << setw(23) << "Checkpoint size (kBs)" << " | "
+            << setw(23) << "Available memory (kBs)" << " | "
+            << setw(23) << "Max checkpoints (local)"
+            << nl;
+        for (label iHost = 0; iHost < nHosts; ++iHost)
+        {
+            const label start(hostStartProcessID[iHost]);
+            Info<< setw(23) << hostNames[start] << "   "
+                << setw(23) << hostCheckPointSize[iHost] << "   "
+                << setw(23) << free[start] << "   "
+                << setw(23) << free[start]/hostCheckPointSize[iHost]
+                << endl;
+        }
+        Info<< endl;
+    }
+
+    string limitingHost;
+    if (Pstream::myProcNo() == hostStartProcessID[limitingHostID])
+    {
+        limitingHost = hostName();
+    }
+    reduce(limitingHost, sumOp<word>());
+    Info<< "Limiting factor is host " << limitingHost << nl << endl;
+
+    return nCheckPoints;
+}
+
+
+void Foam::binomialCheckPointing::initialize()
+{
+    nCheckPoints_ = storageDict_.subDict("storageParameters").
+        get<label>("nCheckPoints") + 1;
+    if (nCheckPoints_ < 1)
+    {
+        FatalErrorInFunction
+            << "nCheckPoints = " << nCheckPoints_ << ". Please provide a "
+            << "value >=1" << endl
+            << exit(FatalError);
+    }
+    /*if (storageDict_.subDict("storageParameters").found("nCheckPoints"))
+    {
+        nCheckPoints_ = storageDict_.subDict("storageParameters").
+            get<label>("nCheckPoints");
+    }
+    else
+    {
+        nCheckPoints_ = maxNumberOfCheckPoints();
+    }*/
+    checkPoints_.setSize(nCheckPoints_);
+    indirectAddressing_ = identity(nCheckPoints_);
+    Info<< nl << "Total number of checkpoints = "
+        << nCheckPoints_ << nl << endl;
+    for (label fI = 0; fI < nCheckPoints_; ++fI)
+    {
+        checkPoints_.set(fI, new checkPoint(storageParams_()));
+    }
+}
+
+
+void Foam::binomialCheckPointing::gatherMetrics()
+{
+    if (storageParams_().timing())
+    {
+        for (scalar& smI : storageMetrics_)
+        {
+            reduce(smI, sumOp<scalar>());
+        }
+    }
+}
+
+
+void Foam::binomialCheckPointing::setMetricsFilesPtr()
+{
+    fileName filePath =
+        storageFolder_/"AllOptCycles" + primalSolver_.solverName();
+    if (!isFile(filePath))
+    {
+        DebugInfo
+            << "Creating file: " << filePath << endl;
+        metricsFilePtr_.reset(new OFstream(filePath));
+        if (!metricsFilePtr_()())
+        {
+            FatalErrorInFunction
+                << "Stream has failed." << endl
+                << exit(FatalError);
+        }
+        if (!isFile(filePath))
+        {
+            FatalErrorInFunction
+                << "Error while creating file: " << filePath << endl
+                << exit(FatalError);
+        }
+        unsigned int width = IOstream::defaultPrecision() + 6;
+        metricsFilePtr_()
+            << setw(width) << "nCheckPoints" << tab
+            << setw(width) << "Overall CR (CR_0)" << tab
+            << setw(width) << "ZFP CR (CR_ZFP)" << tab
+            << setw(width) << "Initial Size (Mb)" << tab
+            << setw(width) << "Initial Size Saved (Mb)" << tab
+            << setw(width) << "Compressed Size (Mb)"<< endl;
+    }
+    else
+    {
+        metricsFilePtr_.reset
+        (
+            new OFstream
+                (
+                    filePath,
+                    IOstream::ASCII,
+                    IOstream::currentVersion,
+                    IOstream::UNCOMPRESSED,
+                    true
+                )
+        );
+    }
+}
+
+
+void Foam::binomialCheckPointing::setCheckPointsFilesPtr()
+{
+    fileName filePath =
+        storageFolder_/"checkPoints" + primalSolver_.solverName();
+    if (!isFile(filePath))
+    {
+        DebugInfo
+            << "Creating file: " << filePath << endl;
+        checkPointsFilePtr_.reset(new OFstream(filePath));
+        if (!checkPointsFilePtr_()())
+        {
+            FatalErrorInFunction
+                << "Stream has failed." << endl
+                << exit(FatalError);
+        }
+        if (!isFile(filePath))
+        {
+            FatalErrorInFunction
+                << "Error while creating file: " << filePath << endl
+                << exit(FatalError);
+        }
+        unsigned int width = IOstream::defaultPrecision() + 6;
+        checkPointsFilePtr_()
+            << setw(width) << "S/N" << tab
+            << setw(width) << "TimeIndex" << tab
+            << setw(width) << "Level" << tab
+            << setw(width) << "Time" << tab
+            << setw(width) << "Placeholder" << endl;
+    }
+    else
+    {
+        checkPointsFilePtr_.reset
+        (
+            new OFstream
+                (
+                    filePath,
+                    IOstream::ASCII,
+                    IOstream::currentVersion,
+                    IOstream::UNCOMPRESSED,
+                    true
+                )
+        );
+    }
+}
+
+
+inline void Foam::binomialCheckPointing::writeToFile()
+{
+    if (Pstream::master())
+    {
+        if (!metricsFilePtr_)
+        {
+            setMetricsFilesPtr();
+        }
+        const scalar& initialSize = storageMetrics_[0];
+        const scalar& uncompressedRoughSize = storageMetrics_[1];
+        const scalar& uncompressedSize = storageMetrics_[2];
+        const scalar& compressedSize = storageMetrics_[3];
+
+        unsigned int width = IOstream::defaultPrecision() + 6;
+        metricsFilePtr_()
+            << setprecision(IOstream::defaultPrecision());
+        metricsFilePtr_()
+            << setw(width) << activeCheckPoints_ << tab
+            << setw(width) << uncompressedRoughSize/compressedSize << tab
+            << setw(width) << uncompressedSize/compressedSize << tab
+            << setw(width) << initialSize*1.e-6 << tab
+            << setw(width) << uncompressedRoughSize*1.e-6 << tab
+            << setw(width) << compressedSize*1e-6 << endl;
+        if (!checkPointsFilePtr_)
+        {
+            setCheckPointsFilesPtr();
+        }
+        checkPointsFilePtr_()
+            << setprecision(IOstream::defaultPrecision());
+        for (label fI = 0; fI < nCheckPoints_; ++fI)
+        {
+            const label pos = indirectAddressing_[fI];
+            if (checkPoints_[pos].active())
+            {
+                checkPointsFilePtr_()
+                    << setw(width) << fI << tab
+                    << setw(width) << checkPoints_[pos].timeIndex() << tab
+                    << setw(width) << checkPoints_[pos].level() << tab
+                    << setw(width) << name(checkPoints_[pos].timeValue())
+                    << setw(width) << checkPoints_[pos].placeHolder()
+                    << endl;
+            }
+        }
+        checkPointsFilePtr_() << endl;
+    }
+}
+
+
+void Foam::binomialCheckPointing::calcStorageMetrics()
+{
+    storageMetrics_ = checkPoints_[0].storageMetrics();
+    for (label fI = 1; fI < nCheckPoints_; ++fI)
+    {
+        if (checkPoints_[fI].active() && !checkPoints_[fI].placeHolder())
+        {
+            storageMetrics_ =
+                storageMetrics_
+              + checkPoints_[fI].storageMetrics();
+        }
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::binomialCheckPointing::binomialCheckPointing
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+:
+    primalStorage(primalSolverObj, storageDict),
+    totalSteps_(0),
+    recomputationSteps_(0),
+    storageParams_
+    (
+        storageParameters::New
+            (mesh_, storageDict_, variablesSet_.allocatedFieldNames())
+    ),
+    adjustTimeStep_(storageParams_->adjustTimeStep()),
+    checkPoints_(),
+    startingTime_(mesh_.time().startTime()),
+    activeCheckPoints_(0),
+    iPtr_(storagePtrs_[0])
+{
+    makeFolder();
+    initialize();
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+Foam::autoPtr<Foam::binomialCheckPointing> Foam::binomialCheckPointing::New
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+{
+    return autoPtr<binomialCheckPointing>
+    (
+        new binomialCheckPointing(primalSolverObj, storageDict)
+    );
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::binomialCheckPointing::scratch()
+{
+    indirectAddressing_ = identity(nCheckPoints_);
+    for (checkPoint& cp : checkPoints_)
+    {
+        cp.empty();
+    }
+    totalSteps_ = 0;
+    recomputationSteps_ = 0;
+    activeCheckPoints_ = 0;
+    storageMetrics_.clear();
+    iPtr_ = -1;
+}
+
+
+void Foam::binomialCheckPointing::storeVariables()
+{
+    label jPtr(0);
+    // Add current to placeholder
+
+    // Find the dispensable checkpoint with the largest time index
+    // idis holds the index of the checkpoint that will be removed.
+    label maxlevel = 0;
+    // Despensable checkpoint index
+    label idis = 0;
+    for (label i = nCheckPoints_ - 1; i >= 1; --i)
+    {
+        if (maxlevel > checkPoints_[indirectAddressing_[i]].level())
+        {
+            // Keep the index only the first time it enters, since it
+            // will have the greater index
+            idis = i;
+            break;
+        }
+        else
+        {
+            maxlevel = checkPoints_[indirectAddressing_[i]].level();
+        }
+    }
+    if (activeCheckPoints_ < nCheckPoints_)
+    {
+        // Scenario 1: not all checkpoints allocated yet.
+        DebugInfo
+            << "Scenario 1" << endl;
+        const label pos = indirectAddressing_[activeCheckPoints_];
+        checkPoints_[pos].setPlaceHolder(false);
+        jPtr = activeCheckPoints_;
+        activeCheckPoints_++;
+    }
+    else if (idis > 0)
+    {
+        // Scenario 2:
+        // at least one checkpoint is despensable. Create a new checkPoint
+        // at the end of the indirect addressing list of level 0.
+        DebugInfo
+            << "Scenario 2" << endl;
+        const label pos = indirectAddressing_[idis];
+        for (label i = idis; i < nCheckPoints_ - 1; ++i)
+        {
+            indirectAddressing_[i] = indirectAddressing_[i + 1];
+        }
+        indirectAddressing_[nCheckPoints_ - 1] = pos;
+        checkPoints_[pos].setPlaceHolder(false);
+        jPtr = nCheckPoints_ - 1;
+    }
+    else
+    {
+        // Scenario 3:
+        // no checkpoint is despensable. Overwrite last checkpoint
+        // and increase its level
+        DebugInfo
+            << "Scenario 3" << endl;
+        const label pos = indirectAddressing_[nCheckPoints_ - 1];
+        checkPoints_[pos].setPlaceHolder(true);
+        jPtr = nCheckPoints_ - 1;
+    }
+
+    // If the previous time-step is in the current set of check-points and
+    // checkpoint is not a placeholder checkpoint store the solution. When
+    // retrieving the solution at scenario 2, the checkpoint is not set as a
+    // placeholder as Wang proposes, so there is no need to store again the
+    // solution in that case.
+    if
+    (
+        (
+            time_.timeIndex() - 1
+         == checkPoints_[indirectAddressing_[jPtr - 1]].timeIndex()
+        )
+     && checkPoints_[indirectAddressing_[jPtr - 1]].placeHolder()
+    )
+    {
+        DebugInfo
+            << "Storing time-step with time, timeIndex = "
+            << name(checkPoints_[indirectAddressing_[jPtr - 1]].timeValue())
+            << " "
+            << checkPoints_[indirectAddressing_[jPtr - 1]].timeIndex()
+            << endl;
+        incompressibleVars& incoVars =
+            refCast<incompressibleVars>(variablesSet_);
+        checkPoints_[indirectAddressing_[jPtr - 1]].store(incoVars);
+    }
+    calcStorageMetrics();
+    ++iPtr_;
+    if (debug)
+    {
+        Info<< "checkPoint time values -->Start<--" << endl;
+        for (label fI = 0; fI < nCheckPoints_; ++fI)
+        {
+            const label pos = indirectAddressing_[fI];
+            Info<< "Checkpoint-ID, indirectAddressing, timeIndex, "
+                << "level, time, placeHolder = "
+                << fI << " "
+                << pos << " "
+                << checkPoints_[pos].timeIndex() << " "
+                << checkPoints_[pos].level() << " "
+                << name(checkPoints_[pos].timeValue()) << " "
+                << checkPoints_[pos].placeHolder() << endl;
+        }
+        Info<< "checkPoint time values --> End <--" << endl;
+    }
+    // Accumulate the primal step to counter
+    totalSteps_++;
+}
+
+
+void Foam::binomialCheckPointing::storeInitialVariables()
+{
+    // Store initial time-step as a placeholder checkPoint of level oo
+    checkPoints_[0].setPlaceHolder(false);
+    checkPoints_[0].level() = pTraits<label>::max;
+    activeCheckPoints_++;
+    ++iPtr_;
+}
+
+
+void Foam::binomialCheckPointing::retrieveVariables()
+{
+    DebugInfo
+        << "Retrieving checkPoint for time " << time_.timeIndex() << endl;
+    dimensionedScalar adjEndingTime = time_.endTime();
+    label timeIndex = time_.timeIndex();
+
+    // Remove the checkpoint if it is at a greater time-step than the current
+    // one, or if it is at the same time-step as the current one, but it is a
+    // placeHolder checkPoint.
+    const label lastPos = indirectAddressing_[activeCheckPoints_ - 1];
+    if
+    (
+        (checkPoints_[lastPos].timeIndex() > timeIndex)
+     || (
+            checkPoints_[lastPos].timeIndex() == timeIndex &&
+            checkPoints_[lastPos].placeHolder()
+        )
+    )
+    {
+        const label pos = indirectAddressing_[activeCheckPoints_ - 1];
+        DebugInfo
+            << "Removing checkPoint: ID, timeIndex, time = " << pos << " "
+            << checkPoints_[pos].timeIndex() << " "
+            << name(checkPoints_[pos].timeValue()) << endl;
+        checkPoints_[pos].empty();
+        activeCheckPoints_--;
+    }
+    Time& time = const_cast<Time&>(time_);
+    if
+    (
+        checkPoints_[indirectAddressing_[activeCheckPoints_ - 1]].timeIndex()
+     == timeIndex
+    )
+    {
+        // Scenario 1:
+        // there is a checkpoint at the current time-step. Retrieve the
+        // solution and make it a placeholder checkpoint
+        DebugInfo
+            << "Scenario 1" << endl;
+        const label pos = indirectAddressing_[activeCheckPoints_ - 1];
+        checkPoints_[pos].retrieve();
+        variablesSet_.validateTurbulence();
+        if (adjustTimeStep_)
+        {
+            time.setDeltaT(checkPoints_[pos].deltaT());
+        }
+        checkPoints_[pos].resetToPlaceHolder();
+        activeCheckPoints_--;
+    }
+    else
+    {
+        // Scenario 2:
+        // there is no checkpoint at the current time-step. Retrieve the
+        // solution at the last checkpoint
+        DebugInfo
+            << "Scenario 2" << endl;
+        const label pos = indirectAddressing_[activeCheckPoints_ - 1];
+
+        scalar nowTime(time.value());
+        if (adjustTimeStep_)
+        {
+            time.setDeltaT(checkPoints_[pos].deltaT());
+        }
+        time.setTime
+            (checkPoints_[pos].timeValue(), checkPoints_[pos].timeIndex());
+        time.setEndTime(nowTime);
+
+        checkPoints_[pos].retrieve();
+        variablesSet_.validateTurbulence();
+
+        while (primalSolver_.loop())
+        {
+            Info<< "Primal-CheckPointing::";
+            primalSolver_.solveIter();
+            recomputationSteps_++;
+        }
+    }
+    time.setEndTime(adjEndingTime);
+    --iPtr_;
+    // Accumulate the adjoint step to counter
+    totalSteps_++;
+}
+
+
+void Foam::binomialCheckPointing::postAdjointLoop()
+{
+    // Output re-computation info
+    scalar recomputationLoad =
+        scalar((2.*recomputationSteps_))/
+        scalar((totalSteps_-recomputationSteps_));
+    Info<<"\n/* * * * * * * * * * * * * * * * * * * * * * * */" << nl
+        <<"Total number of steps "<<totalSteps_ << nl
+        <<"Recomputations        "<<recomputationSteps_ << nl
+        <<"Recomputation load    "<<recomputationLoad << nl
+        <<"/* * * * * * * * * * * * * * * * * * * * * * * */" << nl << endl;
+
+    // Rewind storage pointers with a Warning
+    WarningInFunction
+        << "Rewinding storage pointers, "
+        << "even though check-points have been re-arranged." << nl
+        << "Use binomialCheckPointing with caution in the presence of multiple"
+        << " adjoint solvers"
+        << endl;
+    primalStorage::postAdjointLoop();
+}
+
+
+void Foam::binomialCheckPointing::storageMetrics()
+{
+    gatherMetrics();
+    writeToFile();
+
+    const scalar initialSize = storageMetrics_[0];
+    const scalar uncompressedRoughSize = storageMetrics_[1];
+    const scalar uncompressedSize = storageMetrics_[2];
+    const scalar compressedSize = storageMetrics_[3];
+
+    Info<< nl << "- - - - - - - - - - - - - - - - - - - - -" << endl;
+    Info<< "Primal Storage Statistics" << endl;
+    Info<< "- - - - - - - - - - - - - - - - - - - - -" << nl << endl;
+
+    unsigned int width = 6;//IOstream::defaultPrecision();
+    Info<< setprecision(width);
+    Info<< "nCheckPoints                  = "
+        << activeCheckPoints_ << nl
+        << "Compression Ratio CR_0       = "
+        << uncompressedRoughSize/compressedSize << nl
+        << "ZFP Compression ratio CR_ZFP = "
+        << uncompressedSize/compressedSize << nl
+        << "Initial Size                 = "
+        << initialSize*1.e-6 << " Mb" << nl
+        << "Initial Size Saved           = "
+        << uncompressedRoughSize*1.e-6  << " Mb" << nl
+        << "Compressed Size              = "
+        << compressedSize*1.e-6 << " Mb" << endl;
+    Info<< setprecision(IOstream::defaultPrecision()) << endl;
+    /*
+    Info << "checkPoint time values -->Start<--" << endl;
+    for (label fI=0; fI<nCheckPoints_; fI++)
+    {
+        const label& pos = indirectAddressing_[fI];
+        Info << "Checkpoint-ID, timeIndex, level, time, placeholder = " << fI << " "
+             << checkPoints_[pos].timeIndex() << " " << checkPoints_[pos].level()
+             << " " << ::Foam::name(checkPoints_[pos].timeValue()) << " "
+             << checkPoints_[pos].placeHolder() << endl;
+    }
+    Info << "checkPoint time values --> End <--" << endl;
+    */
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/binomialCheckPointing/binomialCheckPointing.H

@@ -0,0 +1,224 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::binomialCheckPointing
+
+Description
+    Class implementing the binomial check-pointing technique for the unsteady
+    adjoint optimisation
+
+SourceFiles
+    binomialCheckPointing.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef binomialCheckPointing_H
+#define binomialCheckPointing_H
+
+#include "primalStorage.H"
+#include "storageParameters.H"
+#include "runTimeSelectionTables.H"
+#include "OFstream.H"
+#include "checkPoint.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                    Class binomialCheckPointing Declaration
+\*---------------------------------------------------------------------------*/
+
+class binomialCheckPointing
+:
+    public primalStorage
+{
+
+protected:
+
+    // Protected Data
+
+        //- Counter of the total number of time-steps performed to
+        //- complete the optimization cycle
+        //  primal + adjoint + primal recomputations due to checkPointing
+        label totalSteps_;
+
+        //- Counter of the number of recomputation time-steps
+        //- performed to complete the optimization cycle
+        label recomputationSteps_;
+
+        //- Storage parameters
+        autoPtr<storageParameters> storageParams_;
+
+        //- Reseting deltaT causes slight disrepancies in comparison to the
+        //- solution of shortFullStorage.
+        //  Reseting applied only with non-constant time-step. Entry taken from
+        //  storageParameters to avoid the possibility of the user changing
+        //  runTime the adjustTimeStep of controlDict
+        const Switch& adjustTimeStep_;
+
+        //- Number of chechPoints to be stored
+        label nCheckPoints_;
+
+        //- Accumulated storage metrics
+        scalarList storageMetrics_;
+
+        //- All stored checkPoints
+        PtrList<checkPoint> checkPoints_;
+
+        //- Position of each checkPoint, as stored in chronological order,
+        //- in the checkPoints list
+        List<label> indirectAddressing_;
+
+        dimensionedScalar startingTime_;
+
+        label activeCheckPoints_;
+
+        label& iPtr_;
+
+        mutable autoPtr<OFstream> metricsFilePtr_;
+
+        mutable autoPtr<OFstream> checkPointsFilePtr_;
+
+
+    // Protected Member Functions
+
+        //- Gather metrics from all processors if timing == true.
+        //  If timing == false, the reduce operation has already been deployed.
+        void gatherMetrics();
+
+        //- Set file to write metrics - one line for each optimisation cycle
+        void setMetricsFilesPtr();
+
+        //- Set file to write checkPoints
+        void setCheckPointsFilesPtr();
+
+        inline void writeToFile();
+
+        //- Calculates the compression metrics of the whole primal solution
+        virtual void calcStorageMetrics();
+
+        //- Start process for each host
+        labelList hostStartProcess(wordList& hostNames) const;
+
+        //- Get checkpoint size. The size of the first checkpoint size is not
+        //- dependable, since it may include only the fields of the current
+        //- time-step and not the oldTimes.  Instead, we solve for one
+        //- time-step and use its size as a reference
+        scalar checkPointSize();
+
+        //- Print checkpoint size and estimate number of checkpoints that
+        //- can be allocated based on the available memory at run time
+        unsigned long long maxNumberOfCheckPoints();
+
+        void initialize();
+
+
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        binomialCheckPointing(const binomialCheckPointing&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const binomialCheckPointing&) = delete;
+
+
+public:
+
+    TypeName("binomialCheckPointing");
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            binomialCheckPointing,
+            dictionary,
+            (
+                primalSolver& primalSolverObj,
+                const dictionary storageDict
+            ),
+            (primalSolverObj, storageDict)
+        );
+
+
+    // Constructors
+
+        //- Construct from components
+        binomialCheckPointing
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    // Selectors
+
+        //- Allocate new binomialCheckPointing
+        static autoPtr<binomialCheckPointing> New
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    //- Destructor
+    virtual ~binomialCheckPointing() = default;
+
+
+    // Member functions
+
+        //- Release all checkpoints
+        virtual void scratch() override;
+
+        //- Store current variable set as a checkpoint if needed
+        virtual void storeVariables() override;
+
+        virtual void storeInitialVariables() override;
+
+        virtual void retrieveVariables() override;
+
+        //- Operations performed after the end of the adjoint loop
+        virtual void postAdjointLoop() override;
+
+        //- Function to write the storage metrics of the whole primal solution
+        virtual void storageMetrics() override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/compressedFullStorage/compressedFullStorage/compressedFullStorage.C

@@ -0,0 +1,150 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "compressedFullStorage.H"
+#include "compressedIncompressibleVars.H"
+#include "memInfo.H"
+#include "addToRunTimeSelectionTable.H"
+#include "IOmanip.H"
+
+// * * * * * * * * * * * * * Static Member Data  * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(compressedFullStorage, 0);
+    defineRunTimeSelectionTable(compressedFullStorage, dictionary);
+    addToRunTimeSelectionTable
+    (
+        primalStorage,
+        compressedFullStorage,
+        primalStorage
+    );
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::compressedFullStorage::compressedFullStorage
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+:
+    primalStorage(primalSolverObj, storageDict),
+    allPrimalVars_(0),
+    storageMetrics_(),
+    totalSteps_(0),
+    recomputationSteps_(0),
+    metricsFilePtr_()
+{
+    makeFolder();
+    storageParams_.reset
+    (
+        storageParameters::New
+        (
+            mesh_,
+            storageDict_,
+            variablesSet_.allocatedFieldNames()
+        )
+    );
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+Foam::autoPtr<Foam::compressedFullStorage> Foam::compressedFullStorage::New
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+{
+    const dictionary& dict = storageDict.subDict("storageParameters");
+    const word type(dict.get<word>("algorithm") + "FullStorage");
+    Info<< "CompressedFullStorage type" << tab << type << endl;
+
+    auto* ctorPtr = dictionaryConstructorTable(type);
+
+    if (!ctorPtr)
+    {
+        FatalIOErrorInLookup
+        (
+            storageDict,
+            "compressedFullStorage",
+            type,
+            *dictionaryConstructorTablePtr_
+        ) << exit(FatalIOError);
+    }
+
+    return autoPtr<compressedFullStorage>
+        (ctorPtr(primalSolverObj, storageDict));
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::compressedFullStorage::scratch()
+{
+    NotImplemented
+}
+
+
+void Foam::compressedFullStorage::storeVariables()
+{
+    NotImplemented
+}
+
+
+void Foam::compressedFullStorage::retrieveVariables()
+{
+    NotImplemented
+}
+
+
+void Foam::compressedFullStorage::postAdjointLoop()
+{
+    scalar recomputationLoad =
+        scalar((2.*recomputationSteps_))/
+        scalar((totalSteps_-recomputationSteps_));
+    Info<<"\n/* * * * * * * * * * * * * * * * * * * * * * * */\n"
+        <<"Total number of steps "<<totalSteps_ << nl
+        <<"Recomputations        "<<recomputationSteps_ << nl
+        <<"Recomputation load    "<<recomputationLoad << nl
+        <<"/* * * * * * * * * * * * * * * * * * * * * * * */\n" << endl;
+
+    // Rewind storage ptrs
+    primalStorage::postAdjointLoop();
+}
+
+
+void Foam::compressedFullStorage::storageMetrics()
+{
+    NotImplemented
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/compressedFullStorage/compressedFullStorage/compressedFullStorage.H

@@ -0,0 +1,165 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::compressedFullStorage
+
+Description
+    Compresses and stores all instances of the primal flow fields
+
+SourceFiles
+    compressedFullStorage.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef compressedFullStorage_H
+#define compressedFullStorage_H
+
+#include "primalStorage.H"
+#include "compressedIncompressibleVars.H"
+#include "storageParameters.H"
+#include "runTimeSelectionTables.H"
+#include "OFstream.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                    Class compressedFullStorage Declaration
+\*---------------------------------------------------------------------------*/
+
+class compressedFullStorage
+:
+    public primalStorage
+{
+protected:
+
+    // Protected Data
+
+        PtrList<compressedIncompressibleVars> allPrimalVars_;
+
+        scalarList storageMetrics_;
+
+        //- Counter of the total number of time-steps performed to
+        //- complete the optimization cycle.
+        //  Equal to primal + adjoint + primal recomputations
+        //  in case of checkPointing strategies
+        label totalSteps_;
+
+        //- Counter of the number of recomputation time-steps
+        //- performed to complete the optimization cycle
+        label recomputationSteps_;
+
+        //- Storage parameters
+        autoPtr<storageParameters> storageParams_;
+
+        mutable autoPtr<OFstream> metricsFilePtr_;
+
+
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        compressedFullStorage(const compressedFullStorage&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const compressedFullStorage&) = delete;
+
+
+public:
+
+    TypeName("compressedFullStorage");
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            compressedFullStorage,
+            dictionary,
+            (
+                primalSolver& primalSolverObj,
+                const dictionary storageDict
+            ),
+            (primalSolverObj, storageDict)
+        );
+
+
+    // Constructors
+
+        //- Construct from components
+        compressedFullStorage
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    // Selectors
+
+        //- Return a reference to the selected turbulence model
+        static autoPtr<compressedFullStorage> New
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    //- Destructor
+    virtual ~compressedFullStorage() = default;
+
+
+    // Member functions
+
+        //- Free memory used to store the primal time-series
+        virtual void scratch() override;
+
+        //- Store current copy of the variablesSet (could be lossy)
+        virtual void storeVariables() override;
+
+        //- Retrieve primal-based quantities into the active variablesSet
+        virtual void retrieveVariables() override;
+
+        //- Operations performed after the end of the adjoint loop
+        virtual void postAdjointLoop() override;
+
+        //- Function to write the storage metrics of the whole primal solution
+        virtual void storageMetrics() override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/compressedFullStorage/shortFullStorage/shortFullStorage.C

@@ -0,0 +1,236 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "primalSolver.H"
+#include "shortFullStorage.H"
+#include "memInfo.H"
+#include "addToRunTimeSelectionTable.H"
+#include "IOmanip.H"
+
+// * * * * * * * * * * * * * Static Member Data  * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(shortFullStorage, 0);
+    addToRunTimeSelectionTable
+    (
+        compressedFullStorage,
+        shortFullStorage,
+        dictionary
+    );
+}
+
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::shortFullStorage::gatherMetrics()
+{
+    if (storageParams_().timing())
+    {
+        for (scalar& storageMetric : storageMetrics_)
+        {
+            reduce(storageMetric, sumOp<scalar>());
+        }
+    }
+}
+
+
+void Foam::shortFullStorage::setMetricsFilesPtr()
+{
+    fileName filePath =
+        storageFolder_/"AllOptCycles" + primalSolver_.solverName();
+    if (!isFile(filePath))
+    {
+        DebugInfo
+            << "Creating file: " << filePath << endl;
+        metricsFilePtr_.reset(new OFstream(filePath));
+        if (!metricsFilePtr_()())
+        {
+            FatalErrorInFunction
+                << "Stream has failed." << endl
+                << exit(FatalError);
+        }
+        if (!isFile(filePath))
+        {
+            FatalErrorInFunction
+                << "Error while creating file: " << filePath << endl
+                << exit(FatalError);
+        }
+        unsigned int width = IOstream::defaultPrecision() + 6;
+        metricsFilePtr_()
+            << setw(width) << "Initial Size (Mb)" << tab
+            << setw(width) << "Initial Size Saved (Mb)" << endl;
+    }
+    else
+    {
+        metricsFilePtr_.reset
+        (
+            new OFstream
+                (
+                    filePath,
+                    IOstream::ASCII,
+                    IOstream::currentVersion,
+                    IOstream::UNCOMPRESSED,
+                    true
+                )
+        );
+    }
+}
+
+
+inline void Foam::shortFullStorage::writeToFile()
+{
+    if (Pstream::master())
+    {
+        if (!metricsFilePtr_)
+        {
+            setMetricsFilesPtr();
+        }
+        const scalar initialSize = storageMetrics_[0];
+        const scalar uncompressedRoughSize = storageMetrics_[1];
+        unsigned int width = IOstream::defaultPrecision() + 6;
+        metricsFilePtr_()
+            << setprecision(IOstream::defaultPrecision());
+        metricsFilePtr_() << setw(width) << initialSize*1.e-6 << tab
+            << setw(width) << uncompressedRoughSize*1.e-6 << endl;
+    }
+}
+
+
+void Foam::shortFullStorage::calcStorageMetrics()
+{
+    const scalarList& metrics = allPrimalVars_[iPtr_].storageMetrics();
+    if (allPrimalVars_.size() == 1)
+    {
+        storageMetrics_ = metrics;
+    }
+    else
+    {
+        storageMetrics_ = storageMetrics_ + metrics;
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::shortFullStorage::shortFullStorage
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+:
+    compressedFullStorage(primalSolverObj, storageDict),
+    iPtr_(storagePtrs_[0])
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::shortFullStorage::scratch()
+{
+    totalSteps_ = 0;
+    iPtr_ = -1;
+    allPrimalVars_.clear();
+    storageMetrics_.clear();
+}
+
+
+void Foam::shortFullStorage::storeVariables()
+{
+    if (allPrimalVars_.size() > iPtr_ + 1)
+    {
+        Info<< endl;
+        WarningInFunction
+            << tab
+            << "allPrimalVars.size(), iPtr = "
+            << allPrimalVars_.size() << " " << iPtr_
+            << nl << tab
+            << "Normally, allPrimalVars.size() = iPtr + 1 in each time step"
+            << nl << tab
+            << "Possible cause: Multiple compressions/decompressions "
+            << "of the same time step"
+            << nl << tab
+            << "allPrimalVars.size() manually set to "
+            << iPtr_ + 1 << nl << endl;
+        allPrimalVars_.resize(iPtr_ + 1);
+    }
+    incompressibleVars& incoVars = refCast<incompressibleVars>(variablesSet_);
+    autoPtr<compressedIncompressibleVars> varsPtr
+    (
+        compressedIncompressibleVars::New
+        (
+            incoVars,
+            storageParams_()
+        )
+    );
+    varsPtr->compress();
+    varsPtr->calculateStorageMetrics();
+    allPrimalVars_.append(varsPtr);
+    ++iPtr_;
+    calcStorageMetrics();
+    // Accumulate the primal step to counter
+    totalSteps_++;
+}
+
+
+void Foam::shortFullStorage::retrieveVariables()
+{
+    if (allPrimalVars_.empty())
+    {
+        FatalErrorInFunction
+            << "allPrimalVars_ list is empty." << endl
+            << exit(FatalError);
+    }
+    allPrimalVars_[iPtr_].decompress();
+    variablesSet_.validateTurbulence();
+    --iPtr_;
+    // Accumulate the adjoint step to counter
+    totalSteps_++;
+}
+
+
+void Foam::shortFullStorage::storageMetrics()
+{
+    gatherMetrics();
+    writeToFile();
+
+    const scalar initialSize = storageMetrics_[0];
+    const scalar uncompressedRoughSize = storageMetrics_[1];
+
+    Info<< nl << "- - - - - - - - - - - - - - - - - - - - -" << endl;
+    Info<< "Primal Storage Statistics" << endl;
+    Info<< "- - - - - - - - - - - - - - - - - - - - -" << nl << endl;
+
+    Info<< setprecision(6);
+    Info<< "Initial Size = " << initialSize*1.e-6 << " Mb" << endl;
+    Info<< "Stored Size  = " << uncompressedRoughSize*1.e-6  << " Mb" << endl;
+    Info<< setprecision(IOstream::defaultPrecision()) << endl;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/compressedFullStorage/shortFullStorage/shortFullStorage.H

@@ -0,0 +1,135 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::shortFullStorage
+
+Description
+    Stores all instances of the primal flow fields.
+    In constrast to full storage, parts of the fields that can be recomputed
+    (fixedValue boundary conditions, processor values etc) are not stored,
+    reducing slightly the memory footprint
+
+SourceFiles
+    shortFullStorage.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef shortFullStorage_H
+#define shortFullStorage_H
+
+#include "compressedFullStorage.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                        Class shortFullStorage Declaration
+\*---------------------------------------------------------------------------*/
+
+class shortFullStorage
+:
+    public compressedFullStorage
+{
+protected:
+
+    // Protected Data
+
+        label& iPtr_;
+
+
+    // Protected Member Functions
+
+        //- Gather metrics from all processors if timing == true.
+        //  If timing == false, the reduce operation has already been deployed.
+        void gatherMetrics();
+
+        //- Set file to write metrics - one line per optimisation cycle
+        void setMetricsFilesPtr();
+
+        inline void writeToFile();
+
+        //- Function to calculate the compression metrics of the whole primal
+        //- solution
+        void calcStorageMetrics();
+
+
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        shortFullStorage(const shortFullStorage&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const shortFullStorage&) = delete;
+
+
+public:
+
+    TypeName("shortFullStorage");
+
+    // Constructors
+
+        //- Construct from components
+        shortFullStorage
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    //- Destructor
+    virtual ~shortFullStorage() = default;
+
+
+    // Member functions
+
+        //- Free memory used to store the primal time-series
+        virtual void scratch() override;
+
+        //- Store current copy of the variablesSet (could be lossy)
+        virtual void storeVariables() override;
+
+        //- Retrieve primal-based quantities into the active variablesSet
+        virtual void retrieveVariables() override;
+
+        //- Function to write the storage metrics of the whole primal solution
+        void storageMetrics() override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/fullStorage/fullStorage.C

@@ -0,0 +1,235 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "fullStorage.H"
+#include "memInfo.H"
+#include "addToRunTimeSelectionTable.H"
+#include "IOmanip.H"
+
+// * * * * * * * * * * * * * Static Member Data  * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(fullStorage, 0);
+    defineRunTimeSelectionTable(fullStorage, dictionary);
+    addToRunTimeSelectionTable(primalStorage, fullStorage, primalStorage);
+}
+
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+Foam::labelList Foam::fullStorage::hostStartProcess(wordList& hostNames) const
+{
+    // Gather host names for all processors
+    wordList machineName(Pstream::nProcs());
+    machineName[Pstream::myProcNo()] = hostName();
+    Pstream::gatherList(machineName);
+    Pstream::scatterList(machineName);
+    hostNames = machineName;
+
+    // Start process ID for each host; to be resized
+    const label nProcs(Pstream::nProcs());
+    labelList hostStartProcess(nProcs + 1, 0);
+
+    label iHost(0);
+    word prev(word::null);
+    for (label procI = 0; procI < nProcs; ++procI)
+    {
+        if (machineName[procI] != prev)
+        {
+            hostStartProcess[iHost] = procI;
+            prev = machineName[procI];
+            ++iHost;
+        }
+    }
+    // Allocate an additional entry for easy looping over start
+    // of this host and the next one
+    hostStartProcess.setSize(iHost + 1);
+    hostStartProcess[iHost] = nProcs;
+    return hostStartProcess;
+}
+
+
+Foam::label Foam::fullStorage::maxNumberOfInstances() const
+{
+    // Find instance size per processor
+    labelList sizeBef(Pstream::nProcs());
+    sizeBef[Pstream::myProcNo()] = memInfo().size();
+    Pstream::gatherList(sizeBef);
+    Pstream::scatterList(sizeBef);
+
+    autoPtr<variablesSet> temp(variablesSet_.clone());
+
+    labelList sizeAft(Pstream::nProcs());
+    sizeAft[Pstream::myProcNo()] = memInfo().size();
+    Pstream::gatherList(sizeAft);
+    Pstream::scatterList(sizeAft);
+
+    // Available memory. Is stored on a per-processor base but actually
+    // refers to the host. Use with caution
+    labelList free(Pstream::nProcs());
+    free[Pstream::myProcNo()] = memInfo().free();
+    Pstream::gatherList(free);
+    Pstream::scatterList(free);
+
+    // Host name, per processor basis
+    wordList hostNames(0);
+    // Start process ID per host
+    labelList hostStartProcessID(hostStartProcess(hostNames));
+    label nHosts(hostStartProcessID.size() - 1);
+
+    // Determine the number of instances that can be allocated as the
+    // minimum from all hosts
+    labelList hostInstanceSize(nHosts, 0);
+    label nInstances(pTraits<label>::max);
+    label limitingHostID(-1);
+    for (label iHost = 0; iHost < nHosts; ++iHost)
+    {
+        const label start(hostStartProcessID[iHost]);
+        const label end(hostStartProcessID[iHost + 1]);
+        label& hostSize = hostInstanceSize[iHost];
+        for (label procI = start; procI < end; ++procI)
+        {
+            hostSize += sizeAft[procI] - sizeBef[procI];
+        }
+        label nHostCheckPoints(free[start]/hostSize);
+        if (nHostCheckPoints < nInstances)
+        {
+            nInstances = nHostCheckPoints;
+            limitingHostID = iHost;
+        }
+    }
+
+    // Print global instance size
+    const label checkPointSize(sum(sizeAft) - sum(sizeBef));
+    Info<< nl << "Global size of an instance is "
+        << checkPointSize << " KBs" << endl;
+
+    // Print max number of check points that fit in the most limiting host
+    Info<< "Approximately " << nInstances
+        << " instances can be stored, "
+        << "without accounting for cached memory " << endl;
+
+    // Print information on a per host basis
+    if (debug > 1)
+    {
+        Info<< nl
+            << setw(23) << "Host" << " | "
+            << setw(23) << "Instance size (kBs)" << " | "
+            << setw(23) << "Available memory (kBs)" << " | "
+            << setw(23) << "Max checkpoints (local)"
+            << nl;
+        for (label iHost = 0; iHost < nHosts; ++iHost)
+        {
+            const label start(hostStartProcessID[iHost]);
+            Info<< setw(23) << hostNames[start] << "   "
+                << setw(23) << hostInstanceSize[iHost] << "   "
+                << setw(23) << free[start] << "   "
+                << setw(23) << free[start]/hostInstanceSize[iHost]
+                << endl;
+        }
+        Info<< endl;
+    }
+
+    string limitingHost;
+    if (Pstream::myProcNo() == hostStartProcessID[limitingHostID])
+    {
+        limitingHost = hostName();
+    }
+    reduce(limitingHost, sumOp<word>());
+    Info<< "Limiting factor is host " << limitingHost << nl << endl;
+
+    return nInstances;
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::fullStorage::fullStorage
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+:
+    primalStorage(primalSolverObj, storageDict),
+    allPrimalVars_(0),
+    iPtr_(storagePtrs_[0])
+{
+    /*if (debug)
+    {
+        maxNumberOfCheckPoints();
+    }*/
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+Foam::autoPtr<Foam::fullStorage> Foam::fullStorage::New
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+{
+    return autoPtr<fullStorage>
+    (
+        new fullStorage(primalSolverObj, storageDict)
+    );
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::fullStorage::scratch()
+{
+    allPrimalVars_.clear();
+    iPtr_ = -1;
+}
+
+
+void Foam::fullStorage::storeVariables()
+{
+    allPrimalVars_.append(variablesSet_.clone());
+    ++iPtr_;
+}
+
+
+void Foam::fullStorage::retrieveVariables()
+{
+    if (allPrimalVars_.empty())
+    {
+        FatalErrorInFunction
+            << "allPrimalVars list is empty." << endl
+            << exit(FatalError);
+    }
+    variablesSet_.transfer(allPrimalVars_[iPtr_]);
+    //allPrimalVars_.release(iPtr_);
+    --iPtr_;
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/fullStorage/fullStorage.H

@@ -0,0 +1,150 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::fullStorage
+
+Description
+    Stores all instances of the primal flow fields.
+    Can lead to huge memory requirements if used with large meshes and many
+    time-steps
+
+SourceFiles
+    fullStorage.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef fullStorage_H
+#define fullStorage_H
+
+#include "primalStorage.H"
+#include "runTimeSelectionTables.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                         Class fullStorage Declaration
+\*---------------------------------------------------------------------------*/
+
+class fullStorage
+:
+    public primalStorage
+{
+protected:
+
+    // Protected Data
+
+        PtrList<variablesSet> allPrimalVars_;
+
+        label& iPtr_;
+
+
+    // Protected Member Functions
+
+        //- Start process for each host
+        labelList hostStartProcess(wordList& hostNames) const;
+
+        //- Print time instance size and estimate number of instances that
+        //- can be allocated based on the available memory at run time
+        label maxNumberOfInstances() const;
+
+
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        fullStorage(const fullStorage&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const fullStorage&) = delete;
+
+
+public:
+
+    TypeName("fullStorage");
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            fullStorage,
+            dictionary,
+            (
+                primalSolver& primalSolverObj,
+                const dictionary storageDict
+            ),
+            (primalSolverObj, storageDict)
+        );
+
+
+    // Constructors
+
+        //- Construct from components
+        fullStorage
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    // Selectors
+
+        //- Return a reference to the selected turbulence model
+        static autoPtr<fullStorage> New
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    //- Destructor
+    virtual ~fullStorage() = default;
+
+
+    // Member functions
+
+        virtual void scratch() override;
+
+        virtual void storeVariables() override;
+
+        virtual void retrieveVariables() override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/none/noneStorage.C

@@ -0,0 +1,89 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "noneStorage.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * Static Member Data  * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(noneStorage, 0);
+    defineRunTimeSelectionTable(noneStorage, dictionary);
+    addToRunTimeSelectionTable(primalStorage, noneStorage, primalStorage);
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::noneStorage::noneStorage
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+:
+    primalStorage(primalSolverObj, storageDict)
+{}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+Foam::autoPtr<Foam::noneStorage> Foam::noneStorage::New
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+{
+    return autoPtr<noneStorage>
+    (
+        new noneStorage(primalSolverObj, storageDict)
+    );
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::noneStorage::scratch()
+{
+    // Does nothing
+}
+
+
+void Foam::noneStorage::storeVariables()
+{
+    // Does nothing
+}
+
+
+void Foam::noneStorage::retrieveVariables()
+{
+    // Does nothing
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/none/noneStorage.H

@@ -0,0 +1,130 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::noneStorage
+
+Description
+    A primalStorage instance doing nothing. Used, for instance, with steady
+    state simulations
+
+SourceFiles
+    noneStorage.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef noneStorage_H
+#define noneStorage_H
+
+#include "primalStorage.H"
+#include "runTimeSelectionTables.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                        Class noneStorage Declaration
+\*---------------------------------------------------------------------------*/
+
+class noneStorage
+:
+    public primalStorage
+{
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        noneStorage(const noneStorage&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const noneStorage&) = delete;
+
+
+public:
+
+    TypeName("none");
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            noneStorage,
+            dictionary,
+            (
+                primalSolver& primalSolverObj,
+                const dictionary storageDict
+            ),
+            (primalSolverObj, storageDict)
+        );
+
+
+    // Constructors
+
+        //- Construct from components
+        noneStorage
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    // Selectors
+
+        //- Return a reference to the selected turbulence model
+        static autoPtr<noneStorage> New
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    //- Destructor
+    virtual ~noneStorage() = default;
+
+
+    // Member functions
+
+        virtual void scratch() override;
+
+        virtual void storeVariables() override;
+
+        virtual void retrieveVariables() override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/primalStorage/primalStorage.C

@@ -0,0 +1,170 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "error.H"
+#include "primalStorage.H"
+#include "primalSolver.H"
+
+// * * * * * * * * * * * * * Static Member Data  * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(primalStorage, 0);
+    defineRunTimeSelectionTable(primalStorage, primalStorage);
+
+    label primalStorage::counter = 0;
+}
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::primalStorage::makeFolder()
+{
+    if (Pstream::master())
+    {
+        storageFolder_ = time_.globalPath()/"optimisation"/"storage";
+        //- do not remove directory to allow for continuation
+        //if (isDir(storageFolder_)) rmDir(storageFolder_);
+        mkDir(storageFolder_);
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::primalStorage::primalStorage
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+:
+    time_(primalSolverObj.mesh().time()),
+    mesh_(primalSolverObj.mesh()),
+    primalSolver_(primalSolverObj),
+    storageDict_(storageDict),
+    variablesSet_(primalSolver_.getVariablesSet()),
+    storagePtrs_(1, -1),
+    storagePtrsCopy_(nullptr)
+{
+    if (Pstream::master())
+    {
+        counter++;
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+Foam::autoPtr<Foam::primalStorage> Foam::primalStorage::New
+(
+    primalSolver& primalSolverObj,
+    const dictionary storageDict
+)
+{
+    const word type(storageDict.get<word>("type"));
+    Info<< "Storage type for the primal fields: " << type << endl;
+
+    auto* ctorPtr = primalStorageConstructorTable(type);
+
+    if (!ctorPtr)
+    {
+        FatalIOErrorInLookup
+        (
+            storageDict,
+            "primalStorage",
+            type,
+            *primalStorageConstructorTablePtr_
+        ) << exit(FatalIOError);
+    }
+
+    return autoPtr<primalStorage>(ctorPtr(primalSolverObj, storageDict));
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+const Foam::labelList& Foam::primalStorage::storagePtrs() const
+{
+    return storagePtrs_;
+}
+
+
+void Foam::primalStorage::copyStoragePtrs()
+{
+    storagePtrsCopy_.reset(new labelList(storagePtrs_));
+}
+
+
+void Foam::primalStorage::rewindStoragePtrs()
+{
+    if (storagePtrsCopy_)
+    {
+        storagePtrs_ = storagePtrsCopy_();
+    }
+    else
+    {
+        FatalErrorInFunction
+            << "Attempted to retrieve unset storePtrs" << endl;
+    }
+}
+
+
+void Foam::primalStorage::storeInitialVariables()
+{
+    // Does nothing in base
+}
+
+
+void Foam::primalStorage::preLoopRetrieveVariables()
+{
+    // Does nothing in base
+}
+
+
+void Foam::primalStorage::preAdjointLoop()
+{
+    // Copy pointers to storage instances to a backup variable
+    copyStoragePtrs();
+    // Retrive certain variables before the adjoint loop
+    // (e.g. from files, for restarted cases)
+    preLoopRetrieveVariables();
+}
+
+
+void Foam::primalStorage::postAdjointLoop()
+{
+    rewindStoragePtrs();
+}
+
+
+void Foam::primalStorage::storageMetrics()
+{
+    // Does nothing in base
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/primalStorage/primalStorage.H

@@ -0,0 +1,203 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::primalStorage
+
+Description
+    Abstract base class managing the storage of primal flow fields, to be later
+    used for the solution of unsteady flow equations
+
+SourceFiles
+    primalStorage.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef primalStorage_H
+#define primalStorage_H
+
+#include "Time.H"
+#include "fvMesh.H"
+#include "dictionary.H"
+#include "variablesSet.H"
+#include "runTimeSelectionTables.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+
+namespace Foam
+{
+
+// Forward declaratrions
+class primalSolver;
+
+/*---------------------------------------------------------------------------*\
+                        Class primalStorage Declaration
+\*---------------------------------------------------------------------------*/
+
+class primalStorage
+{
+    static label counter;
+
+protected:
+
+    // Protected Data
+
+        //- Const reference to time
+        const Time& time_;
+
+        //- Const reference to mesh
+        const fvMesh& mesh_;
+
+        //- Reference to the primal solver used to create the time-series
+        //- being stored
+        primalSolver& primalSolver_;
+
+        //- Input dict
+        dictionary storageDict_;
+
+        //- Variables set of the primal solver
+        variablesSet& variablesSet_;
+
+        //- List of useful pointers in the flow time-series
+        //  For instance, time-steps holding checkpoints, etc
+        labelList storagePtrs_;
+
+        //- Copy of the pointer's list
+        //  Usefull for reseting in many of many primal solvers
+        autoPtr<labelList> storagePtrsCopy_;
+
+        //- Output folder
+        fileName storageFolder_;
+
+
+    // Protected Member Functions
+
+        //- Set Folder
+        virtual void makeFolder();
+
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        primalStorage(const primalStorage&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const primalStorage&) = delete;
+
+
+public:
+
+    TypeName("primalStorage");
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeNewSelectionTable
+        (
+            autoPtr,
+            primalStorage,
+            primalStorage,
+            (
+                primalSolver& primalSolverObj,
+                const dictionary storageDict
+            ),
+            (primalSolverObj, storageDict)
+        );
+
+
+    // Constructors
+
+        //- Construct from components
+        primalStorage
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    // Selectors
+
+        //- Return a reference to the selected turbulence model
+        static autoPtr<primalStorage> New
+        (
+            primalSolver& primalSolverObj,
+            const dictionary storageDict
+        );
+
+
+    // Destructor
+
+        //- Virtual destructor
+        virtual ~primalStorage() = default;
+
+
+    // Member functions
+
+        //- Get list with pointers to storage instances
+        virtual const labelList& storagePtrs() const;
+
+        //- Copy pointers to storage instances to a backup variable
+        virtual void copyStoragePtrs();
+
+        //- Rewind pointers to storage instance to the values set after the
+        //- solution of the primal equations
+        virtual void rewindStoragePtrs();
+
+        //- Free memory used to store the primal time-series
+        virtual void scratch() = 0;
+
+        //- Store current copy of the variablesSet (could be lossy)
+        virtual void storeVariables() = 0;
+
+        virtual void storeInitialVariables();
+
+        //- Retrieve primal-based quantities into the active variablesSet
+        virtual void retrieveVariables() = 0;
+
+        //- Retrive certain variables before the adjoint loop
+        //  (e.g. from files, for restarted cases)
+        virtual void preLoopRetrieveVariables();
+
+        //- Operations performed before the beginning of the adjoint loop
+        virtual void preAdjointLoop();
+
+        //- Operations performed after the end of the adjoint loop
+        virtual void postAdjointLoop();
+
+        virtual void storageMetrics();
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/storageParameters/shortParameters/shortParameters.C

@@ -0,0 +1,68 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "shortParameters.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(shortParameters, 0);
+    addToRunTimeSelectionTable(storageParameters, shortParameters, dictionary);
+}
+
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void Foam::shortParameters::initialize()
+{
+    compressionMethod_.setSize(allocatedFieldNames_.size());
+    forAll(allocatedFieldNames_, iPtr)
+    {
+        compressionMethod_[iPtr] = algorithm_ + "GeometricField";
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::shortParameters::shortParameters
+(
+    const fvMesh& mesh,
+    const dictionary& storageDict,
+    const wordList& allocatedFieldNames
+)
+:
+    storageParameters(mesh, storageDict, allocatedFieldNames)
+{
+    initialize();
+}
+
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/storageParameters/shortParameters/shortParameters.H

@@ -0,0 +1,101 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    shortParameters
+
+Description
+    Reads from dictionary and stores all parameters related to the storage
+    of the primal fields
+
+SourceFiles
+    shortParameters.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef shortParameters_H
+#define shortParameters_H
+
+#include "storageParameters.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                        Class shortParameters Declaration
+\*---------------------------------------------------------------------------*/
+
+class shortParameters
+:
+    public storageParameters
+{
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        shortParameters(const shortParameters&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const shortParameters&) = delete;
+
+
+public:
+
+    TypeName("shortParameters");
+
+    // Constructors
+
+        //- Construct from components
+        shortParameters
+        (
+            const fvMesh& mesh,
+            const dictionary& storageDict,
+            const wordList& allocatedFieldNames
+        );
+
+
+    //- Destructor
+    virtual ~shortParameters() = default;
+
+
+    // Member functions
+
+        virtual void initialize() override;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/storageParameters/storageParameters/storageParameters.C

@@ -0,0 +1,213 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "Ostream.H"
+#include "storageParameters.H"
+#include "wallFvPatch.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+defineTypeNameAndDebug(storageParameters, 0);
+defineRunTimeSelectionTable(storageParameters, dictionary);
+
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+label storageParameters::counter = 0;
+
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+void storageParameters::findCellsNextToWall()
+{
+    // Find the boundary patches that are of type wall
+    const fvPatchList& patches = mesh_.boundary();
+    DynamicList<label> patchList;
+    label size(0);
+    forAll(patches, patchI)
+    {
+        const fvPatch& patch = mesh_.boundary()[patchI];
+        if (isA<wallFvPatch>(patch))
+        {
+            patchList.append(patchI);
+            size += patch.faceCells().size();
+        }
+    }
+    // Build list containing the IDs of the first cell centers next to wall
+    // boundaries
+    wallList_.setSize(size, -1);
+    label pos(0);
+    forAll(patchList, patchI)
+    {
+        const fvPatch& patch = mesh_.boundary()[patchList[patchI]];
+        forAll(patch, faceI)
+        {
+            wallList_[pos++] = patch.faceCells()[faceI];
+        }
+    }
+    Info<< "Found " << patchList.size() << " wall boundary(ies) "
+        << "with total " << returnReduce(wallList_.size(), sumOp<label>())
+        << " cells next to them." << endl;
+}
+
+
+// * * * * * * * * * * * * * * * * * Selectors * * * * * * * * * * * * * * * //
+
+autoPtr<storageParameters> storageParameters::New
+(
+    const fvMesh& mesh,
+    const dictionary& storageDict,
+    const wordList& allocatedFieldNames
+)
+{
+    const dictionary& dict = storageDict.subDict("storageParameters");
+    const word type(dict.get<word>("algorithm") + "Parameters" );
+    Info<< "Compression parameters type" << tab << type << endl;
+
+    auto* ctorPtr = dictionaryConstructorTable(type);
+
+    if (!ctorPtr)
+    {
+        FatalIOErrorInLookup
+        (
+            storageDict,
+            "storageParameters",
+            type,
+            *dictionaryConstructorTablePtr_
+        ) << exit(FatalIOError);
+    }
+
+    return autoPtr<storageParameters>
+        (ctorPtr(mesh, storageDict, allocatedFieldNames));
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+storageParameters::storageParameters
+(
+    const fvMesh& mesh,
+    const dictionary& storageDict,
+    const wordList& allocatedFieldNames
+)
+:
+    mesh_(mesh),
+    dict_(storageDict.subDict("storageParameters")),
+    allocatedFieldNames_(allocatedFieldNames),
+    compressionMethod_(),
+    writeFieldTimes_(),
+    timing_(true),
+    writeAll_(false),
+    tiny_(1.e-18),
+    solDirs_((mesh_.solutionD() + Vector<label>::one)/2)
+{
+    if (Pstream::master())
+    {
+        counter++;
+    }
+    initialize();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void storageParameters::initialize()
+{
+    // Build list containing the IDs of the first cell centers next to wall
+    // boundaries
+    findCellsNextToWall();
+
+    adjustTimeStep_ =
+        mesh_.time().controlDict().getOrDefault<Switch>("adjustTimeStep", false);
+    storeAllBoundaries_ =
+        dict_.getOrDefault<Switch>("storeAllBoundaries", false);
+    storeUniformBoundaries_ =
+        dict_.getOrDefault<Switch>("storeUniformBoundaries", false);
+    algorithm_ = dict_.get<word>("algorithm");
+    timing_ = dict_.getOrDefault<bool>("timing", true);
+    Info<< nl << "General Parameters:" << nl
+        << tab << "algorithm              " << algorithm_ << nl
+        << tab << "timing                 " << timing_ << nl
+        << tab << "storeAllBoundaries     " << storeAllBoundaries_ << endl;
+    if (!timing_)
+    {
+        WarningInFunction
+            << "Timing should be deactivated only when a reduced performance "
+            << "is acceptable."
+            << endl;
+    }
+    if (!storeAllBoundaries_)
+    {
+        Info<< tab << "storeUniformBoundaries "
+            << storeUniformBoundaries_ << endl;
+        if (storeUniformBoundaries_)
+        {
+            WarningInFunction
+                << "'storeUniformBoundaries' has been activated." << nl
+                << "This is redundant but useful in debugging." << nl
+                << "Make sure it is intentional." << endl;
+        }
+    }
+    if (storeAllBoundaries_)
+    {
+        WarningInFunction
+            << "'storeAllBoundaries' should be activated only for debugging "
+            << "purposes, since unneccessary storage is allocated" << endl;
+    }
+    writeAll_ = dict_.getOrDefault<bool>("writeAll", false);
+    Info << tab << "writeAll               " << writeAll_ << endl;
+    if (!writeAll_)
+    {
+        writeFieldTimes_ =
+            dict_.getOrDefault<scalarList>("writeFieldTimes", scalarList());
+        if (writeFieldTimes_.size() > 0)
+        {
+            Info<< tab << "Time-steps to write primal fields:" << endl
+                << tab << writeFieldTimes_ << nl << endl;
+        }
+    }
+    Info << endl;
+}
+
+
+void storageParameters::reset()
+{
+    // Does nothing in base
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// ************************************************************************* //

src/optimisation/adjointOptimisation/adjoint/storage/primalStorage/storageParameters/storageParameters/storageParameters.H

@@ -0,0 +1,273 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2022 PCOpt/NTUA
+    Copyright (C) 2022      FOSS GP
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    storageParameters
+
+Description
+    Reads from dictionary and stores all parameters related to the storage
+    of the primal fields
+
+SourceFiles
+    storageParameters.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef storageParameters_H
+#define storageParameters_H
+
+#include "fvMesh.H"
+#include "dictionary.H"
+#include "runTimeSelectionTables.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                        Class storageParameters Declaration
+\*---------------------------------------------------------------------------*/
+
+class storageParameters
+{
+    static label counter;
+
+protected:
+
+
+    // Protected Data
+
+        const fvMesh& mesh_;
+
+        const dictionary dict_;
+
+        const wordList& allocatedFieldNames_;
+
+
+        // Entries read from dictionary
+
+            //- Entry defining if the simulation has a constant time-step or
+            //- not. Added here to define whether the time-step must be updated
+            //- when retrieving the variablesSet in checkPointing
+            Switch adjustTimeStep_;
+
+            //- Entry defining if all boundaries will be stored, regardless if
+            //- they contain values that can be reproduced upon reconstruction.
+            //  Defaults to false.
+            Switch storeAllBoundaries_;
+
+            //- Switch defining if the uniform boundaries must be compressed or
+            //- not. If false, a single value (scalar or vector) will be kept
+            //- for each of these boundaries. If true, these boundaries will be
+            //- stored using the same algorithm with the internalField. If
+            //- 'storeAllBoundaries' is set to true, this switch should have no
+            //- effect
+            Switch storeUniformBoundaries_;
+
+            //- Algorithm to be used for the compression (ZFP, iPGD, etc)
+            word algorithm_;
+
+            //- Entry defining the algorithm variant to be used for the
+            //- compression of each field.  Valid entries are the derived
+            //- classes of the compressedGeometricField class.  The method is
+            //- defined here once for all the objects to be created during the
+            //- optimization (of course the method may differ for each primal
+            //- field).
+            wordList compressionMethod_;
+
+            //- scalarList containing the times on which the primal fields must
+            //- be written. Both before compression and after decompression.
+            scalarList writeFieldTimes_;
+
+            //- boolean controling if all unnecessary actions are avoided to
+            //- benchmark the code
+            bool timing_;
+
+            //- boolean activated only if timing_ is set to false. If
+            //- activated, the writeFieldTimes is ignored and the 'exact' and
+            //- the reconstructed fields are written at all time-steps
+            bool writeAll_;
+
+
+        //- Small scalar value to be added in the denominator to avoid division
+        //- by zero
+        scalar tiny_;
+
+        //- Return the vector of solved-for directions in mesh.
+        //  1 indicates valid direction and 0 an invalid direction.
+        const Vector<label> solDirs_;
+
+        //- List containing the IDs of the first cell centers next to wall
+        //- boundaries
+        labelList wallList_;
+
+
+    // Protected Member Functions
+
+        //- Fills in wallList_
+        void findCellsNextToWall();
+
+
+private:
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        storageParameters(const storageParameters&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const storageParameters&) = delete;
+
+
+public:
+
+    TypeName("storageParameters");
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            storageParameters,
+            dictionary,
+            (
+                const fvMesh& mesh,
+                const dictionary& storageDict,
+                const wordList& allocatedFieldNames
+            ),
+            (mesh, storageDict, allocatedFieldNames)
+        );
+
+
+    // Constructors
+
+        //- Construct from components
+        storageParameters
+        (
+            const fvMesh& mesh,
+            const dictionary& storageDict,
+            const wordList& allocatedFieldNames
+        );
+
+
+    // Selectors
+
+        //- Return a reference to the selected storageParameters
+        static autoPtr<storageParameters> New
+        (
+            const fvMesh& mesh,
+            const dictionary& storageDict,
+            const wordList& allocatedFieldNames
+        );
+
+
+    //- Destructor
+    virtual ~storageParameters() = default;
+
+
+    // Member functions
+
+        virtual void initialize();
+
+        virtual void reset();
+
+        inline const fvMesh& mesh() const
+        {
+            return mesh_;
+        }
+
+        inline const Switch& adjustTimeStep() const
+        {
+            return adjustTimeStep_;
+        }
+
+        inline const Switch& storeAllBoundaries() const
+        {
+            return storeAllBoundaries_;
+        }
+
+        inline const Switch& storeUniformBoundaries() const
+        {
+            return storeUniformBoundaries_;
+        }
+
+        inline const word& algorithm() const
+        {
+            return algorithm_;
+        }
+
+        inline const dictionary& dict() const
+        {
+            return dict_;
+        }
+
+        inline const scalarList& writeFieldTimes() const
+        {
+            return writeFieldTimes_;
+        }
+
+        inline bool timing() const
+        {
+            return timing_;
+        }
+
+        inline bool writeAll() const
+        {
+            return writeAll_;
+        }
+
+        inline const Vector<label>& solDirs() const
+        {
+            return solDirs_;
+        }
+
+        inline const wordList& compressionMethod() const
+        {
+            return compressionMethod_;
+        }
+
+        inline scalar tiny() const
+        {
+            return tiny_;
+        }
+
+        inline const labelList& wallList() const
+        {
+            return wallList_;
+        }
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //