compressibleVoF,compressibleMultiphaseVoF: Apply fvConstraints to the pressure

Replaces the hard-coded pMin.

applications/solvers/modules/compressibleMultiphaseVoF/compressibleMultiphaseVoF.C

@@ -77,13 +77,6 @@ Foam::solvers::compressibleMultiphaseVoF::compressibleMultiphaseVoF
         false
     ),
 
-    pMin
-    (
-        "pMin",
-        dimPressure,
-        mixture
-    ),
-
     K("K", 0.5*magSqr(U)),
 
     momentumTransport_

applications/solvers/modules/compressibleMultiphaseVoF/compressibleMultiphaseVoF.H

@@ -94,9 +94,6 @@ protected:
         //- Pressure reference
         Foam::pressureReference pressureReference_;
 
-        //- Minimum pressure
-        dimensionedScalar pMin;
-
 
     // Kinematic properties
 

applications/solvers/modules/compressibleMultiphaseVoF/pressureCorrector.C

@@ -141,7 +141,8 @@ void Foam::solvers::compressibleMultiphaseVoF::pressureCorrector()
 
                 phi = phiHbyA + p_rghEqnIncomp.flux();
 
-                p = max(p_rgh + mixture.rho()*buoyancy.gh, pMin);
+                p = p_rgh + rho*buoyancy.gh;
+                fvConstraints().constrain(p);
                 p_rgh = p - rho*buoyancy.gh;
                 p_rgh.correctBoundaryConditions();
 

applications/solvers/modules/compressibleVoF/compressibleVoF.C

@@ -79,13 +79,6 @@ Foam::solvers::compressibleVoF::compressibleVoF(fvMesh& mesh)
         false
     ),
 
-    pMin
-    (
-        "pMin",
-        dimPressure,
-        mixture_
-    ),
-
     alphaRhoPhi1
     (
         IOobject::groupName("alphaRhoPhi", alpha1.group()),

applications/solvers/modules/compressibleVoF/compressibleVoF.H

@@ -101,9 +101,6 @@ protected:
         //- Pressure reference
         Foam::pressureReference pressureReference_;
 
-        //- Minimum pressure
-        dimensionedScalar pMin;
-
 
     // Kinematic properties
 

applications/solvers/modules/compressibleVoF/pressureCorrector.C

@@ -200,8 +200,9 @@ void Foam::solvers::compressibleVoF::pressureCorrector()
 
                 phi = phiHbyA + p_rghEqnIncomp.flux();
 
-                p = max(p_rgh + (alpha1*rho1 + alpha2*rho2)*buoyancy.gh, pMin);
-                p_rgh = p - (alpha1*rho1 + alpha2*rho2)*buoyancy.gh;
+                p = p_rgh + rho*buoyancy.gh;
+                fvConstraints().constrain(p);
+                p_rgh = p - rho*buoyancy.gh;
                 p_rgh.correctBoundaryConditions();
 
                 U = HbyA

src/fvConstraints/bound/boundConstraint.C

@@ -0,0 +1,121 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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 "boundConstraint.H"
+#include "volFields.H"
+#include "bound.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fv
+{
+    defineTypeNameAndDebug(bound, 0);
+    addToRunTimeSelectionTable
+    (
+        fvConstraint,
+        bound,
+        dictionary
+    );
+}
+}
+
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+void Foam::fv::bound::readCoeffs()
+{
+    fieldName_ = coeffs().lookup<word>("field");
+    min_ = coeffs().lookup<scalar>("min");
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::fv::bound::bound
+(
+    const word& name,
+    const word& modelType,
+    const fvMesh& mesh,
+    const dictionary& dict
+)
+:
+    fvConstraint(name, modelType, mesh, dict),
+    fieldName_(word::null),
+    min_(0)
+{
+    readCoeffs();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+Foam::wordList Foam::fv::bound::constrainedFields() const
+{
+    return wordList(1, fieldName_);
+}
+
+
+bool Foam::fv::bound::constrain(volScalarField& f) const
+{
+    return Foam::bound(f, dimensionedScalar(f.dimensions(), min_));
+}
+
+
+bool Foam::fv::bound::movePoints()
+{
+    return true;
+}
+
+
+void Foam::fv::bound::topoChange(const polyTopoChangeMap&)
+{}
+
+
+void Foam::fv::bound::mapMesh(const polyMeshMap&)
+{}
+
+
+void Foam::fv::bound::distribute(const polyDistributionMap&)
+{}
+
+
+bool Foam::fv::bound::read(const dictionary& dict)
+{
+    if (fvConstraint::read(dict))
+    {
+        readCoeffs();
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
+// ************************************************************************* //

src/fvConstraints/bound/boundConstraint.H

@@ -0,0 +1,153 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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::bound
+
+Description
+    Bound the specified scalar field where it is below the specified minimum.
+
+    Where the field is unbounded it is set to the maximum of the average of
+    the neighbouring cell values and the specified minimum.
+
+Usage
+    Example usage:
+    \verbatim
+    limitp
+    {
+        type            bound;
+
+        field           p;
+
+        min             100;
+    }
+    \endverbatim
+
+SourceFiles
+    bound.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef boundConstraint_H
+#define boundConstraint_H
+
+#include "fvConstraint.H"
+#include "dimensionedScalar.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fv
+{
+
+/*---------------------------------------------------------------------------*\
+                      Class bound Declaration
+\*---------------------------------------------------------------------------*/
+
+class bound
+:
+    public fvConstraint
+{
+    // Private data
+
+        //- Field name
+        word fieldName_;
+
+        //- Minimum value
+        scalar min_;
+
+
+    // Private Member Functions
+
+        //- Non-virtual read
+        void readCoeffs();
+
+
+public:
+
+    //- Runtime type information
+    TypeName("bound");
+
+
+    // Constructors
+
+        //- Construct from components
+        bound
+        (
+            const word& name,
+            const word& modelType,
+            const fvMesh& mesh,
+            const dictionary& dict
+        );
+
+        //- Disallow default bitwise copy construction
+        bound(const bound&) = delete;
+
+
+    //- Destructor
+    virtual ~bound()
+    {}
+
+
+    // Member Functions
+
+        //- Return the list of fields constrained by the fvConstraint
+        virtual wordList constrainedFields() const;
+
+        //- Constrain the pressure field
+        virtual bool constrain(volScalarField& p) const;
+
+        //- Update for mesh motion
+        virtual bool movePoints();
+
+        //- Update topology using the given map
+        virtual void topoChange(const polyTopoChangeMap&);
+
+        //- Update from another mesh using the given map
+        virtual void mapMesh(const polyMeshMap&);
+
+        //- Redistribute or update using the given distribution map
+        virtual void distribute(const polyDistributionMap&);
+
+        //- Read dictionary
+        virtual bool read(const dictionary& dict);
+
+
+    // Member Operators
+
+        //- Disallow default bitwise assignment
+        void operator=(const bound&) = delete;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace fv
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/fvConstraints/fixedTemperature/fixedTemperatureConstraint.C

@@ -0,0 +1,241 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2012-2023 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 "fixedTemperatureConstraint.H"
+#include "fvMesh.H"
+#include "fvMatrices.H"
+#include "basicThermo.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    namespace fv
+    {
+        defineTypeNameAndDebug(fixedTemperatureConstraint, 0);
+        addToRunTimeSelectionTable
+        (
+            fvConstraint,
+            fixedTemperatureConstraint,
+            dictionary
+        );
+    }
+
+    template<>
+    const char* NamedEnum<fv::fixedTemperatureConstraint::temperatureMode, 2>::
+    names[] =
+    {
+        "uniform",
+        "lookup"
+    };
+}
+
+const Foam::NamedEnum<Foam::fv::fixedTemperatureConstraint::temperatureMode, 2>
+    Foam::fv::fixedTemperatureConstraint::modeNames_;
+
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+void Foam::fv::fixedTemperatureConstraint::readCoeffs()
+{
+    mode_ = modeNames_.read(coeffs().lookup("mode"));
+
+    switch (mode_)
+    {
+        case temperatureMode::uniform:
+        {
+            TValue_.reset
+            (
+                Function1<scalar>::New("temperature", coeffs()).ptr()
+            );
+            break;
+        }
+        case temperatureMode::lookup:
+        {
+            TName_ = coeffs().lookupOrDefault<word>("T", "T");
+            break;
+        }
+    }
+
+    phaseName_ = coeffs().lookupOrDefault<word>("phase", word::null);
+
+    fraction_ =
+        coeffs().found("fraction")
+      ? Function1<scalar>::New("fraction", coeffs())
+      : autoPtr<Function1<scalar>>();
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::fv::fixedTemperatureConstraint::fixedTemperatureConstraint
+(
+    const word& name,
+    const word& modelType,
+    const fvMesh& mesh,
+    const dictionary& dict
+)
+:
+    fvConstraint(name, modelType, mesh, dict),
+    set_(mesh, coeffs()),
+    mode_(temperatureMode::uniform),
+    TValue_(nullptr),
+    TName_(word::null),
+    phaseName_(word::null)
+{
+    readCoeffs();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+Foam::wordList Foam::fv::fixedTemperatureConstraint::constrainedFields() const
+{
+    const basicThermo& thermo =
+        mesh().lookupObject<basicThermo>
+        (
+            IOobject::groupName(physicalProperties::typeName, phaseName_)
+        );
+
+    return wordList(1, thermo.he().name());
+}
+
+
+bool Foam::fv::fixedTemperatureConstraint::constrain
+(
+    fvMatrix<scalar>& eqn,
+    const word& fieldName
+) const
+{
+    const labelUList cells = set_.cells();
+
+    const basicThermo& thermo =
+        mesh().lookupObject<basicThermo>
+        (
+            IOobject::groupName(physicalProperties::typeName, phaseName_)
+        );
+
+    const scalar t = mesh().time().userTimeValue();
+
+    switch (mode_)
+    {
+        case temperatureMode::uniform:
+        {
+            const scalarField Tuni(cells.size(), TValue_->value(t));
+            const scalarField heuni(thermo.he(Tuni, cells));
+
+            if (fraction_.valid())
+            {
+                eqn.setValues
+                (
+                    cells,
+                    heuni,
+                    scalarList(cells.size(), fraction_->value(t))
+                );
+            }
+            else
+            {
+                eqn.setValues(cells, heuni);
+            }
+
+            break;
+        }
+        case temperatureMode::lookup:
+        {
+            const volScalarField& T =
+                mesh().lookupObject<volScalarField>(TName_);
+            const scalarField Tlkp(T, cells);
+            const scalarField helkp(thermo.he(Tlkp, cells));
+
+            if (fraction_.valid())
+            {
+                eqn.setValues
+                (
+                    cells,
+                    helkp,
+                    scalarList(cells.size(), fraction_->value(t))
+                );
+            }
+            else
+            {
+                eqn.setValues(cells, helkp);
+            }
+
+            break;
+        }
+    }
+
+    return cells.size();
+}
+
+
+bool Foam::fv::fixedTemperatureConstraint::movePoints()
+{
+    set_.movePoints();
+    return true;
+}
+
+
+void Foam::fv::fixedTemperatureConstraint::topoChange
+(
+    const polyTopoChangeMap& map
+)
+{
+    set_.topoChange(map);
+}
+
+
+void Foam::fv::fixedTemperatureConstraint::mapMesh(const polyMeshMap& map)
+{
+    set_.mapMesh(map);
+}
+
+
+void Foam::fv::fixedTemperatureConstraint::distribute
+(
+    const polyDistributionMap& map
+)
+{
+    set_.distribute(map);
+}
+
+
+bool Foam::fv::fixedTemperatureConstraint::read(const dictionary& dict)
+{
+    if (fvConstraint::read(dict))
+    {
+        set_.read(coeffs());
+        readCoeffs();
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
+// ************************************************************************* //

src/fvConstraints/fixedTemperature/fixedTemperatureConstraint.H

@@ -0,0 +1,195 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2012-2023 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::fixedTemperatureConstraint
+
+Description
+    Fixed temperature equation constraint
+
+Usage
+    \verbatim
+    fixedTemperature
+    {
+        type            fixedTemperatureConstraint;
+
+        select          all;
+
+        phase           gas; // Optional phase name
+
+        // Uniform temperature constraint
+        mode            uniform;
+        temperature     constant 500; // Uniform temperature
+
+        // // Looked-up field temperature constraint
+        // T            T; // Temperature field name
+    }
+    \endverbatim
+
+    Note:
+        The 'uniform' option allows the use of a time-varying uniform
+        temperature by means of the Function1 type.
+
+SourceFiles
+    fixedTemperatureConstraint.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef fixedTemperatureConstraint_H
+#define fixedTemperatureConstraint_H
+
+#include "fvConstraint.H"
+#include "fvCellSet.H"
+#include "NamedEnum.H"
+#include "Function1.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fv
+{
+
+/*---------------------------------------------------------------------------*\
+                 Class fixedTemperatureConstraint Declaration
+\*---------------------------------------------------------------------------*/
+
+class fixedTemperatureConstraint
+:
+    public fvConstraint
+{
+public:
+
+    //- Temperature mode
+    enum class temperatureMode
+    {
+        uniform,
+        lookup
+    };
+
+    //- String representation of mode enums
+    static const NamedEnum<temperatureMode, 2> modeNames_;
+
+
+private:
+
+    // Private Data
+
+        //- The set of cells the fvConstraint applies to
+        fvCellSet set_;
+
+        //- Operation mode
+        temperatureMode mode_;
+
+        //- Uniform temperature [K]
+        autoPtr<Function1<scalar>> TValue_;
+
+        //- Temperature field name
+        word TName_;
+
+        //- Optional phase name
+        word phaseName_;
+
+        //- Fraction of the constraint to apply. Facilitates ramping, or
+        //  pulsing, or deactivation after a time. Should take a value between
+        //  0 and 1. Defaults to 1 (i.e., apply all of the constraint).
+        autoPtr<Function1<scalar>> fraction_;
+
+
+    // Private Member Functions
+
+        //- Non-virtual read
+        void readCoeffs();
+
+
+public:
+
+    //- Runtime type information
+    TypeName("fixedTemperatureConstraint");
+
+
+    // Constructors
+
+        //- Construct from components
+        fixedTemperatureConstraint
+        (
+            const word& name,
+            const word& modelType,
+            const fvMesh& mesh,
+            const dictionary& dict
+        );
+
+        //- Disallow default bitwise copy construction
+        fixedTemperatureConstraint(const fixedTemperatureConstraint&) = delete;
+
+
+    //- Destructor
+    virtual ~fixedTemperatureConstraint()
+    {}
+
+
+    // Member Functions
+
+        //- Return the list of fields constrained by the fvConstraint
+        virtual wordList constrainedFields() const;
+
+        //- Constrain energy equation to fix the temperature
+        virtual bool constrain
+        (
+            fvMatrix<scalar>& eqn,
+            const word& fieldName
+        ) const;
+
+        //- Update for mesh motion
+        virtual bool movePoints();
+
+        //- Update topology using the given map
+        virtual void topoChange(const polyTopoChangeMap&);
+
+        //- Update from another mesh using the given map
+        virtual void mapMesh(const polyMeshMap&);
+
+        //- Redistribute or update using the given distribution map
+        virtual void distribute(const polyDistributionMap&);
+
+        //- Read dictionary
+        virtual bool read(const dictionary& dict);
+
+
+    // Member Operators
+
+        //- Disallow default bitwise assignment
+        void operator=(const fixedTemperatureConstraint&) = delete;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace fv
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/fvConstraints/fixedValue/fixedValueConstraint.C

@@ -0,0 +1,183 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2016-2023 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 "fixedValueConstraint.H"
+#include "fvMesh.H"
+#include "fvMatrices.H"
+#include "fvcSurfaceIntegrate.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fv
+{
+    defineTypeNameAndDebug(fixedValueConstraint, 0);
+
+    addToRunTimeSelectionTable
+    (
+        fvConstraint,
+        fixedValueConstraint,
+        dictionary
+    );
+}
+}
+
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+void Foam::fv::fixedValueConstraint::readCoeffs()
+{
+    fieldValues_.clear();
+    forAllConstIter(dictionary, coeffs().subDict("fieldValues"), iter)
+    {
+        fieldValues_.set
+        (
+            iter().keyword(),
+            new unknownTypeFunction1
+            (
+                iter().keyword(),
+                coeffs().subDict("fieldValues")
+            )
+        );
+    }
+
+    fraction_ =
+        coeffs().found("fraction")
+      ? Function1<scalar>::New("fraction", coeffs())
+      : autoPtr<Function1<scalar>>();
+}
+
+
+template<class Type>
+bool Foam::fv::fixedValueConstraint::constrainType
+(
+    fvMatrix<Type>& eqn,
+    const word& fieldName
+) const
+{
+    const scalar t = mesh().time().userTimeValue();
+
+    const List<Type> values
+    (
+        set_.nCells(),
+        fieldValues_[fieldName]->value<Type>(t)
+    );
+
+    if (fraction_.valid())
+    {
+        eqn.setValues
+        (
+            set_.cells(),
+            values,
+            scalarList(set_.nCells(), fraction_->value(t))
+        );
+    }
+    else
+    {
+        eqn.setValues(set_.cells(), values);
+    }
+
+    return set_.nCells();
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::fv::fixedValueConstraint::fixedValueConstraint
+(
+    const word& name,
+    const word& modelType,
+    const fvMesh& mesh,
+    const dictionary& dict
+)
+:
+    fvConstraint(name, modelType, mesh, dict),
+    set_(mesh, coeffs())
+{
+    readCoeffs();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+Foam::wordList Foam::fv::fixedValueConstraint::constrainedFields() const
+{
+    return fieldValues_.toc();
+}
+
+
+FOR_ALL_FIELD_TYPES
+(
+    IMPLEMENT_FV_CONSTRAINT_CONSTRAIN,
+    fv::fixedValueConstraint
+);
+
+
+bool Foam::fv::fixedValueConstraint::movePoints()
+{
+    set_.movePoints();
+    return true;
+}
+
+
+void Foam::fv::fixedValueConstraint::topoChange(const polyTopoChangeMap& map)
+{
+    set_.topoChange(map);
+}
+
+
+void Foam::fv::fixedValueConstraint::mapMesh(const polyMeshMap& map)
+{
+    set_.mapMesh(map);
+}
+
+
+void Foam::fv::fixedValueConstraint::distribute
+(
+    const polyDistributionMap& map
+)
+{
+    set_.distribute(map);
+}
+
+
+bool Foam::fv::fixedValueConstraint::read(const dictionary& dict)
+{
+    if (fvConstraint::read(dict))
+    {
+        set_.read(coeffs());
+        readCoeffs();
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
+// ************************************************************************* //

src/fvConstraints/fixedValue/fixedValueConstraint.H

@@ -0,0 +1,156 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2016-2023 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::fixedValueConstraint
+
+Description
+    Constrain the field values within a specified region.
+
+Usage
+    For example to set the turbulence properties within a porous region:
+    \verbatim
+    porosityTurbulence
+    {
+        type            fixedValueConstraint;
+
+        select          cellZone;
+        cellZone        porosity;
+
+        fieldValues
+        {
+            k           1;
+            epsilon     150;
+        }
+    }
+    \endverbatim
+
+SourceFiles
+    fixedValueConstraint.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef fixedValueConstraint_H
+#define fixedValueConstraint_H
+
+#include "fvConstraint.H"
+#include "fvCellSet.H"
+#include "unknownTypeFunction1.H"
+#include "HashPtrTable.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fv
+{
+
+/*---------------------------------------------------------------------------*\
+                    Class fixedValueConstraint Declaration
+\*---------------------------------------------------------------------------*/
+
+class fixedValueConstraint
+:
+    public fvConstraint
+{
+    // Private Member Data
+
+        //- The set of cells the fvConstraint applies to
+        fvCellSet set_;
+
+        //- Field values
+        HashPtrTable<unknownTypeFunction1> fieldValues_;
+
+        //- Fraction of the constraint to apply. Facilitates ramping, or
+        //  pulsing, or deactivation after a time. Should take a value between
+        //  0 and 1. Defaults to 1 (i.e., apply all of the constraint).
+        autoPtr<Function1<scalar>> fraction_;
+
+
+    // Private Member Functions
+
+        //- Non-virtual read
+        void readCoeffs();
+
+        //- Set value on a field
+        template<class Type>
+        inline bool constrainType
+        (
+            fvMatrix<Type>& eqn,
+            const word& fieldName
+        ) const;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("fixedValueConstraint");
+
+
+    // Constructors
+
+        //- Construct from components
+        fixedValueConstraint
+        (
+            const word& name,
+            const word& modelType,
+            const fvMesh& mesh,
+            const dictionary& dict
+        );
+
+
+    // Member Functions
+
+        //- Return the list of fields constrained by the fvConstraint
+        virtual wordList constrainedFields() const;
+
+        //- Add a constraint to an equation
+        FOR_ALL_FIELD_TYPES(DEFINE_FV_CONSTRAINT_CONSTRAIN);
+
+        //- Update for mesh motion
+        virtual bool movePoints();
+
+        //- Update topology using the given map
+        virtual void topoChange(const polyTopoChangeMap&);
+
+        //- Update from another mesh using the given map
+        virtual void mapMesh(const polyMeshMap&);
+
+        //- Redistribute or update using the given distribution map
+        virtual void distribute(const polyDistributionMap&);
+
+        //- Read source dictionary
+        virtual bool read(const dictionary& dict);
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace fv
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

tutorials/modules/compressibleMultiphaseVoF/damBreak4phaseLaminar/constant/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (water oil mercury air);
 
-pMin            10000;
-
 sigmas
 (
     (air water)     0.07

tutorials/modules/compressibleVoF/ballValve/system/fvConstraints

@@ -0,0 +1,24 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Version:  dev
+     \\/     M anipulation  |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    format      ascii;
+    class       dictionary;
+    object      fvConstraints;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+boundp
+{
+    type       bound;
+
+    field      p;
+    min        100;
+}
+
+// ************************************************************************* //

tutorials/modules/compressibleVoF/climbingRod/constant/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (liquid air);
 
-pMin        10000;
-
 sigma       0.0309;
 
 // ************************************************************************* //

tutorials/modules/compressibleVoF/cylinder/constant/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (liquid air);
 
-pMin        10000;
-
 sigma       0.0309;
 
 // ************************************************************************* //

tutorials/modules/compressibleVoF/damBreak/constant/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (water air);
 
-pMin        10000;
-
 sigma
 {
     type    liquidProperties;

tutorials/modules/compressibleVoF/depthCharge2D/constant/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (water air);
 
-pMin        10000;
-
 sigma
 {
     type    liquidProperties;

tutorials/modules/compressibleVoF/depthCharge3D/constant/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (water air);
 
-pMin        10000;
-
 sigma       0.07;
 
 // ************************************************************************* //

tutorials/modules/compressibleVoF/plateFilm/constant/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (liquid air);
 
-pMin        10000;
-
 sigma       0.0309;
 
 // ************************************************************************* //

tutorials/modules/compressibleVoF/sloshingTank2D/0/T.air

@@ -7,7 +7,7 @@
 \*---------------------------------------------------------------------------*/
 FoamFile
 {
-    format      ascii;
+    format      binary;
     class       volScalarField;
     location    "0";
     object      T.air;

tutorials/modules/compressibleVoF/sloshingTank2D/0/T.water

@@ -7,7 +7,7 @@
 \*---------------------------------------------------------------------------*/
 FoamFile
 {
-    format      ascii;
+    format      binary;
     class       volScalarField;
     location    "0";
     object      T.water;

tutorials/modules/compressibleVoF/sloshingTank2D/system/fvConstraints

@@ -0,0 +1,24 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Version:  dev
+     \\/     M anipulation  |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    format      ascii;
+    class       dictionary;
+    object      fvConstraints;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+boundp
+{
+    type       bound;
+
+    field      p;
+    min        100;
+}
+
+// ************************************************************************* //

tutorials/modules/multiRegion/CHT/VoFcoolingCylinder2D/constant/fluid/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (water air);
 
-pMin        10000;
-
 sigma
 {
     type    liquidProperties;

tutorials/modules/multiRegion/film/VoFToFilm/constant/VoF/phaseProperties

@@ -16,8 +16,6 @@ FoamFile
 
 phases (liquid air);
 
-pMin        10000;
-
 sigma       0.0309;
 
 // ************************************************************************* //