Merge branch 'master' of github.com-OpenFOAM:OpenFOAM/OpenFOAM-dev

applications/solvers/heatTransfer/chtMultiRegionFoam/chtMultiRegionSimpleFoam/checkResidualControls.H

@@ -53,12 +53,12 @@ if (resControlUsed)
     }
 }
 
-if (!runTime.run())
+if (!runTime.running())
 {
     Info<< "\nRegions not converged after " << runTime.timeName()
         << " iterations" << endl;
 }
-else if (runTime.run() && resControlUsed && allRegionsConverged)
+else if (runTime.running() && resControlUsed && allRegionsConverged)
 {
     Info<< "\nRegions converged after " << runTime.timeName()
         << " iterations" << endl;

applications/utilities/preProcessing/setWaves/setWaves.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2017 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2017-2018 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -72,6 +72,7 @@ int main(int argc, char *argv[])
     forAll(timeDirs, timeI)
     {
         runTime.setTime(timeDirs[timeI], timeI);
+        const scalar t = runTime.value();
 
         Info<< "Time = " << runTime.timeName() << nl << endl;
 
@@ -188,17 +189,16 @@ int main(int argc, char *argv[])
             }
             liquid = liquidp;
 
-            const scalar t = runTime.value();
             const pointField& ccs = mesh.cellCentres();
             const pointField& pts = mesh.points();
 
             // Internal field superposition
             h.primitiveFieldRef() += waves.height(t, ccs);
             hp.primitiveFieldRef() += waves.height(t, pts);
-            uGas.primitiveFieldRef() += waves.UGas(t, ccs) - waves.UMean();
+            uGas.primitiveFieldRef() += waves.UGas(t, ccs) - waves.UMean(t);
-            uGasp.primitiveFieldRef() += waves.UGas(t, pts) - waves.UMean();
+            uGasp.primitiveFieldRef() += waves.UGas(t, pts) - waves.UMean(t);
-            uLiq.primitiveFieldRef() += waves.ULiquid(t, ccs) - waves.UMean();
+            uLiq.primitiveFieldRef() += waves.ULiquid(t, ccs) - waves.UMean(t);
-            uLiqp.primitiveFieldRef() += waves.ULiquid(t, pts) - waves.UMean();
+            uLiqp.primitiveFieldRef() += waves.ULiquid(t, pts) - waves.UMean(t);
 
             // Boundary field superposition
             forAll(mesh.boundary(), patchj)
@@ -206,9 +206,9 @@ int main(int argc, char *argv[])
                 const pointField& fcs = mesh.boundary()[patchj].Cf();
                 h.boundaryFieldRef()[patchj] += waves.height(t, fcs);
                 uGas.boundaryFieldRef()[patchj] +=
-                    waves.UGas(t, fcs) - waves.UMean();
+                    waves.UGas(t, fcs) - waves.UMean(t);
                 uLiq.boundaryFieldRef()[patchj] +=
-                    waves.ULiquid(t, fcs) - waves.UMean();
+                    waves.ULiquid(t, fcs) - waves.UMean(t);
             }
 
             ++ nWaves;
@@ -246,7 +246,8 @@ int main(int argc, char *argv[])
                 const waveSuperposition& waves =
                     refCast<const waveVelocityFvPatchVectorField>(Up).waves();
 
-                UMean == dimensionedVector("UMean", dimVelocity, waves.UMean());
+                UMean ==
+                    dimensionedVector("UMean", dimVelocity, waves.UMean(t));
             }
         }
         else if (nWaves > 1)
@@ -290,7 +291,7 @@ int main(int argc, char *argv[])
 
                 weight += w;
                 weightUMean +=
-                    w*dimensionedVector("wUMean", dimVelocity, waves.UMean());
+                    w*dimensionedVector("wUMean", dimVelocity, waves.UMean(t));
             }
 
             // Complete the average for the mean velocity

src/OpenFOAM/db/Time/Time.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -778,9 +778,15 @@ Foam::dimensionedScalar Foam::Time::endTime() const
 }
 
 
+bool Foam::Time::running() const
+{
+    return value() < (endTime_ - 0.5*deltaT_);
+}
+
+
 bool Foam::Time::run() const
 {
-    bool running = value() < (endTime_ - 0.5*deltaT_);
+    const bool running = this->running();
 
     if (!subCycling_)
     {
@@ -806,21 +812,18 @@ bool Foam::Time::run() const
                 functionObjects_.execute();
             }
         }
-
-        // Update the "running" status following the
-        // possible side-effects from functionObjects
-        running = value() < (endTime_ - 0.5*deltaT_);
     }
 
-    return running;
+    // Re-evaluate if running in case a function object has changed things
+    return this->running();
 }
 
 
 bool Foam::Time::loop()
 {
-    bool running = run();
+    const bool running = this->running();
 
-    if (running)
+    if (run())
     {
         operator++();
     }

src/OpenFOAM/db/Time/Time.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -443,6 +443,9 @@ public:
 
         // Check
 
+            //- Return true if run should continue without any side effects
+            virtual bool running() const;
+
             //- Return true if run should continue,
             //  also invokes the functionObjectList::end() method
             //  when the time goes out of range

src/finiteVolume/fields/fvPatchFields/derived/outletPhaseMeanVelocity/outletPhaseMeanVelocityFvPatchVectorField.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2013-2016 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2013-2018 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -40,6 +40,7 @@ Foam::outletPhaseMeanVelocityFvPatchVectorField
 :
     mixedFvPatchField<vector>(p, iF),
     Umean_(0),
+    ramp_(),
     alphaName_("none")
 {
     refValue() = Zero;
@@ -59,6 +60,7 @@ Foam::outletPhaseMeanVelocityFvPatchVectorField
 :
     mixedFvPatchField<vector>(ptf, p, iF, mapper),
     Umean_(ptf.Umean_),
+    ramp_(ptf.ramp_, false),
     alphaName_(ptf.alphaName_)
 {}
 
@@ -73,6 +75,12 @@ Foam::outletPhaseMeanVelocityFvPatchVectorField
 :
     mixedFvPatchField<vector>(p, iF),
     Umean_(readScalar(dict.lookup("Umean"))),
+    ramp_
+    (
+        dict.found("ramp")
+      ? Function1<scalar>::New("ramp", dict)
+      : autoPtr<Function1<scalar>>()
+    ),
     alphaName_(dict.lookup("alpha"))
 {
     refValue() = Zero;
@@ -101,6 +109,7 @@ Foam::outletPhaseMeanVelocityFvPatchVectorField
 :
     mixedFvPatchField<vector>(ptf),
     Umean_(ptf.Umean_),
+    ramp_(ptf.ramp_, false),
     alphaName_(ptf.alphaName_)
 {}
 
@@ -114,6 +123,7 @@ Foam::outletPhaseMeanVelocityFvPatchVectorField
 :
     mixedFvPatchField<vector>(ptf, iF),
     Umean_(ptf.Umean_),
+    ramp_(ptf.ramp_, false),
     alphaName_(ptf.alphaName_)
 {}
 
@@ -127,6 +137,8 @@ void Foam::outletPhaseMeanVelocityFvPatchVectorField::updateCoeffs()
         return;
     }
 
+    const scalar t = this->db().time().timeOutputValue();
+
     scalarField alphap =
         patch().lookupPatchField<volScalarField, scalar>(alphaName_);
 
@@ -143,15 +155,16 @@ void Foam::outletPhaseMeanVelocityFvPatchVectorField::updateCoeffs()
 
     // Set the refValue and valueFraction to adjust the boundary field
     // such that the phase mean is Umean_
-    if (Uzgmean >= Umean_)
+    const scalar Umean = (ramp_.valid() ? ramp_->value(t) : 1)*Umean_;
+    if (Uzgmean >= Umean)
     {
         refValue() = Zero;
-        valueFraction() = 1.0 - Umean_/Uzgmean;
+        valueFraction() = 1.0 - Umean/Uzgmean;
     }
     else
     {
-        refValue() = (Umean_ + Uzgmean)*patch().nf();
+        refValue() = (Umean + Uzgmean)*patch().nf();
-        valueFraction() = 1.0 - Uzgmean/Umean_;
+        valueFraction() = 1.0 - Uzgmean/Umean;
     }
 
     mixedFvPatchField<vector>::updateCoeffs();
@@ -165,10 +178,12 @@ void Foam::outletPhaseMeanVelocityFvPatchVectorField::write
 {
     fvPatchField<vector>::write(os);
 
-    os.writeKeyword("Umean") << Umean_
+    os.writeKeyword("Umean") << Umean_ << token::END_STATEMENT << nl;
-        << token::END_STATEMENT << nl;
+    if (ramp_.valid())
-    os.writeKeyword("alpha") << alphaName_
+    {
-        << token::END_STATEMENT << nl;
+        ramp_->writeData(os);
+    }
+    os.writeKeyword("alpha") << alphaName_ << token::END_STATEMENT << nl;
     writeEntry("value", os);
 }
 

src/finiteVolume/fields/fvPatchFields/derived/outletPhaseMeanVelocity/outletPhaseMeanVelocityFvPatchVectorField.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2013-2016 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2013-2018 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -39,6 +39,7 @@ Usage
     \table
         Property     | Description             | Required    | Default value
         Umean        | mean velocity normal to the boundary [m/s] | yes |
+        ramp         | ramping function for the mean flow speed | no | None
         alpha        | phase-fraction field    | yes |
     \endtable
 
@@ -66,6 +67,7 @@ SourceFiles
 #define outletPhaseMeanVelocityFvPatchVectorField_H
 
 #include "mixedFvPatchFields.H"
+#include "Function1.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -84,6 +86,9 @@ class outletPhaseMeanVelocityFvPatchVectorField
         //- Inlet integral flow rate
         scalar Umean_;
 
+        //- Ramp for the mean flow rate
+        autoPtr<Function1<scalar>> ramp_;
+
         //- Name of the phase-fraction field
         word alphaName_;
 
@@ -163,21 +168,6 @@ public:
 
     // Member functions
 
-        // Access
-
-            //- Return the flux
-            scalar Umean() const
-            {
-                return Umean_;
-            }
-
-            //- Return reference to the flux to allow adjustment
-            scalar& Umean()
-            {
-                return Umean_;
-            }
-
-
         //- Update the coefficients associated with the patch field
         virtual void updateCoeffs();
 

src/fvOptions/Make/files

@@ -39,6 +39,7 @@ $(derivedSources)/buoyancyEnergy/buoyancyEnergy.C
 $(derivedSources)/buoyancyEnergy/buoyancyEnergyIO.C
 $(derivedSources)/verticalDamping/verticalDamping.C
 $(derivedSources)/phaseLimitStabilization/phaseLimitStabilization.C
+$(derivedSources)/velocityRamping/velocityRamping.C
 
 interRegion = sources/interRegion
 $(interRegion)/interRegionHeatTransfer/interRegionHeatTransferModel/interRegionHeatTransferModel.C

src/fvOptions/sources/derived/velocityRamping/velocityRamping.C

@@ -0,0 +1,118 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2018 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+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 "fvMesh.H"
+#include "fvMatrix.H"
+#include "geometricOneField.H"
+#include "velocityRamping.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fv
+{
+    defineTypeNameAndDebug(velocityRamping, 0);
+    addToRunTimeSelectionTable(option, velocityRamping, dictionary);
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::fv::velocityRamping::velocityRamping
+(
+    const word& name,
+    const word& modelType,
+    const dictionary& dict,
+    const fvMesh& mesh
+)
+:
+    cellSetOption(name, modelType, dict, mesh),
+    velocity_(vector::zero),
+    ramp_(nullptr)
+{
+    read(dict);
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::fv::velocityRamping::addSup
+(
+    fvMatrix<vector>& eqn,
+    const label fieldi
+)
+{
+    add(geometricOneField(), eqn, fieldi);
+}
+
+
+void Foam::fv::velocityRamping::addSup
+(
+    const volScalarField& rho,
+    fvMatrix<vector>& eqn,
+    const label fieldi
+)
+{
+    add(rho, eqn, fieldi);
+}
+
+
+void Foam::fv::velocityRamping::addSup
+(
+    const volScalarField& alpha,
+    const volScalarField& rho,
+    fvMatrix<vector>& eqn,
+    const label fieldi
+)
+{
+    add((alpha*rho)(), eqn, fieldi);
+}
+
+
+bool Foam::fv::velocityRamping::read(const dictionary& dict)
+{
+    if (cellSetOption::read(dict))
+    {
+        fieldNames_ = wordList(1, coeffs_.lookupOrDefault<word>("U", "U"));
+
+        applied_.setSize(1, false);
+
+        velocity_ = dict.lookupType<vector>("velocity");
+
+        ramp_ = Function1<scalar>::New("ramp", dict);
+
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
+// ************************************************************************* //

src/fvOptions/sources/derived/velocityRamping/velocityRamping.H

@@ -0,0 +1,173 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2018 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+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::fv::velocityRamping
+
+Description
+    This fvOption applies an explicit acceleration force to components of the
+    velocity field.
+
+Usage
+    Example usage:
+    \verbatim
+    velocityRamping
+    {
+        type        velocityRamping;
+        active      on;
+        selectionMode all;
+        U           U;
+        velocity    (-2.572 0 0);
+        ramp
+        {
+            type        quarterSineRamp;
+            start       0;
+            duration    10;
+        }
+    }
+    \endverbatim
+
+SourceFiles
+    velocityRamping.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef velocityRamping_H
+#define velocityRamping_H
+
+#include "cellSetOption.H"
+#include "Function1.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fv
+{
+
+/*---------------------------------------------------------------------------*\
+                       Class velocityRamping Declaration
+\*---------------------------------------------------------------------------*/
+
+class velocityRamping
+:
+    public cellSetOption
+{
+private:
+
+    // Private data
+
+        //- Velocity at the end of the ramp
+        vector velocity_;
+
+        //- Ramp function
+        autoPtr<Function1<scalar>> ramp_;
+
+
+    // Private Member Functions
+
+        //- Source term to momentum equation
+        template<class AlphaRhoFieldType>
+        void add
+        (
+            const AlphaRhoFieldType& rho,
+            fvMatrix<vector>& eqn,
+            const label fieldi
+        );
+
+
+public:
+
+    //- Runtime type information
+    TypeName("velocityRamping");
+
+
+    // Constructors
+
+        //- Construct from components
+        velocityRamping
+        (
+            const word& name,
+            const word& modelType,
+            const dictionary& dict,
+            const fvMesh& mesh
+        );
+
+
+    //- Destructor
+    virtual ~velocityRamping()
+    {}
+
+
+    // Member Functions
+
+         // Add explicit and implicit contributions
+
+            //- Source term to momentum equation
+            virtual void addSup
+            (
+                fvMatrix<vector>& eqn,
+                const label fieldi
+            );
+
+            //- Source term to compressible momentum equation
+            virtual void addSup
+            (
+                const volScalarField& rho,
+                fvMatrix<vector>& eqn,
+                const label fieldi
+            );
+
+            //- Source term to phase momentum equation
+            virtual void addSup
+            (
+                const volScalarField& alpha,
+                const volScalarField& rho,
+                fvMatrix<vector>& eqn,
+                const label fieldi
+            );
+
+
+        // IO
+
+            //- Read dictionary
+            virtual bool read(const dictionary& dict);
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace fv
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "velocityRampingTemplates.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/fvOptions/sources/derived/velocityRamping/velocityRampingTemplates.C

@@ -0,0 +1,51 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2018 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+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/>.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+template<class AlphaRhoFieldType>
+void Foam::fv::velocityRamping::add
+(
+    const AlphaRhoFieldType& alphaRho,
+    fvMatrix<vector>& eqn,
+    const label fieldi
+)
+{
+    const DimensionedField<scalar, volMesh>& V = mesh_.V();
+
+    const scalar t = mesh_.time().value();
+    const scalar dt = mesh_.time().deltaTValue();
+    const vector dU = velocity_*(ramp_->value(t) - ramp_->value(t - dt));
+    const vector a = dU/mesh_.time().deltaTValue();
+
+    forAll(cells_, i)
+    {
+        const label c = cells_[i];
+        eqn.source()[c] -= V[c]*alphaRho[c]*a;
+    }
+}
+
+
+// ************************************************************************* //

src/waves/derivedFvPatchFields/waveVelocity/waveVelocityFvPatchVectorField.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2017 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2017-2018 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -60,6 +60,7 @@ Usage
         direction   | direction of the mean flow             | yes    |
         speed       | speed of the mean flow                 | yes    |
         waves       | list of wave models to superimpose     | yes    |
+        ramp        | ramping function for the mean flow speed | no   | None
         scale       | scale factor along the mean flow direction | no | None
         crossScale  | scale factor across the mean flow direction | no | None
         phi         | Name of the flux field                 | no     | phi
@@ -91,6 +92,7 @@ Usage
                 angle       0;
             }
         );
+        ramp        constant 1;
         scale       table ((100 1) (200 0));
         crossScale  constant 1;
     }

src/waves/waveSuperposition/waveSuperposition.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2017 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2017-2018 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -180,6 +180,7 @@ Foam::waveSuperposition::waveSuperposition(const objectRegistry& db)
     speed_(0),
     waveModels_(),
     waveAngles_(),
+    ramp_(),
     scale_(),
     crossScale_()
 {}
@@ -193,6 +194,7 @@ Foam::waveSuperposition::waveSuperposition(const waveSuperposition& waves)
     speed_(waves.speed_),
     waveModels_(waves.waveModels_),
     waveAngles_(waves.waveAngles_),
+    ramp_(waves.ramp_, false),
     scale_(waves.scale_, false),
     crossScale_(waves.crossScale_, false)
 {}
@@ -210,6 +212,12 @@ Foam::waveSuperposition::waveSuperposition
     speed_(readScalar(dict.lookup("speed"))),
     waveModels_(),
     waveAngles_(),
+    ramp_
+    (
+        dict.found("ramp")
+      ? Function1<scalar>::New("ramp", dict)
+      : autoPtr<Function1<scalar>>()
+    ),
     scale_
     (
         dict.found("scale")
@@ -277,7 +285,7 @@ Foam::tmp<Foam::vectorField> Foam::waveSuperposition::ULiquid
     vectorField xyz(p.size());
     transformation(p, axes, u, xyz);
 
-    return UMean() + (velocity(t, xyz) & axes);
+    return UMean(t) + (velocity(t, xyz) & axes);
 }
 
 
@@ -294,7 +302,7 @@ Foam::tmp<Foam::vectorField> Foam::waveSuperposition::UGas
 
     axes = tensor(- axes.x(), - axes.y(), axes.z());
 
-    return UMean() + (velocity(t, xyz) & axes);
+    return UMean(t) + (velocity(t, xyz) & axes);
 }
 
 
@@ -338,6 +346,10 @@ void Foam::waveSuperposition::write(Ostream& os) const
             << nl << decrIndent << indent << token::END_BLOCK << nl;
     }
     os  << decrIndent << token::END_LIST << token::END_STATEMENT << nl;
+    if (ramp_.valid())
+    {
+        ramp_->writeData(os);
+    }
     if (scale_.valid())
     {
         scale_->writeData(os);

src/waves/waveSuperposition/waveSuperposition.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2017 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2017-2018 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -69,6 +69,9 @@ class waveSuperposition
         //- The angle relative to the mean velocity at which the waves propagate
         scalarList waveAngles_;
 
+        //- Ramp for the mean flow speed
+        const autoPtr<Function1<scalar>> ramp_;
+
         //- Scaling in the flow direction
         const autoPtr<Function1<scalar>> scale_;
 
@@ -147,9 +150,9 @@ public:
         tmp<scalarField> pGas(const scalar t, const vectorField& p) const;
 
         //- Get the mean flow velocity
-        inline vector UMean() const
+        inline vector UMean(const scalar t) const
         {
-            return direction_*speed_;
+            return (ramp_.valid() ? ramp_->value(t) : 1)*direction_*speed_;
         }
 
         //- Write