STYLE: ListExpression: copyright, indenting

Feature grad update

See merge request Development/openfoam!764

applications/test/expressionTemplates/Make/files

@@ -0,0 +1,5 @@
+Test-expressionTemplates-volFields.C
+/* Test-expressionTemplates-pointFields.C */
+/* Test-expressionTemplates-Fields.C */
+
+EXE = $(FOAM_USER_APPBIN)/Test-expressionTemplates

applications/test/expressionTemplates/Make/options

@@ -0,0 +1,11 @@
+EXE_INC = \
+    -O0 \
+    -I$(FOAM_SRC)/meshTools/lnInclude \
+    -I$(FOAM_SRC)/finiteVolume/lnInclude \
+
+EXE_LIBS = \
+/*    -rpath /Volumes/case_sensitive/OpenFOAM/work/feature-et/platforms */ \
+/*    -rpath /Volumes/case_sensitive/OpenFOAM/work/feature-et/platforms/darwin64GccDPInt32Opt/lib */ \
+/*    -rpath /Volumes/case_sensitive/OpenFOAM/work/feature-et/platforms/darwin64GccDPInt32Opt/lib/$(FOAM_MPI)  */\
+    -L/Volumes/case_sensitive/OpenFOAM/work/feature-et/platforms/darwin64GccDPInt32Opt/lib \
+    -lfiniteVolume

applications/test/expressionTemplates/Test-expressionTemplates-pointFields.C

@@ -0,0 +1,126 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2025 M. Janssens
+-------------------------------------------------------------------------------
+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/>.
+
+Application
+    Test-expressionTemplates
+
+\*---------------------------------------------------------------------------*/
+
+#include "Time.H"
+#include "argList.H"
+#include "polyMesh.H"
+#include "pointMesh.H"
+#include "pointFields.H"
+
+using namespace Foam;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+int main(int argc, char *argv[])
+{
+    #include "setRootCase.H"
+
+    #include "createTime.H"
+    #include "createPolyMesh.H"
+
+    {
+        scalarField vals0({1.0, 2.0, 3.0});
+        const Expression::ListConstRefWrap<scalar> wvals0(vals0);
+
+        scalarField vals1;
+        Expression::ListRefWrap<scalar> wvals1(vals1.size(), vals1);
+        wvals1 = wvals0;
+        return 0;
+    }
+
+
+
+
+    const pointMesh& pMesh = pointMesh::New(mesh);
+
+    // Field, dimensionedScalar as List expression
+    {
+        scalarField vals({1.0, 2.0, 3.0});
+        dimensionedScalar d(dimless, 4.0);
+
+        scalarField result(d.expr(vals.size())*vals.expr());
+
+        Pout<< "result:" << result << endl;
+    }
+
+    Info<< "Reading field p\n" << endl;
+    pointScalarField p
+    (
+        IOobject
+        (
+            "pointDisplacement",
+            runTime.timeName(),
+            pMesh.thisDb(),
+            IOobject::MUST_READ,
+            IOobject::AUTO_WRITE
+        ),
+        pMesh
+    );
+
+    pointScalarField result
+    (
+        IOobject
+        (
+            "result",
+            runTime.timeName(),
+            pMesh.thisDb(),
+            IOobject::NO_READ,
+            IOobject::NO_WRITE,
+            IOobject::NO_REGISTER
+        ),
+        pMesh,
+        dimensionedScalar("zero", Foam::sqr(p().dimensions()), 0)
+    );
+
+    // Construct value + dimensions with correct sizing
+    const auto oneField(dimensionedScalar(dimless, 1.0).expr(p));
+
+    // Make expression
+    auto expression = oneField * p.expr() + p.expr();
+
+    // Combine expressions
+    auto newExpression = sqr(expression);
+
+    // Assign values
+    result = newExpression;
+
+    DebugVar(result);
+
+
+    // Construct from expression
+    pointScalarField result2("result2", pMesh, sqrt(p.expr()));
+
+    DebugVar(result2);
+
+    return 0;
+}
+
+
+// ************************************************************************* //

applications/test/expressionTemplates/Test-expressionTemplates-volFields.C

@@ -0,0 +1,451 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2011-2016 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/>.
+
+Application
+    volPointInterpolationTest
+
+\*---------------------------------------------------------------------------*/
+
+#include "Time.H"
+#include "argList.H"
+#include "fvMesh.H"
+#include "ListExpression.H"
+#include "GeometricFieldExpression.H"
+#include "fvCFD.H"
+#include "fvMatrixExpression.H"
+#include <ratio>
+#include <chrono>
+
+using namespace Foam;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+tmp<volScalarField> someFunction(const volScalarField& fld)
+{
+    return fld*1.0001;
+}
+
+
+template<class Type>
+void fusedGaussFvmLaplacian
+(
+    fvMatrix<Type>& fvm,
+    const surfaceInterpolationScheme<scalar>& interpGammaScheme,
+    const fv::snGradScheme<Type>& snGradScheme,
+    const GeometricField<scalar, fvPatchField, volMesh>& gamma,
+    const GeometricField<Type, fvPatchField, volMesh>& vf
+)
+{
+    // Replacement for gaussLaplacianScheme::fvmLaplacian with scalar gamma
+    typedef GeometricField<Type, fvsPatchField, surfaceMesh> surfaceType;
+
+    const auto& mesh = vf.mesh();
+
+    // Expression for weights
+    const auto weights = interpGammaScheme.weights(gamma).expr();
+
+    // Expression for gamma_face * magSf
+    const auto gammaMagSf =
+        Expression::interpolate(gamma.expr(), weights, mesh)
+      * mesh.magSf().expr();
+
+    // Expression for deltaCoeffs
+    const auto deltaCoeffs = snGradScheme.deltaCoeffs(vf).expr();
+
+    // Construct matrix
+    Expression::fvmLaplacianUncorrected(fvm, gammaMagSf, deltaCoeffs);
+
+    if (snGradScheme.corrected())
+    {
+        // Wrap correction
+        const auto corr(snGradScheme.correction(vf).expr());
+        const auto V = mesh.V().expr();
+
+        if (mesh.fluxRequired(vf.name()))
+        {
+            fvm.faceFluxCorrectionPtr() = std::make_unique<surfaceType>
+            (
+                IOobject
+                (
+                    "faceFluxCorr",
+                    mesh.time().timeName(),
+                    mesh,
+                    IOobject::NO_READ,
+                    IOobject::NO_WRITE,
+                    IOobject::NO_REGISTER
+                ),
+                mesh,
+                gamma.dimensions()
+               *mesh.magSf().dimensions()
+               *corr.data().dimensions()
+            );
+            auto& faceFluxCorr = *fvm.faceFluxCorrectionPtr();
+            faceFluxCorr = gammaMagSf*corr;
+
+            fvm.source() =
+                fvm.source().expr()
+              - (
+                    V * fvc::div
+                    (
+                        faceFluxCorr
+                    )().primitiveField().expr()
+                );
+        }
+        else
+        {
+            // Temporary field
+            surfaceType faceFluxCorr
+            (
+                IOobject
+                (
+                    "faceFluxCorr",
+                    mesh.time().timeName(),
+                    mesh,
+                    IOobject::NO_READ,
+                    IOobject::NO_WRITE,
+                    IOobject::NO_REGISTER
+                ),
+                mesh,
+                gamma.dimensions()
+               *mesh.magSf().dimensions()
+               *corr.data().dimensions()
+            );
+            faceFluxCorr = gammaMagSf*corr;
+
+            fvm.source() =
+                fvm.source().expr()
+              - (
+                    V * fvc::div
+                    (
+                        faceFluxCorr
+                    )().primitiveField().expr()
+                );
+        }
+    }
+}
+
+
+using namespace std::chrono;
+
+int main(int argc, char *argv[])
+{
+    #include "setRootCase.H"
+    #include "createTime.H"
+    #include "createMesh.H"
+
+    Info<< "Reading field p\n" << endl;
+    volScalarField p
+    (
+        IOobject
+        (
+            "p",
+            runTime.timeName(),
+            mesh.thisDb(),
+            IOobject::MUST_READ,
+            IOobject::AUTO_WRITE
+        ),
+        mesh
+    );
+    
+    {
+        volScalarField p2("p2", p);
+        DebugVar(p2.boundaryFieldRef());
+    
+        for (auto& pf : p.boundaryFieldRef())
+        {
+            scalarField newVals(pf.size());
+            forAll(pf, i)
+            {
+                newVals[i] = scalar(i);
+            }
+            pf == newVals;
+        }
+
+        //std::vector<const scalarField*> ptrs;
+        // List<const scalarField*> ptrs;
+        // for (const auto& pp : p.boundaryField())
+        // {
+        //     ptrs.push_back(&pp);
+        // }
+        DebugVar(sizeof(long));
+        DebugVar(p.boundaryField());
+        Expression::ListsConstRefWrap<scalarField> expr(p.boundaryField());
+
+        const auto twoA = expr + expr;
+        Expression::ListsRefWrap<scalarField> expr2(p2.boundaryFieldRef());
+        Pout<< "**before assignment twoA:" << twoA.size()
+            << " expr2:" << expr2.size() << endl;
+        expr2 = twoA;
+        Pout<< "**after assignment twoA:" << twoA.size()
+            << " expr2:" << expr2.size() << endl;
+        DebugVar(p2.boundaryField());
+        // forAll(expr, i)
+        // {
+        //     Pout<< "i:" << i
+        //         //<< " expr:" << expr[i]
+        //         //<< " twoA:" << twoA[i]
+        //         << " expr2:" << expr2[i]
+        //         << endl;
+        // }
+        return 0;
+    }
+
+    {
+        //DebugVar(linearInterpolate(p));
+        //auto tweights = linear<scalar>(mesh).weights(p);
+        //DebugVar(tweights);
+
+        surfaceScalarField result
+        (
+            IOobject
+            (
+                "result",
+                runTime.timeName(),
+                mesh.thisDb(),
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                IOobject::NO_REGISTER
+            ),
+            mesh,
+            dimensionedScalar(p.dimensions(), 0)
+        );
+        //result = Expression::interpolate
+        //(
+        //    p.expr(),
+        //    tweights().expr(),
+        //    mesh
+        //);
+
+        result = Expression::linearInterpolate(p.expr(), mesh);
+
+
+        DebugVar(result);
+
+        return 0;
+    }
+
+
+
+    volScalarField p2
+    (
+        IOobject
+        (
+            "p",
+            runTime.timeName(),
+            mesh.thisDb(),
+            IOobject::MUST_READ,
+            IOobject::AUTO_WRITE,
+            IOobject::NO_REGISTER
+        ),
+        mesh
+    );
+
+    // Expresions of volFields
+    {
+        volScalarField result
+        (
+            IOobject
+            (
+                "result",
+                runTime.timeName(),
+                mesh.thisDb(),
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                IOobject::NO_REGISTER
+            ),
+            mesh,
+            dimensionedScalar(p.dimensions(), 0)
+        );
+
+        {
+            Pout<< "No expression templates:" << endl;
+            const high_resolution_clock::time_point t1 =
+                high_resolution_clock::now();
+            result = p + p2;
+            const high_resolution_clock::time_point t2 =
+                high_resolution_clock::now();
+            const duration<double> time_span = t2 - t1;
+            Pout<< "Operation time:" << time_span.count() << endl;
+        }
+        {
+            Pout<< "With expression templates:" << endl;
+            const high_resolution_clock::time_point t1 =
+                high_resolution_clock::now();
+            result = p.expr() + p2.expr();
+            const high_resolution_clock::time_point t2 =
+                high_resolution_clock::now();
+            const duration<double> time_span = t2 - t1;
+            Pout<< "Operation time:" << time_span.count() << endl;
+        }
+
+//        const auto oldDimensions = p.dimensions();
+//        p.dimensions().reset(dimless);
+//        p2.dimensions().reset(dimless);
+//        result.dimensions().reset(dimless);
+//        {
+//
+//            Pout<< "Complex expression : No expression templates:" << endl;
+//            const high_resolution_clock::time_point t1 =
+//                high_resolution_clock::now();
+//            result = cos(p + 0.5*sqrt(p2-sin(p)));
+//            const high_resolution_clock::time_point t2 =
+//                high_resolution_clock::now();
+//            const duration<double> time_span = t2 - t1;
+//            Pout<< "Operation time:" << time_span.count() << endl;
+//        }
+//        {
+//            Pout<< "Complex expression : With expression templates:" << endl;
+//            const high_resolution_clock::time_point t1 =
+//                high_resolution_clock::now();
+//            const auto zeroDotFive
+//            (
+//                dimensionedScalar(dimless, 0.5).expr(p)
+//            );
+//            result = cos(p.expr() + zeroDotFive*sqrt(p2.expr()-sin(p.expr())));
+//            const high_resolution_clock::time_point t2 =
+//                high_resolution_clock::now();
+//            const duration<double> time_span = t2 - t1;
+//            Pout<< "Operation time:" << time_span.count() << endl;
+//        }
+//        p.dimensions().reset(oldDimensions);
+//        p2.dimensions().reset(oldDimensions);
+//        result.dimensions().reset(oldDimensions);
+
+        return 0;
+//        auto expression = someFunction(p).expr() + someFunction(p).expr();
+//        result = expression;
+//        DebugVar(result);
+    }
+    {
+        volScalarField result
+        (
+            IOobject
+            (
+                "result",
+                runTime.timeName(),
+                mesh.thisDb(),
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                IOobject::NO_REGISTER
+            ),
+            mesh,
+            dimensionedScalar(p.dimensions(), 0)
+        );
+        auto expression = someFunction(p).expr() + someFunction(p).expr();
+        result = expression;
+        DebugVar(result);
+    }
+
+    // Expresions of volFields
+    {
+        volScalarField result
+        (
+            "result",
+            mesh,
+            sqr(p.expr() + p.expr())
+        );
+        DebugVar(result);
+    }
+    {
+        // Fill p with some values
+        forAll(p, celli)
+        {
+            p[celli] = celli;
+        }
+        p.correctBoundaryConditions();
+
+        // Interpolate to surface field
+        surfaceScalarField result
+        (
+            "result",
+            mesh,
+            Expression::interpolate    //<volExpr, surfaceExpr>
+            (
+                p.expr(),
+                mesh.surfaceInterpolation::weights().expr(),
+                mesh
+            )
+        );
+        DebugVar(result);
+    }
+    {
+        // For testing as a replacement of laplacian weights
+        const volScalarField gamma
+        (
+            IOobject
+            (
+                "gamma",
+                runTime.timeName(),
+                mesh,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                IOobject::NO_REGISTER
+            ),
+            mesh,
+            dimensionedScalar(dimless, 1.0)
+        );
+
+        fvMatrix<scalar> fvm
+        (
+            p,
+            gamma.dimensions()*mesh.magSf().dimensions()*p.dimensions()
+        );
+
+        const linear<scalar> interpGammaScheme(mesh);
+        const fv::correctedSnGrad<scalar> snGradScheme(mesh);
+
+        fusedGaussFvmLaplacian
+        (
+            fvm,
+            interpGammaScheme,
+            snGradScheme,
+            gamma,
+            p
+        );
+
+        DebugVar(fvm.source());
+    }
+
+
+
+    // Expressions of fvMatrix
+    {
+        tmp<fvMatrix<scalar>> tm0(fvm::laplacian(p));
+        const fvMatrix<scalar>& m0 = tm0();
+        DebugVar(m0.dimensions());
+
+        tmp<fvMatrix<scalar>> tm1(fvm::laplacian(p));
+        const fvMatrix<scalar>& m1 = tm1();
+        DebugVar(m1.dimensions());
+
+        fvMatrix<scalar> m2(p, m0.expr() + m1.expr());
+        DebugVar(m2.dimensions());
+    }
+
+    return 0;
+}
+
+
+// ************************************************************************* //

applications/test/faMeshesRegistry/Test-faMeshesRegistry.cxx

@@ -49,7 +49,8 @@ int main(int argc, char *argv[])
 
     Info<< "mesh 0: " << mesh.sortedNames() << nl;
 
-    auto& reg = const_cast<faMeshesRegistry&>(faMeshesRegistry::New(mesh));
+    faMeshesRegistry& reg =
+        const_cast<faMeshesRegistry&>(faMeshesRegistry::New(mesh));
 
     // faMeshesRegistry faReg = faMeshesRegistry(mesh);
 

applications/test/foamToEnsight-check/Make/files

@@ -1,3 +1,3 @@
-foamToEnsight-check.cxx
+foamToEnsight-check.C
 
 EXE = $(FOAM_USER_APPBIN)/foamToEnsight-check

applications/test/foamToEnsight-check/foamToEnsight-check.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2022-2025 OpenCFD Ltd.
+    Copyright (C) 2022-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -203,7 +203,6 @@ int main(int argc, char *argv[])
     argList::addVerboseOption();
 
     #include "addAllRegionOptions.H"
-    #include "addAllFaRegionOptions.H"
 
     argList::addBoolOption
     (
@@ -252,14 +251,6 @@ int main(int argc, char *argv[])
     // Handle -allRegions, -regions, -region
     #include "getAllRegionOptions.H"
 
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
-
-    if (!doFiniteArea)
-    {
-        areaRegionNames.clear();  // For consistency
-    }
-
     // ------------------------------------------------------------------------
 
     #include "createNamedMeshes.H"
@@ -268,8 +259,8 @@ int main(int argc, char *argv[])
     /// #include "createMeshAccounting.H"
 
     PtrList<ensightMesh> ensightMeshes(regionNames.size());
-    List<PtrList<faMesh>> meshesFa(regionNames.size());
-    List<PtrList<ensightFaMesh>> ensightMeshesFa(regionNames.size());
+    PtrList<faMesh> meshesFa(regionNames.size());
+    PtrList<ensightFaMesh> ensightMeshesFa(regionNames.size());
 
     forAll(regionNames, regioni)
     {
@@ -282,32 +273,21 @@ int main(int argc, char *argv[])
         );
         ensightMeshes[regioni].verbose(optVerbose);
 
-        if (!doFiniteArea)
+
+        if (doFiniteArea)
         {
-            continue;
-        }
-
-        meshesFa[regioni].resize_null(areaRegionNames.size());
-        ensightMeshesFa[regioni].resize_null(areaRegionNames.size());
-
-        autoPtr<faMesh> faMeshPtr(faMesh::TryNew(mesh));
-
-        forAll(areaRegionNames, areai)
-        {
-            const word& areaName = areaRegionNames[areai];
-
-            autoPtr<faMesh> faMeshPtr(faMesh::TryNew(areaName, mesh));
+            autoPtr<faMesh> faMeshPtr(faMesh::TryNew(mesh));
 
             if (faMeshPtr)
             {
-                meshesFa[regioni].set(areai, std::move(faMeshPtr));
+                meshesFa.set(regioni, std::move(faMeshPtr));
 
-                ensightMeshesFa[regioni].set
+                ensightMeshesFa.set
                 (
-                    areai,
-                    new ensightFaMesh(meshesFa[regioni][areai])
+                    regioni,
+                    new ensightFaMesh(meshesFa[regioni])
                 );
-                ensightMeshesFa[regioni][areai].verbose(optVerbose);
+                ensightMeshesFa[regioni].verbose(optVerbose);
             }
         }
     }
@@ -315,7 +295,7 @@ int main(int argc, char *argv[])
     // ------------------------------------------------------------------------
 
 
-    if (UPstream::master())
+    if (Pstream::master())
     {
         Info<< "Checking " << timeDirs.size() << " time steps" << nl;
     }
@@ -337,20 +317,17 @@ int main(int argc, char *argv[])
             auto& ensMesh = ensightMeshes[regioni];
 
             // Finite-area (can be missing)
-            auto& ensFaMeshes = ensightMeshesFa[regioni];
+            auto* ensFaMeshPtr = ensightMeshesFa.get(regioni);
 
             if (moving)
             {
                 ensMesh.expire();
                 ensMesh.correct();
 
-                forAll(areaRegionNames, areai)
+                if (ensFaMeshPtr)
                 {
-                    if (auto* ensFaMeshPtr = ensFaMeshes.get(areai))
-                    {
-                        ensFaMeshPtr->expire();
-                        ensFaMeshPtr->correct();
-                    }
+                    ensFaMeshPtr->expire();
+                    ensFaMeshPtr->correct();
                 }
             }
 
@@ -363,15 +340,9 @@ int main(int argc, char *argv[])
 
                 printInfo(ensMesh, optVerbose);
 
-                // finite-area
-                forAll(areaRegionNames, areai)
+                if (ensFaMeshPtr)
                 {
-                    auto* ensFaMeshPtr = ensFaMeshes.get(areai);
-
-                    if (ensFaMeshPtr)
-                    {
-                        printInfo(*ensFaMeshPtr, optVerbose);
-                    }
+                    printInfo(*ensFaMeshPtr, optVerbose);
                 }
             }
         }

applications/utilities/finiteArea/checkFaMesh/checkFaMesh.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
-    Copyright (C) 2021-2025 OpenCFD Ltd.
+    Copyright (C) 2021-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -28,7 +28,7 @@ Application
     makeFaMesh
 
 Description
-    Check a finite-area mesh
+    Check a finiteArea mesh
 
 Original Authors
     Zeljko Tukovic, FAMENA
@@ -39,7 +39,6 @@ Original Authors
 #include "Time.H"
 #include "argList.H"
 #include "faMesh.H"
-#include "faMeshTools.H"
 #include "polyMesh.H"
 #include "areaFaMesh.H"
 #include "edgeFaMesh.H"
@@ -48,7 +47,7 @@ Original Authors
 #include "processorFaPatch.H"
 #include "foamVtkIndPatchWriter.H"
 #include "foamVtkLineWriter.H"
-#include "regionProperties.H"
+#include "faMeshTools.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -60,7 +59,7 @@ int main(int argc, char *argv[])
 {
     argList::addNote
     (
-        "Check a finite-area mesh"
+        "Check a finiteArea mesh"
     );
 
     argList::addBoolOption
@@ -78,15 +77,9 @@ int main(int argc, char *argv[])
     );
 
     #include "addRegionOption.H"
-    #include "addAllFaRegionOptions.H"
+    #include "addFaRegionOption.H"
     #include "setRootCase.H"
     #include "createTime.H"
-
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
-
-    // ------------------------------------------------------------------------
-
     #include "createNamedPolyMesh.H"
 
     int geometryOrder(1);
@@ -98,41 +91,16 @@ int main(int argc, char *argv[])
         faMesh::geometryOrder(geometryOrder);
     }
 
-    for (const word& areaName : areaRegionNames)
+    #include "createNamedFaMesh.H"
+
+    Info<< "Time = " << runTime.timeName() << nl << endl;
+
+    // Mesh information (verbose)
+    faMeshTools::printMeshChecks(aMesh);
+
+    if (args.found("write-vtk"))
     {
-        Info<< "Create faMesh";
-        if (!polyMesh::regionName(areaName).empty())
-        {
-            Info<< " [" << areaName << "]";
-        }
-        Info<< " for time = " << runTime.timeName() << nl;
-
-        autoPtr<faMesh> faMeshPtr(faMesh::TryNew(areaName, mesh));
-
-        if (!faMeshPtr)
-        {
-            Info<< "    ...failed to create area-mesh";
-            if (!polyMesh::regionName(areaName).empty())
-            {
-                Info<< " [" << areaName << "]";
-            }
-            Info<< endl;
-            continue;
-        }
-        else
-        {
-            Info<< endl;
-        }
-
-        const auto& aMesh = faMeshPtr();
-
-        // Mesh information (verbose)
-        faMeshTools::printMeshChecks(aMesh);
-
-        if (args.found("write-vtk"))
-        {
-            #include "faMeshWriteVTK.H"
-        }
+        #include "faMeshWriteVTK.H"
     }
 
     Info<< "\nEnd\n" << endl;

applications/utilities/finiteArea/checkFaMesh/faMeshWriteVTK.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2021-2025 OpenCFD Ltd.
+    Copyright (C) 2021-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -15,16 +15,6 @@ Description
 
 \*---------------------------------------------------------------------------*/
 
-// The base name for output files
-word vtkBaseFileName(aMesh.regionName());
-if (polyMesh::regionName(vtkBaseFileName).empty())
-{
-    vtkBaseFileName = "finiteArea";
-}
-
-Info<< nl;
-Info<< "Write faMesh in vtk format:" << nl;
-
 {
     // finiteArea - faces
     vtk::uindirectPatchWriter writer
@@ -33,7 +23,7 @@ Info<< "Write faMesh in vtk format:" << nl;
         // vtk::formatType::INLINE_ASCII,
         fileName
         (
-            aMesh.time().globalPath() / vtkBaseFileName
+            aMesh.time().globalPath() / "finiteArea"
         )
     );
 
@@ -42,7 +32,7 @@ Info<< "Write faMesh in vtk format:" << nl;
     globalIndex procAddr(aMesh.nFaces());
     labelList cellIDs;
 
-    if (UPstream::master())
+    if (Pstream::master())
     {
         cellIDs.resize(procAddr.totalSize());
         for (const labelRange& range : procAddr.ranges())
@@ -63,7 +53,8 @@ Info<< "Write faMesh in vtk format:" << nl;
     writer.beginPointData(1);
     writer.write("normal", aMesh.pointAreaNormals());
 
-    Info<< "    " << writer.output().name() << nl;
+    Info<< nl
+        << "Wrote faMesh in vtk format: " << writer.output().name() << nl;
 }
 
 {
@@ -75,7 +66,7 @@ Info<< "Write faMesh in vtk format:" << nl;
         // vtk::formatType::INLINE_ASCII,
         fileName
         (
-            aMesh.time().globalPath() / (vtkBaseFileName + "-edges")
+            aMesh.time().globalPath() / "finiteArea-edges"
         )
     );
 
@@ -97,7 +88,8 @@ Info<< "Write faMesh in vtk format:" << nl;
     writer.beginPointData(1);
     writer.write("normal", aMesh.pointAreaNormals());
 
-    Info<< "    " << writer.output().name() << nl;
+    Info<< nl
+        << "Wrote faMesh in vtk format: " << writer.output().name() << nl;
 }
 
 {
@@ -116,7 +108,7 @@ Info<< "Write faMesh in vtk format:" << nl;
         // vtk::formatType::INLINE_ASCII,
         fileName
         (
-            aMesh.time().globalPath() / (vtkBaseFileName + "-edgesCentres")
+            aMesh.time().globalPath() / "finiteArea-edgesCentres"
         )
     );
 
@@ -142,7 +134,8 @@ Info<< "Write faMesh in vtk format:" << nl;
         writer.write("normal", fld);
     }
 
-    Info<< "    " << writer.output().name() << nl;
+    Info<< nl
+        << "Wrote faMesh in vtk format: " << writer.output().name() << nl;
 }
 
 

applications/utilities/finiteArea/makeFaMesh/checkPatchTopology.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2023-2025 OpenCFD Ltd.
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -15,7 +15,7 @@ Description
 
 Input
     mesh (polyMesh)
-    meshDefDict (system/finite-area/faMeshDefinition)
+    meshDefDict (system/faMeshDefintion)
 
 \*---------------------------------------------------------------------------*/
 
@@ -25,16 +25,13 @@ Input
 
     const polyBoundaryMesh& pbm = mesh.boundaryMesh();
 
-    labelList patchIDs;
+    wordRes polyPatchNames;
+    meshDefDict.readIfPresent("polyMeshPatches", polyPatchNames);
 
-    if
+    const labelList patchIDs
     (
-        wordRes select;
-        meshDefDict.readIfPresent("polyMeshPatches", select)
-    )
-    {
-        patchIDs = pbm.indices(select, true);  // useGroups
-    }
+        pbm.indices(polyPatchNames, true)  // useGroups
+    );
 
     label nFaceLabels = 0;
     for (const label patchi : patchIDs)

applications/utilities/finiteArea/makeFaMesh/findMeshDefinitionDict.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2021-2025 OpenCFD Ltd.
+    Copyright (C) 2021-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -13,18 +13,6 @@ License
 Description
     Search for the appropriate faMeshDefinition dictionary...
 
-    Expects to find a faMeshDefinition file in a location specified
-    by the command-line option, or one of the standard locations.
-
-    For default area region (region0):
-      (1) system/finite-area/faMeshDefinition
-      (2) system/faMeshDefinition  [legacy location - v2312 and earlier]
-
-    For a named area region:
-      (1) system/finite-area/<area-name>/faMeshDefinition
-      (2) system/finite-area/faMeshDefinition.<area-name>
-          [symmetric with faOptions]
-
 Required Classes
     - Foam::polyMesh
     - Foam::IOdictionary
@@ -36,185 +24,81 @@ Required Variables
     - runTime [Time]
 
 Provided Variables
-    - faMeshDefinitionPtr [autoPtr<IOdictionary>]
-
-If the dictionary cannot be found, exits with an error message or
-reports a warning (dry-run mode)
+    - meshDefDict [IOdictionary]
+    - meshDictPtr [autoPtr<IOdictionary>]
 
 \*---------------------------------------------------------------------------*/
 
 const word dictName("faMeshDefinition");
 
-autoPtr<IOdictionary> faMeshDefinitionPtr;
+autoPtr<IOdictionary> meshDictPtr;
 
 {
-    // Exit unless dry-run?
-    const bool exitOnFailure = (!args.dryRun());
+    fileName dictPath;
+    const word& regionDir = Foam::polyMesh::regionName(regionName);
+    const word& areaRegionDir = Foam::polyMesh::regionName(areaRegionName);
 
-    const word& regionDir = polyMesh::regionName(regionName);
-    const word& areaRegionDir = polyMesh::regionName(areaRegionName);
-
-    // Canonical location
-    fileName dictPath
-    (
-        runTime.system()/regionDir
-      / faMesh::prefix()/areaRegionDir/dictName
-    );
-
-
-    // Dictionary specified on the command-line ...
-    const bool specified = args.readIfPresent("dict", dictPath);
-
-    if (specified)
+    if (args.readIfPresent("dict", dictPath))
     {
+        // Dictionary specified on the command-line ...
+
         if (isDir(dictPath))
         {
             dictPath /= dictName;
         }
     }
+    else if
+    (
+        // Dictionary under system/faMeshDefinition ?
+        // (v2312 and earlier)
 
+        areaRegionDir.empty()
+     && exists
+        (
+            runTime.path()/runTime.caseSystem()
+          / regionDir/faMesh::meshSubDir/dictName
+        )
+    )
+    {
+        // Dictionary present directly in system/ (v2312 and earlier)
+
+        dictPath = runTime.system()/regionDir/dictName;
+    }
+    else
+    {
+        // Use system/finite-area/ directory, with region qualifications
+
+        dictPath =
+        (
+            runTime.system()/regionDir
+          / faMesh::prefix()/areaRegionDir/dictName
+        );
+    }
 
     IOobject meshDictIO
     (
         dictPath,
         runTime,
-        IOobjectOption::MUST_READ,
-        IOobjectOption::NO_WRITE,
-        IOobjectOption::NO_REGISTER,
+        IOobject::MUST_READ,
+        IOobject::NO_WRITE,
+        IOobject::NO_REGISTER,
         true    // is globalObject
     );
 
-    refPtr<IOobject> meshDictIOPtr;
-
-    bool foundIOobject = meshDictIO.typeHeaderOk<IOdictionary>(true);
-
-    // For reporting any alternative locations
-    dictPath.clear();
-
-    if (!foundIOobject && !specified)
+    if (!meshDictIO.typeHeaderOk<IOdictionary>(true))
     {
-        if (!areaRegionDir.empty())
-        {
-            // Alternative location
-            // - system/finite-area/faMeshDefinition.<area-name>
-
-            dictPath =
-            (
-                runTime.system()/regionDir
-              / faMesh::prefix()/IOobject::groupName(dictName, areaRegionDir)
-            );
-        }
-        else
-        {
-            // legacy location (v2312 and earlier)
-            // - system/faMeshDefinition
-
-            dictPath = runTime.system()/regionDir/dictName;
-        }
-
-        if (!dictPath.empty())
-        {
-            auto ioptr = autoPtr<IOobject>::New
-            (
-                dictPath,
-                runTime,
-                IOobjectOption::MUST_READ,
-                IOobjectOption::NO_WRITE,
-                IOobjectOption::NO_REGISTER,
-                true    // is globalObject
-            );
-
-            foundIOobject =
-            (
-                ioptr && ioptr->typeHeaderOk<IOdictionary>(true)
-            );
-
-            if (foundIOobject)
-            {
-                // Use if found
-                meshDictIOPtr = std::move(ioptr);
-            }
-
-            // Generally retain dictPath for error messages,
-            // but don't mention the really old legacy location
-            if (areaRegionDir.empty())
-            {
-                dictPath.clear();
-            }
-        }
+        FatalErrorInFunction
+            << meshDictIO.objectPath() << nl
+            << exit(FatalError);
     }
 
-    // Alternative location or regular location?
-    if (!meshDictIOPtr)
-    {
-        meshDictIOPtr.cref(meshDictIO);
-    }
-    const auto& io = meshDictIOPtr();
+    Info<< "Creating faMesh from definition: "
+        << meshDictIO.objectRelPath() << endl;
 
-
-    // Handle final success or failure
-    if (foundIOobject)
-    {
-        Info<< "----------------" << nl
-            << "Using area-mesh definition";
-        if (!areaRegionDir.empty())
-        {
-            Info<< " [" << areaRegionName << "]";
-        }
-
-        Info<< nl
-            << "    " << io.objectRelPath() << nl << endl;
-
-        faMeshDefinitionPtr = autoPtr<IOdictionary>::New(io);
-    }
-    else
-    {
-        // Failure
-
-        if (exitOnFailure)
-        {
-            auto& err =
-                FatalErrorInFunction
-                << "Did not find area-mesh definition";
-
-            if (!areaRegionDir.empty())
-            {
-                err<< " [" << areaRegionName << "]";
-            }
-
-            err << nl
-                << "    " << io.objectRelPath() << nl;
-
-            if (!dictPath.empty())
-            {
-                err << "    " << dictPath << nl;
-            }
-
-            FatalError<< exit(FatalError);
-        }
-        else
-        {
-            // dry-run: warning
-            auto& err =
-                Warning << nl
-                << "----------------" << nl
-                << "Did not find area-mesh definition";
-
-            if (!areaRegionDir.empty())
-            {
-                err << " [" << areaRegionName << "]";
-            }
-
-            err << nl
-                << "    " << io.objectRelPath() << nl;
-
-            if (!dictPath.empty())
-            {
-                err << "    " << dictPath << nl;
-            }
-        }
-    }
+    meshDictPtr = autoPtr<IOdictionary>::New(meshDictIO);
 }
 
+IOdictionary& meshDefDict = *meshDictPtr;
+
 
 // ************************************************************************* //

applications/utilities/finiteArea/makeFaMesh/makeFaMesh.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
-    Copyright (C) 2021-2025 OpenCFD Ltd.
+    Copyright (C) 2021-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -40,6 +40,7 @@ Original Authors
 
 #include "Time.H"
 #include "argList.H"
+#include "OSspecific.H"
 #include "faMesh.H"
 #include "faMeshTools.H"
 #include "IOdictionary.H"
@@ -52,7 +53,6 @@ Original Authors
 #include "PtrListOps.H"
 #include "foamVtkLineWriter.H"
 #include "foamVtkIndPatchWriter.H"
-#include "regionProperties.H"
 #include "syncTools.H"
 #include "OBJstream.H"
 
@@ -104,14 +104,12 @@ int main(int argc, char *argv[])
     );
 
     #include "addRegionOption.H"
-    #include "addAllFaRegionOptions.H"
-
+    #include "addFaRegionOption.H"
     #include "setRootCase.H"
     #include "createTime.H"
     #include "createNamedPolyMesh.H"
 
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
+    #include "getFaRegionOption.H"
 
     const bool doDecompose = !args.found("no-decompose");
     const bool doDecompFields = !args.found("no-fields");
@@ -125,83 +123,56 @@ int main(int argc, char *argv[])
         Info<< "Skip decompose of finiteArea fields" << nl;
     }
 
-    // ------------------------------------------------------------------------
+    // Reading faMeshDefinition dictionary
+    #include "findMeshDefinitionDict.H"
 
-    for (const word& areaRegionName : areaRegionNames)
+    // Inject/overwrite name for optional 'empty' patch
+    word patchName;
+    if (args.readIfPresent("empty-patch", patchName))
     {
-        // Reading faMeshDefinition dictionary
-        #include "findMeshDefinitionDict.H"
+        meshDefDict.add("emptyPatch", patchName, true);
+    }
 
-        if (!faMeshDefinitionPtr)
-        {
-            if (args.dryRun())
-            {
-                break;
-            }
-            else
-            {
-                FatalErrorInFunction
-                    << "Did not find area-mesh definition"<< nl
-                    << exit(FatalError);
-            }
-        }
+    // Preliminary checks
+    #include "checkPatchTopology.H"
 
-        auto& meshDefDict = (*faMeshDefinitionPtr);
+    Info << "Create areaMesh";
+    if (!Foam::polyMesh::regionName(areaRegionName).empty())
+    {
+        Foam::Info << ' ' << areaRegionName;
+    }
+    Info << " for polyMesh at time = " << runTime.timeName() << nl;
 
+    // Create
+    faMesh aMesh(areaRegionName, mesh, meshDefDict);
 
-        // Inject/overwrite name for optional 'empty' patch
-        if (word name; args.readIfPresent("empty-patch", name))
-        {
-            meshDefDict.add("emptyPatch", name, true);
-        }
+    // Mesh information (less verbose)
+    faMeshTools::printMeshChecks(aMesh, 0);
 
-        // Preliminary checks
-        #include "checkPatchTopology.H"
+    if (args.found("write-edges-obj"))
+    {
+        #include "faMeshWriteEdgesOBJ.H"
+    }
 
-        Info<< "Create area-mesh";
-        if (!polyMesh::regionName(areaRegionName).empty())
-        {
-            Info<< " [" << areaRegionName << "]";
-        }
-        Info<< " with polyMesh at time = " << runTime.timeName() << nl;
+    if (args.found("write-vtk"))
+    {
+        #include "faMeshWriteVTK.H"
+    }
 
-        // Create
-        faMesh aMesh(areaRegionName, mesh, meshDefDict);
+    if (args.dryRun())
+    {
+        Info<< "\ndry-run: not writing mesh or decomposing fields\n" << nl;
+    }
+    else
+    {
+        // More precision (for points data)
+        IOstream::minPrecision(10);
 
-        // Mesh information (less verbose)
-        faMeshTools::printMeshChecks(aMesh, 0);
+        Info<< nl << "Write finite area mesh." << nl;
+        aMesh.write();
 
-        if (args.found("write-edges-obj"))
-        {
-            #include "faMeshWriteEdgesOBJ.H"
-        }
-
-        if (args.found("write-vtk"))
-        {
-            #include "faMeshWriteVTK.H"
-        }
-
-        if (args.dryRun())
-        {
-            Info<< "\ndry-run: not writing mesh or decomposing fields\n" << nl;
-        }
-        else
-        {
-            // More precision (for points data)
-            IOstream::minPrecision(10);
-
-            Info<< nl << "Write finite area mesh";
-            if (const word& name = aMesh.regionName(); !name.empty())
-            {
-                Info<< " [" << name << "]";
-            }
-            Info<< nl;
-
-            aMesh.write();
-
-            Info<< endl;
-            #include "decomposeFaFields.H"
-        }
+        Info<< endl;
+        #include "decomposeFaFields.H"
     }
 
     Info<< "\nEnd\n" << endl;

applications/utilities/parallelProcessing/decomposePar/decomposePar.C

@@ -334,7 +334,6 @@ int main(int argc, char *argv[])
     );
 
     #include "addAllRegionOptions.H"
-    #include "addAllFaRegionOptions.H"
 
     argList::addDryRunOption
     (
@@ -443,6 +442,7 @@ int main(int argc, char *argv[])
     bool decomposeFieldsOnly = args.found("fields");
     bool forceOverwrite      = args.found("force");
 
+
     // Set time from database
     #include "createTime.H"
 
@@ -491,17 +491,9 @@ int main(int argc, char *argv[])
         decompDictFile = runTime.globalPath()/decompDictFile;
     }
 
-    // Handle -allRegions, -regions, -region
+    // Get region names
     #include "getAllRegionOptions.H"
 
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
-
-    if (!doFiniteArea)
-    {
-        areaRegionNames.clear();  // For consistency
-    }
-
     const bool optRegions =
         (regionNames.size() != 1 || regionNames[0] != polyMesh::defaultRegion);
 
@@ -821,76 +813,56 @@ int main(int argc, char *argv[])
 
                 // Field objects at this time
                 IOobjectList objects;
-
-                // faMesh fields - can have multiple finite-area per volume
-                HashTable<IOobjectList> faObjects;
+                IOobjectList faObjects;
 
                 if (doDecompFields)
                 {
                     // List of volume mesh objects for this instance
                     objects = IOobjectList(mesh, runTime.timeName());
 
+                    // List of area mesh objects (assuming single region)
+                    faObjects = IOobjectList
+                    (
+                        mesh.time(),
+                        runTime.timeName(),
+                        faMesh::dbDir(mesh, word::null),
+                        IOobjectOption::NO_REGISTER
+                    );
+
                     // Ignore generated fields: (cellDist)
                     objects.remove("cellDist");
-
-                    // Lists of finite-area fields
-                    faObjects.reserve(areaRegionNames.size());
-
-                    for (const word& areaName : areaRegionNames)
-                    {
-                        // The finite-area objects for this area region
-                        IOobjectList objs
-                        (
-                            faMesh::Registry(mesh),
-                            runTime.timeName(),
-                            polyMesh::regionName(areaName),
-                            IOobjectOption::NO_REGISTER
-                        );
-
-                        if (!objs.empty())
-                        {
-                            faObjects.emplace_set(areaName, std::move(objs));
-                        }
-                    }
                 }
 
                 // Finite area handling
-                // - all area regions use the same volume decomposition
-
-                HashPtrTable<faMeshDecomposition> faMeshDecompHashes;
+                autoPtr<faMeshDecomposition> faMeshDecompPtr;
                 if (doFiniteArea)
                 {
                     const word boundaryInst =
                         mesh.time().findInstance(mesh.meshDir(), "boundary");
 
-                    for (const word& areaName : areaRegionNames)
-                    {
-                        IOobject io
-                        (
-                            "faBoundary",
-                            boundaryInst,
-                            faMesh::meshDir(mesh, areaName),
-                            mesh.time(),
-                            IOobject::READ_IF_PRESENT,
-                            IOobject::NO_WRITE,
-                            IOobject::NO_REGISTER
-                        );
+                    IOobject io
+                    (
+                        "faBoundary",
+                        boundaryInst,
+                        faMesh::meshDir(mesh, word::null),
+                        mesh.time(),
+                        IOobject::READ_IF_PRESENT,
+                        IOobject::NO_WRITE,
+                        IOobject::NO_REGISTER
+                    );
 
-                        if (io.typeHeaderOk<faBoundaryMesh>(true))
-                        {
-                            // Always based on the volume decomposition!
-                            faMeshDecompHashes.set
+                    if (io.typeHeaderOk<faBoundaryMesh>(true))
+                    {
+                        // Always based on the volume decomposition!
+                        faMeshDecompPtr.reset
+                        (
+                            new faMeshDecomposition
                             (
-                                areaName,
-                                autoPtr<faMeshDecomposition>::New
-                                (
-                                    areaName,
-                                    mesh,
-                                    mesh.nProcs(),
-                                    mesh.model()
-                                )
-                            );
-                        }
+                                mesh,
+                                mesh.nProcs(),
+                                mesh.model()
+                            )
+                        );
                     }
                 }
 
@@ -1094,7 +1066,7 @@ int main(int argc, char *argv[])
 
                     processorDb.setTime(runTime);
 
-                    // Read the mesh
+                    // read the mesh
                     if (!procMeshList.set(proci))
                     {
                         procMeshList.set
@@ -1301,15 +1273,12 @@ int main(int argc, char *argv[])
                 }
 
 
-                // Finite-area mesh and field decomposition
-                for (auto& iter : faMeshDecompHashes.sorted())
+                // Finite area mesh and field decomposition
+                if (faMeshDecompPtr)
                 {
-                    const word& areaName = iter.key();
+                    Info<< "\nFinite area mesh decomposition" << endl;
 
-                    faMeshDecomposition& aMesh = *(iter.val());
-
-                    Info<< "\nFinite area mesh decomposition: "
-                        << areaName << endl;
+                    faMeshDecomposition& aMesh = faMeshDecompPtr();
 
                     aMesh.decomposeMesh();
                     aMesh.writeDecomposition();
@@ -1320,13 +1289,9 @@ int main(int argc, char *argv[])
 
                     faFieldDecomposer::fieldsCache areaFieldCache;
 
-                    if
-                    (
-                        const auto objs = faObjects.cfind(areaName);
-                        doDecompFields && objs.good()
-                    )
+                    if (doDecompFields)
                     {
-                        areaFieldCache.readAllFields(aMesh, objs.val());
+                        areaFieldCache.readAllFields(aMesh, faObjects);
                     }
 
                     const label nAreaFields = areaFieldCache.size();
@@ -1357,7 +1322,7 @@ int main(int argc, char *argv[])
 
                         processorDb.setTime(runTime);
 
-                        // Read the volume mesh
+                        // Read the mesh
                         fvMesh procFvMesh
                         (
                             IOobject
@@ -1368,7 +1333,7 @@ int main(int argc, char *argv[])
                             )
                         );
 
-                        faMesh procMesh(areaName, procFvMesh);
+                        faMesh procMesh(procFvMesh);
 
                         // // Does not work.  HJ, 15/Aug/2017
                         // const labelIOList& faceProcAddressing =
@@ -1427,11 +1392,7 @@ int main(int argc, char *argv[])
                             boundaryProcAddressing
                         );
 
-                        areaFieldCache.decomposeAllFields
-                        (
-                            fieldDecomposer,
-                            args.verbose()  // report
-                        );
+                        areaFieldCache.decomposeAllFields(fieldDecomposer);
                     }
                 }
             }

applications/utilities/parallelProcessing/reconstructPar/reconstructPar.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
-    Copyright (C) 2015-2025 OpenCFD Ltd.
+    Copyright (C) 2015-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -91,7 +91,6 @@ int main(int argc, char *argv[])
     argList::noParallel();
 
     #include "addAllRegionOptions.H"
-    #include "addAllFaRegionOptions.H"
 
     argList::addVerboseOption();
     argList::addOption
@@ -202,17 +201,9 @@ int main(int argc, char *argv[])
 
     const bool newTimes = args.found("newTimes");
 
-    // Handle -allRegions, -regions, -region
+    // Get region names
     #include "getAllRegionOptions.H"
 
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
-
-    if (!doFiniteArea)
-    {
-        areaRegionNames.clear();  // For consistency
-    }
-
     // Determine the processor count
     label nProcs{0};
 
@@ -400,30 +391,19 @@ int main(int argc, char *argv[])
                 IOobjectOption::NO_REGISTER
             );
 
-            // The finite-area fields (multiple finite-area per volume)
-            HashTable<IOobjectList> faObjects;
+            IOobjectList faObjects;
 
             if (doFiniteArea && doFields)
             {
-                // Lists of finite-area fields - scan on processor0
-                faObjects.reserve(areaRegionNames.size());
-
-                for (const word& areaName : areaRegionNames)
-                {
-                    // The finite-area objects for this area region
-                    IOobjectList objs
-                    (
-                        procMeshes.meshes()[0],
-                        databases[0].timeName(),
-                        faMesh::dbDir(areaName),  // local relative to mesh
-                        IOobjectOption::NO_REGISTER
-                    );
-
-                    if (!objs.empty())
-                    {
-                        faObjects.emplace_set(areaName, std::move(objs));
-                    }
-                }
+                // List of area mesh objects (assuming single region)
+                // - scan on processor0
+                faObjects = IOobjectList
+                (
+                    procMeshes.meshes()[0],
+                    databases[0].timeName(),
+                    faMesh::dbDir(word::null),  // local relative to mesh
+                    IOobjectOption::NO_REGISTER
+                );
             }
 
             if (doFields)
@@ -573,60 +553,42 @@ int main(int argc, char *argv[])
             }
 
 
-            // Reconstruct any finite-area fields
-            if (doFiniteArea)
+            // If there are any FA fields, reconstruct them
+
+            if (!doFiniteArea)
             {
-                bool hadFaFields = false;
-                for (const word& areaName : areaRegionNames)
-                {
-                    const auto objs = faObjects.cfind(areaName);
-                    if (!objs.good())
-                    {
-                        continue;
-                    }
-                    const auto& faObjs = objs.val();
-
-                    if
-                    (
-                        !faObjs.count(fieldTypes::is_area)
-                     && !faObjs.count<edgeScalarField>()
-                    )
-                    {
-                        continue;
-                    }
-
-                    hadFaFields = true;
-
-                    Info<< "Reconstructing finite-area fields ["
-                        << polyMesh::regionName(areaName)
-                        << "]" << nl << endl;
-
-                    const faMesh aMesh(areaName, mesh);
-
-                    processorFaMeshes procFaMeshes
-                    (
-                        procMeshes.meshes(),
-                        areaName
-                    );
-
-                    faFieldReconstructor reconstructor
-                    (
-                        aMesh,
-                        procFaMeshes.meshes(),
-                        procFaMeshes.edgeProcAddressing(),
-                        procFaMeshes.faceProcAddressing(),
-                        procFaMeshes.boundaryProcAddressing()
-                    );
-
-                    reconstructor.reconstructAllFields(faObjs);
-                }
-
-                if (!hadFaFields)
-                {
-                    Info << "No finite-area fields" << nl << endl;
-                }
             }
+            else if
+            (
+                faObjects.count<areaScalarField>()
+             || faObjects.count<areaVectorField>()
+             || faObjects.count<areaSphericalTensorField>()
+             || faObjects.count<areaSymmTensorField>()
+             || faObjects.count<areaTensorField>()
+             || faObjects.count<edgeScalarField>()
+            )
+            {
+                Info << "Reconstructing FA fields" << nl << endl;
 
+                faMesh aMesh(mesh);
+
+                processorFaMeshes procFaMeshes(procMeshes.meshes());
+
+                faFieldReconstructor reconstructor
+                (
+                    aMesh,
+                    procFaMeshes.meshes(),
+                    procFaMeshes.edgeProcAddressing(),
+                    procFaMeshes.faceProcAddressing(),
+                    procFaMeshes.boundaryProcAddressing()
+                );
+
+                reconstructor.reconstructAllFields(faObjects);
+            }
+            else
+            {
+                Info << "No FA fields" << nl << endl;
+            }
 
             if (doReconstructSets)
             {

applications/utilities/parallelProcessing/reconstructParMesh/reconstructParMesh.C

@@ -119,10 +119,17 @@ autoPtr<faceCoupleInfo> determineCoupledFaces
         const polyBoundaryMesh& masterPatches = masterMesh.boundaryMesh();
 
 
-        DynamicList<label> masterFaces(masterMesh.nBoundaryFaces());
+        DynamicList<label> masterFaces
+        (
+            masterMesh.nFaces()
+          - masterMesh.nInternalFaces()
+        );
 
-        for (const polyPatch& pp : masterPatches)
+
+        forAll(masterPatches, patchi)
         {
+            const polyPatch& pp = masterPatches[patchi];
+
             if (isA<processorPolyPatch>(pp))
             {
                 for
@@ -132,8 +139,11 @@ autoPtr<faceCoupleInfo> determineCoupledFaces
                     proci++
                 )
                 {
-                    const string toProcString("to" + Foam::name(proci));
-                    if (pp.name().ends_with(toProcString))
+                    const string toProcString("to" + name(proci));
+                    if (
+                        pp.name().rfind(toProcString)
+                     == (pp.name().size()-toProcString.size())
+                    )
                     {
                         label meshFacei = pp.start();
                         forAll(pp, i)
@@ -146,6 +156,7 @@ autoPtr<faceCoupleInfo> determineCoupledFaces
 
             }
         }
+        masterFaces.shrink();
 
 
         // Pick up all patches on meshToAdd ending in "procBoundaryDDDtoYYY"
@@ -153,10 +164,16 @@ autoPtr<faceCoupleInfo> determineCoupledFaces
 
         const polyBoundaryMesh& addPatches = meshToAdd.boundaryMesh();
 
-        DynamicList<label> addFaces(meshToAdd.nBoundaryFaces());
+        DynamicList<label> addFaces
+        (
+            meshToAdd.nFaces()
+          - meshToAdd.nInternalFaces()
+        );
 
-        for (const polyPatch& pp : addPatches)
+        forAll(addPatches, patchi)
         {
+            const polyPatch& pp = addPatches[patchi];
+
             if (isA<processorPolyPatch>(pp))
             {
                 bool isConnected = false;
@@ -198,6 +215,7 @@ autoPtr<faceCoupleInfo> determineCoupledFaces
                 }
             }
         }
+        addFaces.shrink();
 
         return autoPtr<faceCoupleInfo>::New
         (
@@ -484,14 +502,15 @@ void writeMaps
 
     Info<< "    pointProcAddressing" << endl;
     ioAddr.rename("pointProcAddressing");
-    labelIOList::writeContents(ioAddr, pointProcAddressing);
+    IOList<label>::writeContents(ioAddr, pointProcAddressing);
 
     // From processor face to reconstructed mesh face
-    // - add turning index to faceProcAddressing.
-    //   See reconstructPar for meaning of turning index.
-
-    labelList faceProcAddr(faceProcAddressing);
+    Info<< "    faceProcAddressing" << endl;
+    ioAddr.rename("faceProcAddressing");
+    labelIOList faceProcAddr(ioAddr, faceProcAddressing);
 
+    // Now add turning index to faceProcAddressing.
+    // See reconstructPar for meaning of turning index.
     forAll(faceProcAddr, procFacei)
     {
         const label masterFacei = faceProcAddr[procFacei];
@@ -526,21 +545,19 @@ void writeMaps
         }
     }
 
-    Info<< "    faceProcAddressing" << endl;
-    ioAddr.rename("faceProcAddressing");
-    labelIOList::writeContents(ioAddr, faceProcAddr);
-    faceProcAddr.clear();
+    faceProcAddr.write();
+
 
     // From processor cell to reconstructed mesh cell
     Info<< "    cellProcAddressing" << endl;
     ioAddr.rename("cellProcAddressing");
-    labelIOList::writeContents(ioAddr, cellProcAddressing);
+    IOList<label>::writeContents(ioAddr, cellProcAddressing);
 
 
     // From processor patch to reconstructed mesh patch
     Info<< "    boundaryProcAddressing" << endl;
     ioAddr.rename("boundaryProcAddressing");
-    labelIOList::writeContents(ioAddr, boundProcAddressing);
+    IOList<label>::writeContents(ioAddr, boundProcAddressing);
 
     Info<< endl;
 }
@@ -628,8 +645,7 @@ void sortFaEdgeMapping
 {
     // From faMeshReconstructor.C - edge shuffling on patches
 
-    Map<label> remapGlobal;
-    remapGlobal.reserve(onePatch.nEdges());
+    Map<label> remapGlobal(2*onePatch.nEdges());
     for (label edgei = 0; edgei < onePatch.nInternalEdges(); ++edgei)
     {
         remapGlobal.insert(edgei, remapGlobal.size());
@@ -763,11 +779,6 @@ int main(int argc, char *argv[])
     );
 
     #include "addAllRegionOptions.H"
-    #include "addAllFaRegionOptions.H"
-
-    // Prevent volume fields [with regionFaModels] from incidental
-    // triggering finite-area
-    regionModels::allowFaModels(false);
 
     // Prevent volume BCs from triggering finite-area
     regionModels::allowFaModels(false);
@@ -830,17 +841,9 @@ int main(int argc, char *argv[])
         }
     }
 
-    // Handle -allRegions, -regions, -region
+    // Get region names
     #include "getAllRegionOptions.H"
 
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
-
-    if (!doFiniteArea)
-    {
-        areaRegionNames.clear();  // For consistency
-    }
-
     // Determine the processor count
     label nProcs{0};
 
@@ -932,8 +935,7 @@ int main(int argc, char *argv[])
                 polyMesh::meshDir(regionName),
                 databases[0],
                 IOobject::NO_READ,
-                IOobject::NO_WRITE,
-                IOobject::NO_REGISTER
+                IOobject::NO_WRITE
             );
 
             // Problem: faceCompactIOList recognises both 'faceList' and
@@ -1403,12 +1405,8 @@ int main(int argc, char *argv[])
 
 
             // Read finite-area
-            // For each named area region that exists create a HashTable
-            // entry that will contain the PtrList for all processors
-
+            PtrList<faMesh> procFaMeshes(databases.size());
             PtrList<polyMesh> procMeshes(databases.size());
-            HashTable<PtrList<faMesh>> procAreaRegionMeshes;
-            procAreaRegionMeshes.reserve(areaRegionNames.size());
 
             forAll(databases, proci)
             {
@@ -1416,16 +1414,20 @@ int main(int argc, char *argv[])
                     << "Read processor mesh: "
                     << (databases[proci].caseName()/regionDir) << endl;
 
-                const polyMesh& procMesh = procMeshes.emplace
+                procMeshes.set
                 (
                     proci,
-                    IOobject
+                    new polyMesh
                     (
-                        regionName,
-                        databases[proci].timeName(),
-                        databases[proci]
+                        IOobject
+                        (
+                            regionName,
+                            databases[proci].timeName(),
+                            databases[proci]
+                        )
                     )
                 );
+                const polyMesh& procMesh = procMeshes[proci];
 
                 writeMaps
                 (
@@ -1448,67 +1450,38 @@ int main(int argc, char *argv[])
                             "boundary"
                         );
 
-                    for (const word& areaName : areaRegionNames)
+                    IOobject io
+                    (
+                        "faBoundary",
+                        boundaryInst,
+                        faMesh::meshDir(procMesh, word::null),
+                        procMesh.time(),
+                        IOobject::READ_IF_PRESENT,
+                        IOobject::NO_WRITE,
+                        IOobject::NO_REGISTER
+                    );
+
+                    if (io.typeHeaderOk<faBoundaryMesh>(true))
                     {
-                        IOobject io
-                        (
-                            "faBoundary",
-                            boundaryInst,
-                            faMesh::meshDir(procMesh, areaName),
-                            procMesh.time(),
-                            IOobject::READ_IF_PRESENT,
-                            IOobject::NO_WRITE,
-                            IOobject::NO_REGISTER
-                        );
-
-                        if (io.typeHeaderOk<faBoundaryMesh>(true))
-                        {
-                            // Always based on the volume decomposition!
-                            auto& procFaMeshes = procAreaRegionMeshes(areaName);
-                            procFaMeshes.resize(databases.size());
-
-                            procFaMeshes.set
-                            (
-                                proci,
-                                new faMesh(areaName, procMesh)
-                            );
-                        }
+                        // Always based on the volume decomposition!
+                        procFaMeshes.set(proci, new faMesh(procMesh));
                     }
                 }
             }
 
 
-            // A finite-area mapping exists if procFaMeshes was filled
-
-            // Re-read reconstructed polyMesh. Note: could probably be avoided
-            // by merging into loops above.
-            refPtr<polyMesh> masterPolyMeshPtr;
-
-            if (!procAreaRegionMeshes.empty())
+            // Finite-area mapping
+            doFiniteArea = false;
+            forAll(procFaMeshes, proci)
             {
-                masterPolyMeshPtr.reset
-                (
-                    new polyMesh
-                    (
-                        IOobject
-                        (
-                            regionName,
-                            runTime.timeName(),
-                            runTime
-                        ),
-                        true
-                    )
-                );
+                if (procFaMeshes.set(proci))
+                {
+                    doFiniteArea = true;
+                }
             }
 
-            // Process any finite-area meshes
-            for (const auto& iter : procAreaRegionMeshes.csorted())
+            if (doFiniteArea)
             {
-                const auto& areaName = iter.key();
-                const auto& procFaMeshes = iter.val();
-
-                const polyMesh& masterMesh = masterPolyMeshPtr();
-
                 // Addressing from processor to reconstructed case
                 labelListList faFaceProcAddressing(nProcs);
                 labelListList faEdgeProcAddressing(nProcs);
@@ -1526,10 +1499,32 @@ int main(int argc, char *argv[])
 
                     faBoundProcAddressing[proci] = identity(bm.size());
                     // Mark processor patches
-                    faBoundProcAddressing[proci].slice(bm.nNonProcessor()) = -1;
+                    for
+                    (
+                        label patchi = bm.nNonProcessor();
+                        patchi < bm.size();
+                        ++patchi
+                    )
+                    {
+                        faBoundProcAddressing[proci][patchi] = -1;
+                    }
                 }
 
 
+                // Re-read reconstructed polyMesh. Note: could probably be avoided
+                // by merging into loops above.
+                const polyMesh masterMesh
+                (
+                    IOobject
+                    (
+                        regionName,
+                        runTime.timeName(),
+                        runTime
+                    ),
+                    true
+                );
+
+
                 // faceProcAddressing
                 // ~~~~~~~~~~~~~~~~~~
 
@@ -1564,13 +1559,13 @@ int main(int argc, char *argv[])
                 // Construct without patches
                 faMesh masterFaMesh
                 (
-                    areaName,
                     masterMesh,
                     std::move(masterFaceLabels),
                     io
                 );
 
-                const auto& masterPatch = masterFaMesh.patch();
+                const uindirectPrimitivePatch& masterPatch =
+                    masterFaMesh.patch();
 
 
                 // pointProcAddressing
@@ -1582,7 +1577,7 @@ int main(int argc, char *argv[])
                     const auto& procPatch = procFaMeshes[proci].patch();
                     const auto& mp = procPatch.meshPoints();
 
-                    auto& pointAddr = faPointProcAddressing[proci];
+                    labelList& pointAddr = faPointProcAddressing[proci];
                     pointAddr.resize_nocopy(mp.size());
 
                     forAll(mp, i)
@@ -1631,7 +1626,8 @@ int main(int argc, char *argv[])
                 label nPatches = 0;
                 forAll(completePatches, patchi)
                 {
-                    const auto& patchEdgeLabels = singlePatchEdgeLabels[patchi];
+                    const labelList& patchEdgeLabels =
+                        singlePatchEdgeLabels[patchi];
 
                     const faPatch& fap = procMesh0.boundary()[patchi];
 
@@ -1662,11 +1658,11 @@ int main(int argc, char *argv[])
 
                 // Serial mesh - no parallel communication
 
-                const bool oldParRun = UPstream::parRun(false);
+                const bool oldParRun = Pstream::parRun(false);
 
                 masterFaMesh.addFaPatches(completePatches);
 
-                UPstream::parRun(oldParRun);  // Restore parallel state
+                Pstream::parRun(oldParRun);  // Restore parallel state
 
 
                 // Write mesh & individual addressing

applications/utilities/parallelProcessing/redistributePar/loadOrCreateMesh.C

@@ -33,266 +33,99 @@ License
 #include "decomposedBlockData.H"
 #include "IFstream.H"
 
-// * * * * * * * * * * * * * * * Local Functions * * * * * * * * * * * * * * //
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
 
-// Trimmed-down version of lookupAndCacheProcessorsPath
-// with Foam::exists() check. No caching.
-
-// Check for two conditions:
-// - file has to exist
-// - if collated the entry has to exist inside the file
-
-// Note: bypass fileOperation::filePath(IOobject&) since has problems
-//       with going to a different number of processors
-//       (in collated format). Use file-based searching instead
-
-namespace Foam
+bool Foam::checkFileExistence(const fileName& fName)
 {
+    // Trimmed-down version of lookupAndCacheProcessorsPath
+    // with Foam::exists() check. No caching.
 
-// If indeed collated format:
-// Collect block-number in individual filenames
-// (might differ on different processors)
-static bool checkFileExistenceCollated
-(
-    const Foam::fileOperation& handler,
-    const Foam::fileName& fName
-)
-{
-    // using namespace Foam;
+    // Check for two conditions:
+    // - file has to exist
+    // - if collated the entry has to exist inside the file
+
+    // Note: bypass fileOperation::filePath(IOobject&) since has problems
+    //       with going to a different number of processors
+    //       (in collated format). Use file-based searching instead
+
+    const auto& handler = Foam::fileHandler();
+    typedef fileOperation::procRangeType procRangeType;
+
+    fileName path, pDir, local;
+    procRangeType group;
+    label numProcs;
+    const label proci =
+        fileOperation::splitProcessorPath
+        (fName, path, pDir, local, group, numProcs);
 
     bool found = false;
+
+    if (proci != -1)
     {
-        const label handlerComm = handler.comm();
+        // Read all directories to see any beginning with processor
+        // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-        const label globalProci = UPstream::myProcNo(UPstream::worldComm);
-        const label handlerProci = UPstream::myProcNo(handlerComm);
-        const label nHandlerProcs = UPstream::nProcs(handlerComm);
-
-        // Determine my local block number
-        label myBlockNumber = -1;
-        {
-            fileOperation::procRangeType group;
-            label proci = fileOperation::detectProcessorPath(fName, group);
-
-            if (proci == -1 && group.empty())
-            {
-                // 'processorsXXX' format so contains all ranks
-                // according to worldComm
-                myBlockNumber = globalProci;
-            }
-            else
-            {
-                // 'processorsXXX_n-m' format so check for relative rank
-                myBlockNumber = handlerProci;
-            }
-        }
-
-        // Since we are streaming anyhow, could also pack as tuple:
-        // Tuple2<fileName, label>
-
-
-        // Collect file names on master of local communicator
-        const fileNameList fNames
+        const fileNameList dirEntries
         (
-            Pstream::listGatherValues
-            (
-                fName,
-                handlerComm,
-                UPstream::msgType()
-            )
+            handler.readDir(path, fileName::Type::DIRECTORY)
         );
 
-        // Collect block numbers on master of local communicator
-        const labelList myBlockNumbers
-        (
-            Pstream::listGatherValues
-            (
-                myBlockNumber,
-                handlerComm,
-                UPstream::msgType()
-            )
-        );
+        // Extract info from processorN or processorsNN
+        // - highest processor number
+        // - directory+offset containing data for proci
 
-        // Determine for all whether the filename exists in the collated file.
-        boolList allFound;
-
-        if (UPstream::master(handlerComm))
+        // label nProcs = 0;
+        for (const fileName& dirN : dirEntries)
         {
-            allFound.resize(nHandlerProcs, false);
+            // Analyse directory name
+            label rNum(-1);
+            const label readProci =
+                fileOperation::detectProcessorPath(dirN, group, &rNum);
 
-            // Store nBlocks and index of file that was used for nBlocks
-            label nBlocks = -1;
-            label blockRanki = -1;
-            forAll(fNames, ranki)
+            if (proci == readProci)
             {
-                if
-                (
-                    blockRanki == -1
-                 || (fNames[ranki] != fNames[blockRanki])
-                )
+                // Found "processorN"
+                if (Foam::exists(path/dirN/local))
                 {
-                    blockRanki = ranki;
-                    IFstream is(fNames[ranki]);
-                    nBlocks = decomposedBlockData::getNumBlocks(is);
+                    found = true;
+                    break;
                 }
+            }
+            else if (rNum != -1)
+            {
+                // "processorsNN" or "processorsNN_start-end"
+                if (group.empty())
+                {
+                    // "processorsNN"
+                    if (proci < rNum && Foam::exists(path/dirN/local))
+                    {
+                        found = true;
+                        break;
+                    }
+                }
+                else if (group.contains(proci))
+                {
+                    // "processorsNN_start-end"
+                    // - save the local proc offset
 
-                allFound[ranki] = (myBlockNumbers[ranki] < nBlocks);
+                    if (Foam::exists(path/dirN/local))
+                    {
+                        found = true;
+                        break;
+                    }
+                }
             }
         }
+    }
 
-        // Scatter using the handler communicator
-        found = Pstream::listScatterValues
-        (
-            allFound,
-            handlerComm,
-            UPstream::msgType()
-        );
+    if (!found)
+    {
+        found = Foam::exists(fName);
     }
 
     return found;
 }
 
-} // End namespace
-
-
-// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
-
-Foam::bitSet Foam::haveProcessorFile
-(
-    const word& name,           // eg "faces"
-    const fileName& instance,   // eg "constant"
-    const fileName& local,      // eg, polyMesh
-    const Time& runTime,
-    const bool verbose
-)
-{
-    const auto& handler = Foam::fileHandler();
-
-    const fileName fName
-    (
-        handler.filePath(runTime.path()/instance/local/name)
-    );
-
-    bool found = handler.isFile(fName);
-
-    // Assume non-collated (as fallback value).
-    // If everyone claims to have the file, use master to verify if
-    // collated is involved.
-
-    bool isCollated = false;
-
-    if (returnReduceAnd(found, UPstream::worldComm))
-    {
-        // Test for collated format.
-        // Note: can test only world-master. Since even host-collated will have
-        // same file format type for all processors
-        if (UPstream::master(UPstream::worldComm))
-        {
-            const bool oldParRun = UPstream::parRun(false);
-
-            if (IFstream is(fName); is.good())
-            {
-                IOobject io(name, instance, local, runTime);
-                io.readHeader(is);
-
-                isCollated = decomposedBlockData::isCollatedType(io);
-            }
-
-            UPstream::parRun(oldParRun);
-        }
-        Pstream::broadcast(isCollated, UPstream::worldComm);
-    }
-
-    // For collated, check that the corresponding blocks exist
-    if (isCollated)
-    {
-        found = checkFileExistenceCollated(handler, fName);
-    }
-
-
-    // Globally consistent information about who has the file
-    bitSet haveFileOnProc = bitSet::allGather(found, UPstream::worldComm);
-
-    if (verbose)
-    {
-        Info<< "Per processor availability of \""
-            << name << "\" file in " << instance/local << nl
-            << "    " << flatOutput(haveFileOnProc) << nl << endl;
-    }
-
-    return haveFileOnProc;
-}
-
-
-Foam::boolList Foam::haveMeshFile
-(
-    const word& name,           // eg "faces"
-    const fileName& instance,   // eg "constant"
-    const fileName& local,      // eg, polyMesh
-    const Time& runTime,
-    const bool verbose
-)
-{
-    const auto& handler = Foam::fileHandler();
-
-    const fileName fName
-    (
-        handler.filePath(runTime.path()/instance/local/name)
-    );
-
-    bool found = handler.isFile(fName);
-
-    // Assume non-collated (as fallback value).
-    // If everyone claims to have the file, use master to verify if
-    // collated is involved.
-
-    bool isCollated = false;
-
-    if (returnReduceAnd(found, UPstream::worldComm))
-    {
-        // Test for collated format.
-        // Note: can test only world-master. Since even host-collated will have
-        // same file format type for all processors
-        if (UPstream::master(UPstream::worldComm))
-        {
-            const bool oldParRun = UPstream::parRun(false);
-
-            if (IFstream is(fName); is.good())
-            {
-                IOobject io(name, instance, local, runTime);
-                io.readHeader(is);
-
-                isCollated = decomposedBlockData::isCollatedType(io);
-            }
-
-            UPstream::parRun(oldParRun);
-        }
-        Pstream::broadcast(isCollated, UPstream::worldComm);
-    }
-
-    // For collated, check that the corresponding blocks exist
-    if (isCollated)
-    {
-        found = checkFileExistenceCollated(handler, fName);
-    }
-
-
-    // Globally consistent information about who has a mesh
-    boolList haveFileOnProc
-    (
-        UPstream::allGatherValues<bool>(found, UPstream::worldComm)
-    );
-
-    if (verbose)
-    {
-        Info<< "Per processor availability of \""
-            << name << "\" file in " << instance/local << nl
-            << "    " << flatOutput(haveFileOnProc) << nl << endl;
-    }
-
-    return haveFileOnProc;
-}
-
 
 Foam::boolList Foam::haveMeshFile
 (
@@ -302,49 +135,143 @@ Foam::boolList Foam::haveMeshFile
     const bool verbose
 )
 {
+    #if 0
+
+    // Simple directory scanning - too fragile
+    bool found = checkFileExistence(runTime.path()/meshPath/meshFile);
+
+    #else
+
+    // Trimmed-down version of lookupAndCacheProcessorsPath
+    // with Foam::exists() check. No caching.
+
+    // Check for two conditions:
+    // - file has to exist
+    // - if collated the entry has to exist inside the file
+
+    // Note: bypass fileOperation::filePath(IOobject&) since has problems
+    //       with going to a different number of processors
+    //       (in collated format). Use file-based searching instead
+
     const auto& handler = Foam::fileHandler();
+    typedef fileOperation::procRangeType procRangeType;
 
     const fileName fName
     (
         handler.filePath(runTime.path()/meshPath/meshFile)
     );
-
     bool found = handler.isFile(fName);
-
-    // Assume non-collated (as fallback value).
-    // If everyone claims to have the file, use master to verify if
-    // collated is involved.
-
-    bool isCollated = false;
-
-    if (returnReduceAnd(found, UPstream::worldComm))
+    if (returnReduceAnd(found)) // worldComm
     {
-        // Test for collated format.
+        // Bit tricky: avoid having all slaves open file since this involves
+        // reading it on master and broadcasting it. This fails if file > 2G.
+        // So instead only read on master
+
+        bool isCollated = false;
+
         // Note: can test only world-master. Since even host-collated will have
         // same file format type for all processors
         if (UPstream::master(UPstream::worldComm))
         {
             const bool oldParRun = UPstream::parRun(false);
 
-            if (IFstream is(fName); is.good())
+            IFstream is(fName);
+            if (is.good())
             {
                 IOobject io(meshFile, meshPath, runTime);
                 io.readHeader(is);
 
                 isCollated = decomposedBlockData::isCollatedType(io);
             }
-
             UPstream::parRun(oldParRun);
         }
-        Pstream::broadcast(isCollated, UPstream::worldComm);
-    }
+        Pstream::broadcast(isCollated); //UPstream::worldComm
 
-    // For collated, check that the corresponding blocks exist
-    if (isCollated)
-    {
-        found = checkFileExistenceCollated(handler, fName);
-    }
 
+        // Collect block-number in individual filenames (might differ
+        // on different processors)
+        if (isCollated)
+        {
+            const label nProcs = UPstream::nProcs(fileHandler().comm());
+            const label myProcNo = UPstream::myProcNo(fileHandler().comm());
+
+            // Collect file names on master of local communicator
+            const fileNameList fNames
+            (
+                Pstream::listGatherValues
+                (
+                    fName,
+                    fileHandler().comm(),
+                    UPstream::msgType()
+                )
+            );
+
+            // Collect local block number
+            label myBlockNumber = -1;
+            {
+                procRangeType group;
+                label proci = fileOperation::detectProcessorPath(fName, group);
+
+                if (proci == -1 && group.empty())
+                {
+                    // 'processorsXXX' format so contains all ranks
+                    // according to worldComm
+                    myBlockNumber = UPstream::myProcNo(UPstream::worldComm);
+                }
+                else
+                {
+                    // 'processorsXXX_n-m' format so check for the
+                    // relative rank
+                    myBlockNumber = myProcNo;
+                }
+            }
+            const labelList myBlockNumbers
+            (
+                Pstream::listGatherValues
+                (
+                    myBlockNumber,
+                    fileHandler().comm(),
+                    UPstream::msgType()
+                )
+            );
+
+
+
+            // Determine for all whether the filename exists in the collated
+            // file.
+            boolList allFound(nProcs, false);
+
+            if (UPstream::master(fileHandler().comm()))
+            {
+                // Store nBlocks and index of file that was used for nBlocks
+                label nBlocks = -1;
+                label blockRanki = -1;
+                forAll(fNames, ranki)
+                {
+                    if
+                    (
+                        blockRanki == -1
+                     || (fNames[ranki] != fNames[blockRanki])
+                    )
+                    {
+                        blockRanki = ranki;
+                        IFstream is(fNames[ranki]);
+                        nBlocks = decomposedBlockData::getNumBlocks(is);
+                    }
+
+                    allFound[ranki] = (myBlockNumbers[ranki] < nBlocks);
+                }
+            }
+
+            found = Pstream::listScatterValues
+            (
+                allFound,
+                fileHandler().comm(),
+                UPstream::msgType()
+            );
+        }
+    }
+    #endif
 
     // Globally consistent information about who has a mesh
     boolList haveFileOnProc

applications/utilities/parallelProcessing/redistributePar/loadOrCreateMesh.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2012 OpenFOAM Foundation
-    Copyright (C) 2022-2025 OpenCFD Ltd.
+    Copyright (C) 2022-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -48,32 +48,15 @@ namespace Foam
 // Forward Declarations
 class faMesh;
 
-//- Check for availability of specified file (on all ranks)
-bitSet haveProcessorFile
-(
-    const word& name,           // eg, "faces"
-    const fileName& instance,   // eg, "constant"
-    const fileName& local,      // eg, "polyMesh"
-    const Time& runTime,
-    const bool verbose = true
-);
+//- Check for availability of given file
+bool checkFileExistence(const fileName& fName);
 
-//- Check for availability of specified file (on all ranks)
-boolList haveMeshFile
-(
-    const word& name,           // eg, "faces"
-    const fileName& instance,   // eg, "constant"
-    const fileName& local,      // eg, "polyMesh"
-    const Time& runTime,
-    const bool verbose = true
-);
-
-//- Check for availability of specified mesh file
+//- Check for availability of specified mesh file (default: "faces")
 boolList haveMeshFile
 (
     const Time& runTime,
     const fileName& meshPath,
-    const word& meshFile,
+    const word& meshFile = "faces",
     const bool verbose = true
 );
 
@@ -92,7 +75,7 @@ void masterMeshInstance
     fileName& pointsInstance
 );
 
-} // End namespace Foam
+}
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/utilities/postProcessing/dataConversion/foamToEnsight/checkFieldAvailability.H

@@ -21,59 +21,44 @@ Requires
 
 // Initially all possible objects that are available at the final time
 List<wordHashSet> availableRegionObjectNames(meshes.size());
-List<HashTable<wordHashSet>> availableFaRegionObjectNames(meshes.size());
+List<wordHashSet> availableFaRegionObjectNames(meshes.size());
 
 forAll(meshes, regioni)
 {
     const auto& mesh = meshes[regioni];
 
     IOobjectList objects;
-    HashTable<IOobjectList> faObjects;
+    IOobjectList faObjects;
 
     if (doConvertFields && !timeDirs.empty())
     {
-        // const word& checkTimeDir = timeDirs.back().name();
-
         // List of volume mesh objects for this instance
         objects = IOobjectList(mesh, timeDirs.back().name());
 
+        // List of area mesh objects (assuming single region)
+        faObjects = IOobjectList
+        (
+            mesh.time(),
+            timeDirs.back().name(),
+            faMesh::dbDir(mesh, word::null),
+            IOobjectOption::NO_REGISTER
+        );
+
         if (fieldSelector)
         {
             objects.filterObjects(fieldSelector);
+            faObjects.filterObjects(fieldSelector);
         }
 
         // Remove "*_0" restart fields
         objects.prune_0();
+        faObjects.prune_0();
 
         if (!doPointValues)
         {
             // Prune point fields if disabled
             objects.filterClasses(Foam::fieldTypes::is_point, true);
         }
-
-
-        // The finite-area regions and their fields for this volume region
-        // and instance
-        faObjects.reserve(areaRegionNames.size());
-        for (const word& areaName : areaRegionNames)
-        {
-            IOobjectList objs
-            (
-                faMesh::Registry(mesh),
-                timeDirs.back().name(),
-                polyMesh::regionName(areaName),
-                IOobjectOption::NO_REGISTER
-            );
-
-            if (fieldSelector)
-            {
-                objs.filterObjects(fieldSelector);
-            }
-
-            // Remove "*_0" restart fields
-            objs.prune_0();
-            faObjects(areaName) = std::move(objs);
-        }
     }
 
     // Volume fields
@@ -93,29 +78,20 @@ forAll(meshes, regioni)
     }
 
     // Area fields
-    for (const word& areaName : areaRegionNames)
+    if (!faObjects.empty())
     {
-        wordList objectNames;
+        wordList objectNames(faObjects.sortedNames());
 
-        if (const auto iter = faObjects.cfind(areaName); iter.good())
-        {
-            objectNames = iter.val().sortedNames();
-
-            // Check availability for all times...
-            checkData
-            (
-                faMesh::Registry(mesh),
-                timeDirs,
-                objectNames,
-                polyMesh::regionName(areaName)
-            );
-        }
-
-        availableFaRegionObjectNames[regioni].emplace_set
+        // Check availability for all times... (assuming single region)
+        checkData
         (
-            areaName,
-            std::move(objectNames)
+            mesh.time(),
+            timeDirs,
+            objectNames,
+            faMesh::dbDir(mesh, word::null)
         );
+
+        availableFaRegionObjectNames[regioni] = objectNames;
     }
 }
 

applications/utilities/postProcessing/dataConversion/foamToEnsight/createMeshAccounting.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2021-2025 OpenCFD Ltd.
+    Copyright (C) 2021-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -15,14 +15,12 @@ Description
 
 \*---------------------------------------------------------------------------*/
 
-// Cases and meshes per volume region
 PtrList<ensightCase> ensightCases(regionNames.size());
 PtrList<ensightMesh> ensightMeshes(regionNames.size());
 
-// Per volume region can have multiple finite-area regions
-List<PtrDynList<faMesh>> meshesFa(regionNames.size());
-List<PtrDynList<ensightCase>> ensightCasesFa(regionNames.size());
-List<PtrDynList<ensightFaMesh>> ensightMeshesFa(regionNames.size());
+PtrList<faMesh> meshesFa(regionNames.size());
+PtrList<ensightCase> ensightCasesFa(regionNames.size());
+PtrList<ensightFaMesh> ensightMeshesFa(regionNames.size());
 
 {
     forAll(regionNames, regioni)
@@ -47,7 +45,6 @@ List<PtrDynList<ensightFaMesh>> ensightMeshesFa(regionNames.size());
             }
         }
 
-        // Volume mesh
         ensightMeshes.set
         (
             regioni,
@@ -62,59 +59,32 @@ List<PtrDynList<ensightFaMesh>> ensightMeshesFa(regionNames.size());
             new ensightCase(ensCasePath, ensCaseName, caseOpts)
         );
 
-        if (!doFiniteArea)
+        if (doFiniteArea)
         {
-            continue;
-        }
-
-        // Note: not every volume region is guaranteed to have
-        // any or all area region(s)
-
-        meshesFa[regioni].reserve_exact(areaRegionNames.size());
-
-        for (const word& areaName : areaRegionNames)
-        {
-            auto faMeshPtr = faMesh::TryNew(areaName, mesh);
+            autoPtr<faMesh> faMeshPtr(faMesh::TryNew(mesh));
 
             if (faMeshPtr)
             {
-                meshesFa[regioni].push_back(std::move(faMeshPtr));
-            }
-        }
-
-        // Setup the ensight components
-        const label nAreas = meshesFa[regioni].size();
-        ensightCasesFa[regioni].reserve_exact(nAreas);
-        ensightMeshesFa[regioni].reserve_exact(nAreas);
-
-        for (const faMesh& areaMesh : meshesFa[regioni])
-        {
-            // Use regionName() - automatically filters for defaultRegion
-            const word& areaName = areaMesh.regionName();
-
-            if (areaName.empty())
-            {
-                // single-region
-                ensightCasesFa[regioni].emplace_back
+                ensightCasesFa.set
                 (
-                    ensCasePath/"finite-area",
-                    "finite-area",
-                    caseOpts
+                    regioni,
+                    new ensightCase
+                    (
+                        ensCasePath/"finite-area",
+                        "finite-area",
+                        caseOpts
+                    )
                 );
-            }
-            else
-            {
-                // multi-region
-                ensightCasesFa[regioni].emplace_back
-                (
-                    ensCasePath/"finite-area"/areaName,
-                    areaName,
-                    caseOpts
-                );
-            }
 
-            auto& ensFaMesh = ensightMeshesFa[regioni].emplace_back(areaMesh);
-            ensFaMesh.verbose(optVerbose);
+                meshesFa.set(regioni, std::move(faMeshPtr));
+
+                ensightMeshesFa.set
+                (
+                    regioni,
+                    new ensightFaMesh(meshesFa[regioni])
+                );
+                ensightMeshesFa[regioni].verbose(optVerbose);
+            }
         }
     }
 }

applications/utilities/postProcessing/dataConversion/foamToEnsight/foamToEnsight.C

@@ -124,7 +124,6 @@ Usage
 #include "OFstream.H"
 #include "Pstream.H"
 #include "HashOps.H"
-#include "PtrDynList.H"
 #include "regionProperties.H"
 
 #include "fvc.H"
@@ -173,7 +172,6 @@ int main(int argc, char *argv[])
     argList::addVerboseOption();
 
     #include "addAllRegionOptions.H"
-    #include "addAllFaRegionOptions.H"
 
     argList::addBoolOption
     (
@@ -441,14 +439,6 @@ int main(int argc, char *argv[])
     // Handle -allRegions, -regions, -region
     #include "getAllRegionOptions.H"
 
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
-
-    if (!doFiniteArea)
-    {
-        areaRegionNames.clear();  // For consistency
-    }
-
     // ------------------------------------------------------------------------
     // Directory management
 
@@ -528,32 +518,29 @@ int main(int argc, char *argv[])
             polyMesh::readUpdateState meshState = mesh.readUpdate();
             const bool moving = (meshState != polyMesh::UNCHANGED);
 
-            // Ensight (fvMesh)
+            // Ensight
             auto& ensCase = ensightCases[regioni];
             auto& ensMesh = ensightMeshes[regioni];
 
+            // Finite-area (can be missing)
+            auto* ensFaCasePtr = ensightCasesFa.get(regioni);
+            auto* ensFaMeshPtr = ensightMeshesFa.get(regioni);
+
             ensCase.setTime(timeDirs[timei], timeIndex);
-
-            // Finite-area (optional)
-            // Accounting exists for each volume region but may be empty
-            auto& ensFaCases = ensightCasesFa[regioni];
-            auto& ensFaMeshes = ensightMeshesFa[regioni];
-
-            for (auto& ensFaCase : ensFaCases)
+            if (ensFaCasePtr)
             {
-                ensFaCase.setTime(timeDirs[timei], timeIndex);
+                ensFaCasePtr->setTime(timeDirs[timei], timeIndex);
             }
 
-            // Movement
             if (moving)
             {
                 ensMesh.expire();
                 ensMesh.correct();
 
-                for (auto& ensFaMesh : ensFaMeshes)
+                if (ensFaMeshPtr)
                 {
-                    ensFaMesh.expire();
-                    ensFaMesh.correct();
+                    ensFaMeshPtr->expire();
+                    ensFaMeshPtr->correct();
                 }
             }
 
@@ -568,19 +555,15 @@ int main(int argc, char *argv[])
                 }
 
                 // finite-area
-                forAll(ensFaMeshes, areai)
+                if (ensFaCasePtr && ensFaMeshPtr)
                 {
-                    const auto& ensFaCase = ensFaCases[areai];
-                    const auto& ensFaMesh = ensFaMeshes[areai];
-
                     autoPtr<ensightGeoFile> os =
-                        ensFaCase.newGeometry(hasMovingMesh);
+                        ensFaCasePtr->newGeometry(hasMovingMesh);
 
-                    ensFaMesh.write(os.ref());
+                    ensFaMeshPtr->write(os.ref());
                 }
             }
 
-
             // Objects at this time
             IOobjectList objects(mesh, runTime.timeName());
 
@@ -592,37 +575,23 @@ int main(int argc, char *argv[])
             // Volume, internal, point fields
             #include "convertVolumeFields.H"
 
-            // finite-area
-            forAll(ensFaMeshes, areai)
+            // The finite-area objects at this time
+            IOobjectList faObjects;
+
+            if (ensFaMeshPtr)
             {
-                auto* ensFaCasePtr = ensFaCases.get(areai);
-                auto* ensFaMeshPtr = ensFaMeshes.get(areai);
+                faObjects =
+                    IOobjectList(ensFaMeshPtr->mesh(), runTime.timeName());
 
-                // The finite-area region objects at this time
-                IOobjectList faObjects;
-
-                if (ensFaMeshPtr)
-                {
-                    const word& areaName = ensFaMeshPtr->mesh().name();
-
-                    faObjects = IOobjectList
-                    (
-                        faMesh::Registry(mesh),
-                        runTime.timeName(),
-                        polyMesh::regionName(areaName),
-                        IOobjectOption::NO_REGISTER
-                    );
-
-                    faObjects.filterObjects
-                    (
-                        availableFaRegionObjectNames[regioni](areaName)
-                    );
-                }
-
-                // The finiteArea fields
-                #include "convertAreaFields.H"
+                faObjects.filterObjects
+                (
+                    availableFaRegionObjectNames[regioni]
+                );
             }
 
+            // The finiteArea fields
+            #include "convertAreaFields.H"
+
             // Lagrangian fields
             #include "convertLagrangian.H"
         }
@@ -635,13 +604,14 @@ int main(int argc, char *argv[])
     // Write cases
     forAll(ensightCases, regioni)
     {
-        // finite-volume
         ensightCases[regioni].write();
+    }
 
-        // Finite-area (if any)
-        for (const auto& ensFaCase : ensightCasesFa[regioni])
+    forAll(ensightCasesFa, regioni)
+    {
+        if (ensightCasesFa.set(regioni))
         {
-            ensFaCase.write();
+            ensightCasesFa[regioni].write();
         }
     }
 

applications/utilities/postProcessing/dataConversion/foamToEnsight/readFields.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2018-2025 OpenCFD Ltd.
+    Copyright (C) 2018-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -26,6 +26,7 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "readFields.H"
+#include "volFields.H"
 
 // * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
 
@@ -41,30 +42,26 @@ Foam::label Foam::checkData
 
     wordHashSet goodFields;
 
-    IOobject io
-    (
-        "any-name",   // placeholder
-        "constant",   // placeholder
-        local,
-        obr,
-        IOobjectOption::NO_READ,
-        IOobjectOption::NO_WRITE,
-        IOobjectOption::NO_REGISTER
-    );
-
     for (const word& fieldName : objectNames)
     {
-        // In case prune_0() not previously used...
-        if (fieldName.ends_with("_0")) continue;
+        // // If prune_0() not previously used...
+        // if (objectNames.ends_with("_0")) continue;
 
         bool good = false;
 
         for (const instant& inst : timeDirs)
         {
-            io.resetHeader(fieldName);
-            io.instance() = inst.name();
-
-            good = io.typeHeaderOk<regIOobject>(false, false);
+            good =
+                IOobject
+                (
+                    fieldName,
+                    inst.name(),
+                    local,
+                    obr,
+                    IOobject::NO_READ,
+                    IOobject::NO_WRITE,
+                    IOobject::NO_REGISTER
+                ).typeHeaderOk<volScalarField>(false, false);
 
             if (!good)
             {

applications/utilities/postProcessing/dataConversion/foamToVTK/convertAreaFields.H

@@ -22,66 +22,24 @@ Description
 //
 
 // No subsetting!
-if (doFiniteArea && !areaRegionNames.empty())
+if (doFiniteArea)
 {
     using reportFields = foamToVtkReportFields;
 
-    // The (region) polyMesh being used. No subsetting possible
-    const auto& basePolyMesh = meshProxy.baseMesh();
+    autoPtr<faMesh> faMeshPtr;
 
-    for (const word& areaName : areaRegionNames)
+    const label nAreaFields = faObjects.count(Foam::fieldTypes::is_area);
+
+    if (nAreaFields || withMeshIds)
     {
-        const bool isDefaultRegion(polyMesh::regionName(areaName).empty());
+        faMeshPtr = faMesh::TryNew(meshProxy.baseMesh());
+    }
 
-        // CAUTION
-        // If we want to have constant access to the HashTable:
-        //
-        // (SEGFAULT)
-        // const auto& faObjs = faObjects.lookup(areaName, IOobjectList());
-        //
-        // Use an empty fallback to avoid binding to a temporary:
-        //
-        // const IOobjectList emptyObjectList;
-        // const auto& faObjs = faObjects.lookup(areaName, emptyObjectList);
+    if (faMeshPtr && (nAreaFields || withMeshIds))
+    {
+        const faMesh& areaMesh = faMeshPtr();
 
-        // Since we do not need the area fields afterwards,
-        // just move them out from the HashTable
-
-        IOobjectList faObjs;
-        if (auto iter = faObjects.find(areaName); iter.good())
-        {
-            faObjs = std::move(iter.val());
-        }
-
-        const label nAreaFields = faObjs.count(Foam::fieldTypes::is_area);
-
-        autoPtr<faMesh> faMeshPtr;
-
-        if (nAreaFields || withMeshIds)
-        {
-            faMeshPtr = faMesh::TryNew(areaName, basePolyMesh);
-        }
-
-        if (!faMeshPtr)
-        {
-            if (!isDefaultRegion)
-            {
-                // Report any area region specified but missing
-                // - silently ignore region0
-                Info<< "No area-mesh [" << polyMesh::regionName(areaName)
-                    << "] on volume-region ["
-                    << basePolyMesh.regionName() << "]" << endl;
-            }
-            continue;
-        }
-        const auto& areaMesh = faMeshPtr();
-
-        Info<< "Using area-mesh [" << polyMesh::regionName(areaName)
-            << "] on volume-region ["
-            << basePolyMesh.regionName() << "]" << endl;
-
-
-        reportFields::area(Info, faObjs);
+        reportFields::area(Info, faObjects);
 
         const auto& pp = faMeshPtr->patch();
 
@@ -91,12 +49,7 @@ if (doFiniteArea && !areaRegionNames.empty())
             writeOpts,
             (
                 outputDir/regionDir/"finite-area"
-              / (
-                   isDefaultRegion
-                 ? fileName("finiteArea")
-                 : fileName(areaName/areaName)
-                )
-              + timeDesc
+              / "finiteArea" + timeDesc
             ),
             UPstream::parRun()
         );
@@ -143,7 +96,7 @@ if (doFiniteArea && !areaRegionNames.empty())
         (
             writer,
             areaMesh,
-            faObjs,
+            faObjects,
             true // syncPar
         );
 

applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK.C

@@ -135,13 +135,13 @@ Note
 #include "emptyPolyPatch.H"
 #include "volPointInterpolation.H"
 #include "faceZoneMesh.H"
-#include "faMesh.H"
 #include "areaFields.H"
 #include "fvMeshSubsetProxy.H"
 #include "faceSet.H"
 #include "pointSet.H"
 #include "HashOps.H"
 #include "regionProperties.H"
+#include "stringListOps.H"  // For stringListOps::findMatching()
 
 #include "Cloud.H"
 #include "readFields.H"
@@ -434,7 +434,6 @@ int main(int argc, char *argv[])
     argList::addOptionCompat("one-boundary", {"allPatches", 1806});
 
     #include "addAllRegionOptions.H"
-    #include "addAllFaRegionOptions.H"
 
     argList::addOption
     (
@@ -631,16 +630,6 @@ int main(int argc, char *argv[])
     // Handle -allRegions, -regions, -region
     #include "getAllRegionOptions.H"
 
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
-
-    if (!doFiniteArea)
-    {
-        areaRegionNames.clear();  // For consistency
-    }
-
-    // ------------------------------------------------------------------------
-
     // Names for sets and zones
     word cellSelectionName;
     word faceSetName;
@@ -788,11 +777,8 @@ int main(int argc, char *argv[])
                 }
             }
 
-            // fvMesh fields
             IOobjectList objects;
-
-            // faMesh fields (multiple finite-area regions per volume region)
-            HashTable<IOobjectList> faObjects;
+            IOobjectList faObjects;
 
             if (doConvertFields)
             {
@@ -800,51 +786,33 @@ int main(int argc, char *argv[])
                 objects =
                     IOobjectList(meshProxy.baseMesh(), runTime.timeName());
 
+                // List of area mesh objects (assuming single region)
+                faObjects =
+                    IOobjectList
+                    (
+                        runTime,
+                        runTime.timeName(),
+                        faMesh::dbDir(meshProxy.baseMesh(), word::null),
+                        IOobjectOption::NO_REGISTER
+                    );
+
                 if (fieldSelector)
                 {
                     objects.filterObjects(fieldSelector);
+                    faObjects.filterObjects(fieldSelector);
                 }
+
                 // Remove "*_0" restart fields
                 objects.prune_0();
+                faObjects.prune_0();
 
                 if (!doPointValues)
                 {
                     // Prune point fields if disabled
                     objects.filterClasses(Foam::fieldTypes::is_point, true);
                 }
-
-
-                // Lists of finite-area fields
-                faObjects.reserve(areaRegionNames.size());
-
-                for (const word& areaName : areaRegionNames)
-                {
-                    // The finite-area objects for given area region.
-                    // Add as method to faMeshesRegistry?
-
-                    IOobjectList objs
-                    (
-                        faMesh::Registry(meshProxy.baseMesh()),
-                        runTime.timeName(),
-                        polyMesh::regionName(areaName),
-                        IOobjectOption::NO_REGISTER
-                    );
-
-                    if (fieldSelector)
-                    {
-                        objs.filterObjects(fieldSelector);
-                    }
-                    // Remove "*_0" restart fields
-                    objs.prune_0();
-
-                    if (!objs.empty())
-                    {
-                        faObjects.emplace_set(areaName, std::move(objs));
-                    }
-                }
             }
 
-
             if (processorFieldsOnly)
             {
                 // Processor-patches only and continue

applications/utilities/preProcessing/setFields/Make/options

@@ -1,10 +1,10 @@
 EXE_INC = \
-    -I$(LIB_SRC)/meshTools/lnInclude \
     -I$(LIB_SRC)/finiteVolume/lnInclude \
-    -I$(LIB_SRC)/finiteArea/lnInclude
+    -I$(LIB_SRC)/finiteArea/lnInclude \
+    -I$(LIB_SRC)/meshTools/lnInclude
 
 EXE_LIBS = \
-    -lmeshTools \
     -lfiniteVolume \
     -lfiniteArea \
+    -lmeshTools \
     -lgenericPatchFields

applications/utilities/preProcessing/setFields/setFields.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2022-2025 OpenCFD Ltd.
+    Copyright (C) 2022-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -47,7 +47,6 @@ Description
 #include "areaFields.H"
 #include "coupledFvPatch.H"
 #include "coupledFaPatch.H"
-#include "regionProperties.H"
 
 using namespace Foam;
 
@@ -87,18 +86,17 @@ bool consumeUnusedType(const fieldDescription& fieldDesc, Istream& is)
     //? typedef GeometricField<Type, faePatchField, areaMesh> fieldType3;
     //? typedef GeometricField<Type, fvsPatchField, volMesh>  fieldType4;
 
-    const bool isExpectedType
+    if
     (
         fieldDesc.type() == fieldType1::typeName
      || fieldDesc.type() == fieldType2::typeName
-    );
-
-    if (isExpectedType)
+    )
     {
         (void) pTraits<Type>(is);
+        return true;
     }
 
-    return isExpectedType;
+    return false;
 }
 
 
@@ -124,18 +122,13 @@ bool setCellFieldType
 (
     const fieldDescription& fieldDesc,
     const fvMesh& mesh,
-    const labelUList& selectedCells,
+    const labelList& selectedCells,
     Istream& is
 )
 {
     typedef GeometricField<Type, fvPatchField, volMesh> fieldType;
 
-    const bool isExpectedType
-    (
-        fieldDesc.type() == fieldType::typeName
-    );
-
-    if (!isExpectedType)
+    if (fieldDesc.type() != fieldType::typeName)
     {
         return false;
     }
@@ -150,9 +143,7 @@ bool setCellFieldType
         fieldDesc.name(),
         mesh.thisDb().time().timeName(),
         mesh.thisDb(),
-        IOobjectOption::MUST_READ,
-        IOobjectOption::NO_WRITE,
-        IOobjectOption::NO_REGISTER
+        IOobject::MUST_READ
     );
 
     bool found = fieldHeader.typeHeaderOk<fieldType>(true);
@@ -160,8 +151,13 @@ bool setCellFieldType
     if (!found)
     {
         // Fallback to "constant" directory
-        fieldHeader.resetHeader();
-        fieldHeader.instance() = mesh.thisDb().time().constant();
+        fieldHeader = IOobject
+        (
+            fieldDesc.name(),
+            mesh.thisDb().time().constant(),
+            mesh.thisDb(),
+            IOobject::MUST_READ
+        );
         found = fieldHeader.typeHeaderOk<fieldType>(true);
     }
 
@@ -175,7 +171,7 @@ bool setCellFieldType
 
         fieldType field(fieldHeader, mesh, false);
 
-        if (isNull(selectedCells) || (selectedCells.size() == field.size()))
+        if (isNull(selectedCells) || selectedCells.size() == field.size())
         {
             field.primitiveFieldRef() = fieldValue;
         }
@@ -208,7 +204,7 @@ bool setCellFieldType
             << "Field " << fieldDesc.name() << " not found" << endl;
     }
 
-    return isExpectedType;
+    return true;
 }
 
 
@@ -220,18 +216,13 @@ bool setAreaFieldType
 (
     const fieldDescription& fieldDesc,
     const faMesh& mesh,
-    const labelUList& selectedFaces,
+    const labelList& selectedFaces,
     Istream& is
 )
 {
     typedef GeometricField<Type, faPatchField, areaMesh> fieldType;
 
-    const bool isExpectedType
-    (
-        fieldDesc.type() == fieldType::typeName
-    );
-
-    if (!isExpectedType)
+    if (fieldDesc.type() != fieldType::typeName)
     {
         return false;
     }
@@ -246,9 +237,7 @@ bool setAreaFieldType
         fieldDesc.name(),
         mesh.thisDb().time().timeName(),
         mesh.thisDb(),
-        IOobjectOption::MUST_READ,
-        IOobjectOption::NO_WRITE,
-        IOobjectOption::NO_REGISTER
+        IOobject::MUST_READ
     );
 
     bool found = fieldHeader.typeHeaderOk<fieldType>(true);
@@ -256,8 +245,13 @@ bool setAreaFieldType
     if (!found)
     {
         // Fallback to "constant" directory
-        fieldHeader.resetHeader();
-        fieldHeader.instance() = mesh.thisDb().time().constant(),
+        fieldHeader = IOobject
+        (
+            fieldDesc.name(),
+            mesh.thisDb().time().constant(),
+            mesh.thisDb(),
+            IOobject::MUST_READ
+        );
         found = fieldHeader.typeHeaderOk<fieldType>(true);
     }
 
@@ -298,7 +292,7 @@ bool setAreaFieldType
             << "Field " << fieldDesc.name() << " not found" << endl;
     }
 
-    return isExpectedType;
+    return true;
 }
 
 
@@ -310,18 +304,13 @@ bool setFaceFieldType
 (
     const fieldDescription& fieldDesc,
     const fvMesh& mesh,
-    const labelUList& selectedFaces,
+    const labelList& selectedFaces,
     Istream& is
 )
 {
     typedef GeometricField<Type, fvPatchField, volMesh> fieldType;
 
-    const bool isExpectedType
-    (
-        fieldDesc.type() == fieldType::typeName
-    );
-
-    if (!isExpectedType)
+    if (fieldDesc.type() != fieldType::typeName)
     {
         return false;
     }
@@ -336,9 +325,7 @@ bool setFaceFieldType
         fieldDesc.name(),
         mesh.thisDb().time().timeName(),
         mesh.thisDb(),
-        IOobjectOption::MUST_READ,
-        IOobjectOption::NO_WRITE,
-        IOobjectOption::NO_REGISTER
+        IOobject::MUST_READ
     );
 
     bool found = fieldHeader.typeHeaderOk<fieldType>(true);
@@ -346,8 +333,13 @@ bool setFaceFieldType
     if (!found)
     {
         // Fallback to "constant" directory
-        fieldHeader.resetHeader();
-        fieldHeader.instance() = mesh.thisDb().time().constant();
+        fieldHeader = IOobject
+        (
+            fieldDesc.name(),
+            mesh.thisDb().time().constant(),
+            mesh.thisDb(),
+            IOobject::MUST_READ
+        );
         found = fieldHeader.typeHeaderOk<fieldType>(true);
     }
 
@@ -363,14 +355,15 @@ bool setFaceFieldType
 
         // Create flat list of selected faces and their value.
         Field<Type> allBoundaryValues(mesh.nBoundaryFaces());
-        for (const auto& pfld : field.boundaryField())
+        forAll(field.boundaryField(), patchi)
         {
             SubField<Type>
             (
                 allBoundaryValues,
-                pfld.size(),
-                pfld.patch().offset()
-            ) = pfld;
+                field.boundaryField()[patchi].size(),
+                field.boundaryField()[patchi].patch().start()
+              - mesh.nInternalFaces()
+            ) = field.boundaryField()[patchi];
         }
 
         // Override
@@ -431,7 +424,8 @@ bool setFaceFieldType
                 (
                     allBoundaryValues,
                     fieldBf[patchi].size(),
-                    fieldBf[patchi].patch().offset()
+                    fieldBf[patchi].patch().start()
+                  - mesh.nInternalFaces()
                 );
             }
         }
@@ -451,7 +445,7 @@ bool setFaceFieldType
             << "Field " << fieldDesc.name() << " not found" << endl;
     }
 
-    return isExpectedType;
+    return true;
 }
 
 
@@ -466,7 +460,7 @@ struct setCellField
     (
         const fieldDescription& fieldDesc,
         const fvMesh& m,
-        const labelUList& selectedCells,
+        const labelList& selectedCells,
         Istream& is
     )
     {
@@ -483,11 +477,11 @@ struct setCellField
     class iNew
     {
         const fvMesh& mesh_;
-        const labelUList& selected_;
+        const labelList& selected_;
 
     public:
 
-        iNew(const fvMesh& mesh, const labelUList& selectedCells) noexcept
+        iNew(const fvMesh& mesh, const labelList& selectedCells)
         :
             mesh_(mesh),
             selected_(selectedCells)
@@ -534,7 +528,7 @@ struct setFaceField
     (
         const fieldDescription& fieldDesc,
         const fvMesh& m,
-        const labelUList& selectedFaces,
+        const labelList& selectedFaces,
         Istream& is
     )
     {
@@ -551,11 +545,11 @@ struct setFaceField
     class iNew
     {
         const fvMesh& mesh_;
-        const labelUList& selected_;
+        const labelList& selected_;
 
     public:
 
-        iNew(const fvMesh& mesh, const labelUList& selectedFaces) noexcept
+        iNew(const fvMesh& mesh, const labelList& selectedFaces)
         :
             mesh_(mesh),
             selected_(selectedFaces)
@@ -602,7 +596,7 @@ struct setAreaField
     (
         const fieldDescription& fieldDesc,
         const faMesh& m,
-        const labelUList& selectedFaces,
+        const labelList& selectedFaces,
         Istream& is
     )
     {
@@ -619,11 +613,11 @@ struct setAreaField
     class iNew
     {
         const faMesh& mesh_;
-        const labelUList& selected_;
+        const labelList& selected_;
 
     public:
 
-        iNew(const faMesh& mesh, const labelUList& selectedFaces) noexcept
+        iNew(const faMesh& mesh, const labelList& selectedFaces)
         :
             mesh_(mesh),
             selected_(selectedFaces)
@@ -681,7 +675,6 @@ int main(int argc, char *argv[])
     );
 
     #include "addRegionOption.H"
-    #include "addAllFaRegionOptions.H"
 
     // -------------------------
 
@@ -693,59 +686,15 @@ int main(int argc, char *argv[])
 
     #include "createNamedMesh.H"
 
-    // Handle -all-area-regions, -area-regions, -area-region
-    #include "getAllFaRegionOptions.H"
+    autoPtr<faMesh> faMeshPtr;
 
-    if (args.found("no-finite-area"))
+    if (!args.found("no-finite-area"))
     {
-        areaRegionNames.clear();  // For consistency
+        faMeshPtr = faMesh::TryNew(mesh);
     }
-
-    // ------------------------------------------------------------------------
-
-    PtrList<faMesh> faMeshes;
-
-    // Setup all area meshes on this region
-    if (!areaRegionNames.empty())  // ie, !args.found("no-finite-area")
+    if (faMeshPtr)
     {
-        faMeshes.resize(areaRegionNames.size());
-
-        label nGoodRegions(0);
-
-        for (const word& areaName : areaRegionNames)
-        {
-            autoPtr<faMesh> faMeshPtr = faMesh::TryNew(areaName, mesh);
-
-            if (faMeshPtr)
-            {
-                faMeshes.set(nGoodRegions++, std::move(faMeshPtr));
-            }
-        }
-
-        faMeshes.resize(nGoodRegions);
-    }
-
-    if (faMeshes.size() == 1)
-    {
-        Info<< "Using finite-area mesh";
-        if
-        (
-            const word& name = polyMesh::regionName(faMeshes[0].name());
-            !name.empty()
-        )
-        {
-            Info<< " [" << name << "]";
-        }
-        Info<< nl;
-    }
-    else if (faMeshes.size() > 1)
-    {
-        Info<< "Detected finite-area meshes:";
-        for (const faMesh& areaMesh : faMeshes)
-        {
-            Info<< " [" << areaMesh.name() << "]";
-        }
-        Info<< nl;
+        Info<< "Detected finite-area mesh" << nl;
     }
 
     const word dictName("setFieldsDict");
@@ -763,45 +712,37 @@ int main(int argc, char *argv[])
 
 
     // Default field values
-    if
-    (
-        const auto* eptr
-      = setFieldsDict.findEntry("defaultFieldValues", keyType::LITERAL)
-    )
     {
-        ITstream& is = eptr->stream();
+        const entry* eptr =
+            setFieldsDict.findEntry("defaultFieldValues", keyType::LITERAL);
 
-        Info<< "Setting volume field default values" << endl;
-
-        PtrList<setCellField> defaultFieldValues
-        (
-            is,
-            setCellField::iNew(mesh, labelList::null())
-        );
-
-        for (const faMesh& areaMesh : faMeshes)
+        if (eptr)
         {
-            Info<< "Setting area field default values";
+            ITstream& is = eptr->stream();
 
-            if
-            (
-                const word& name = polyMesh::regionName(areaMesh.name());
-                !name.empty()
-            )
-            {
-                Info<< " [" << name << "]";
-            }
-            Info<< endl;
+            Info<< "Setting volume field default values" << endl;
 
-            is.rewind();
-
-            PtrList<setAreaField> defaultAreaFieldValues
+            PtrList<setCellField> defaultFieldValues
             (
                 is,
-                setAreaField::iNew(areaMesh, labelList::null())
+                setCellField::iNew(mesh, labelList::null())
             );
+
+            if (faMeshPtr)
+            {
+                const faMesh& areaMesh = faMeshPtr();
+                is.rewind();
+
+                Info<< "Setting area field default values" << endl;
+
+                PtrList<setAreaField> defaultFieldValues
+                (
+                    is,
+                    setAreaField::iNew(areaMesh, labelList::null())
+                );
+            }
+            Info<< endl;
         }
-        Info<< endl;
     }
 
 
@@ -827,15 +768,11 @@ int main(int argc, char *argv[])
 
             labelList selectedCells(subset.sortedToc());
 
-            {
-                FixedList<label, 2> stats;
-                stats[0] = selectedCells.size();
-                stats[1] = mesh.nCells();
-                reduce(stats, sumOp<label>());
-
-                Info<< "    Selected " << stats[0] << '/' << stats[1]
-                    << " cells" << nl;
-            }
+            Info<< "    Selected "
+                << returnReduce(selectedCells.size(), sumOp<label>())
+                << '/'
+                << returnReduce(mesh.nCells(), sumOp<label>())
+                << " cells" << nl;
 
             ITstream& is = region.dict().lookup("fieldValues");
 
@@ -869,8 +806,10 @@ int main(int argc, char *argv[])
                 setFaceField::iNew(mesh, selectedFaces)
             );
 
-            for (const faMesh& areaMesh : faMeshes)
+            if (faMeshPtr)
             {
+                const faMesh& areaMesh = faMeshPtr();
+
                 const labelUList& faceLabels = areaMesh.faceLabels();
 
                 // Transcribe from mesh faces to finite-area addressing
@@ -889,15 +828,11 @@ int main(int argc, char *argv[])
                 }
                 areaFaces.resize(nUsed);
 
-                {
-                    FixedList<label, 2> stats;
-                    stats[0] = areaFaces.size();
-                    stats[1] = faceLabels.size();
-                    reduce(stats, sumOp<label>());
-
-                    Info<< "    Selected " << stats[0] << '/' << stats[1]
-                        << " area faces for " << areaMesh.name() << endl;
-                }
+                Info<< "    Selected "
+                    << returnReduce(areaFaces.size(), sumOp<label>())
+                    << '/'
+                    << returnReduce(faceLabels.size(), sumOp<label>())
+                    << " area faces" << nl;
 
                 is.rewind();
 

src/Allwmake

@@ -55,8 +55,6 @@ wmake $targetType fileFormats
 wmake $targetType surfMesh
 wmake $targetType meshTools
 
-#------------------------------------------------------------------------------
-
 wmake $targetType finiteArea
 wmake $targetType finiteVolume
 wmake $targetType fused/finiteVolume

src/OpenFOAM/containers/Lists/List/List.H

@@ -45,6 +45,7 @@ SourceFiles
 
 #include "autoPtr.H"
 #include "UList.H"
+#include "SLListFwd.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -65,7 +66,6 @@ typedef List<bool> boolList;        //!< A List of bools
 typedef List<char> charList;        //!< A List of chars
 typedef List<label> labelList;      //!< A List of labels
 
-
 /*---------------------------------------------------------------------------*\
                            Class List Declaration
 \*---------------------------------------------------------------------------*/
@@ -395,6 +395,37 @@ public:
 
         //- Alias for resize()
         void setSize(label n, const T& val) { this->resize(n, val); }
+
+
+    // Expression templates
+
+        //- Construct from value expression
+        template<typename E>
+        explicit List
+        (
+            const Expression::ListExpression
+            <
+                E,
+                typename E::value_type
+            >& expr
+        )
+        {
+            expr.evaluate(*this);
+        }
+
+        //- Assign values from expression
+        template<typename E>
+        void operator=
+        (
+            const Expression::ListExpression
+            <
+                E,
+                typename E::value_type
+            >& expr
+        )
+        {
+            expr.evaluate(*this);
+        }
 };
 
 

src/OpenFOAM/containers/Lists/List/UList.H

@@ -80,6 +80,11 @@ typedef UList<bool> boolUList;      //!< A UList of bools
 typedef UList<char> charUList;      //!< A UList of chars
 typedef UList<label> labelUList;    //!< A UList of labels
 
+namespace Expression
+{
+template<class E, typename ValType> class ListExpression;
+template<class T> class ListConstRefWrap;
+}
 
 /*---------------------------------------------------------------------------*\
                            Class UList Declaration
@@ -697,6 +702,39 @@ public:
         {
             return this->contains(val, pos);
         }
+
+
+    // Expression templates
+
+        //- Have unique tag
+        using is_List = void;
+
+        //- Wrap value as expression
+        auto expr() const
+        {
+            return Expression::ListConstRefWrap<T>
+            (
+                reinterpret_cast<const List<T>&>(*this)
+            );
+        }
+
+        //- Assign values from expression
+        template<typename E>
+        void operator=
+        (
+            const Expression::ListExpression
+            <
+                E,
+                typename E::value_type
+            >& expr
+        )
+        {
+            // bypass expr.evaluate to avoid resize ...
+            for (label i = 0; i < expr.size(); ++i)
+            {
+                operator[](i) = expr[i];
+            }
+        }
 };
 
 

src/OpenFOAM/dimensionedTypes/dimensionedType/dimensionedType.H

@@ -60,6 +60,12 @@ template<class Type> class dimensioned;
 template<class Type>
 Istream& operator>>(Istream& is, dimensioned<Type>& dt);
 
+namespace Expression
+{
+template<class T> class UniformListWrap;
+template<class GeoField> class UniformGeometricFieldWrap;
+}
+
 /*---------------------------------------------------------------------------*\
                            Class dimensioned Declaration
 \*---------------------------------------------------------------------------*/
@@ -449,6 +455,28 @@ public:
         {
             return getOrAddToDict(name, dict, deflt);
         }
+
+
+    // Expression templates
+
+        //- Wrap value as constant-value List expression
+        auto expr(const label size) const
+        {
+            return Expression::UniformListWrap<Type>(size, value_);
+        }
+
+        //- Wrap value as constant-value GeometricField expression. Supplied
+        //  fields is used for sizing only and needs to be valid at time of
+        //  evaluation.
+        template<class GeoField>
+        auto expr(const GeoField& fld) const
+        {
+            return Expression::UniformGeometricFieldWrap<GeoField>
+            (
+                fld,
+                *this
+            );
+        }
 };
 
 

src/OpenFOAM/expressionTemplates/GenericExpression.H

@@ -0,0 +1,252 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2025 M. Janssens
+-------------------------------------------------------------------------------
+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/>.
+
+Namespace
+    Foam::GenericExpression
+
+Description
+    Expression templates.
+
+SourceFiles
+    GenericExpression.H
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef Foam_GenericExpression_H
+#define Foam_GenericExpression_H
+
+#include <cassert>
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace Expression
+{
+
+/*---------------------------------------------------------------------------*\
+                     Class GenericExpression Declarations
+\*---------------------------------------------------------------------------*/
+
+template<typename E>
+class GenericExpression
+{
+public:
+    static constexpr bool is_leaf = false;
+
+    auto evaluate() const
+    {
+        // Delegation to the actual expression type. This avoids dynamic
+        // polymorphism (a.k.a. virtual functions in C++)
+        return static_cast<E const&>(*this).evaluate();
+    }
+};
+
+
+// Macros
+// ~~~~~~
+
+#define EXPRESSION_FUNCTION1(BaseClass, Func, BaseFunc, OpFunc)                \
+template<typename E1>                                                          \
+class OpFunc                                                                   \
+:                                                                              \
+    public BaseClass<OpFunc<E1>>                                               \
+{                                                                              \
+    typename std::conditional<E1::is_leaf, const E1&, const E1>::type u_;      \
+                                                                               \
+public:                                                                        \
+    static constexpr bool is_leaf = false;                                     \
+                                                                               \
+    OpFunc(const E1& u)                                                        \
+    :                                                                          \
+        u_(u)                                                                  \
+    {}                                                                         \
+                                                                               \
+    auto evaluate() const                                                      \
+    {                                                                          \
+        return BaseFunc(u_.evaluate());                                        \
+    }                                                                          \
+};                                                                             \
+template<typename E1>                                                          \
+OpFunc<E1> Func                                                                \
+(                                                                              \
+    const BaseClass<E1>& u                                                     \
+)                                                                              \
+{                                                                              \
+    return OpFunc<E1>(static_cast<const E1&>(u));                              \
+}
+
+
+#define EXPRESSION_FUNCTION2(BaseClass, Func, BaseFunc, OpFunc)                \
+template<typename E1, typename E2>                                             \
+class OpFunc                                                                   \
+:                                                                              \
+    public BaseClass<OpFunc<E1, E2>>                                           \
+{                                                                              \
+    typename std::conditional<E1::is_leaf, const E1&, const E1>::type u_;      \
+    typename std::conditional<E2::is_leaf, const E2&, const E2>::type v_;      \
+                                                                               \
+public:                                                                        \
+    static constexpr bool is_leaf = false;                                     \
+                                                                               \
+    OpFunc(const E1& u, const E2& v)                                           \
+    :                                                                          \
+     u_(u), v_(v)                                                              \
+    {}                                                                         \
+    auto evaluate() const                                                      \
+    {                                                                          \
+        return BaseFunc(u_.evaluate(), v_.evaluate());                         \
+    }                                                                          \
+};                                                                             \
+template<typename E1, typename E2>                                             \
+OpFunc<E1, E2> Func                                                            \
+(                                                                              \
+    const BaseClass<E1>& u,                                                    \
+    const BaseClass<E2>& v                                                     \
+)                                                                              \
+{                                                                              \
+    return OpFunc<E1, E2>                                                      \
+    (                                                                          \
+        static_cast<const E1&>(u),                                             \
+        static_cast<const E2&>(v)                                              \
+    );                                                                         \
+}
+
+
+#define EXPRESSION_OPERATOR(BaseClass, Op, BaseOp, OpFunc)                     \
+template<typename E1, typename E2>                                             \
+class OpFunc                                                                   \
+:                                                                              \
+    public BaseClass                                                           \
+    <                                                                          \
+        OpFunc<E1, E2>                                                         \
+    >                                                                          \
+{                                                                              \
+    /* cref if leaf, copy otherwise */                                         \
+    typename std::conditional<E1::is_leaf, const E1&, const E1>::type u_;      \
+    typename std::conditional<E2::is_leaf, const E2&, const E2>::type v_;      \
+                                                                               \
+public:                                                                        \
+    static constexpr bool is_leaf = false;                                     \
+                                                                               \
+    OpFunc(const E1& u, const E2& v)                                           \
+    :                                                                          \
+     u_(u), v_(v)                                                              \
+    {}                                                                         \
+    auto evaluate() const                                                      \
+    {                                                                          \
+        return u_.evaluate() BaseOp v_.evaluate();                             \
+    }                                                                          \
+};                                                                             \
+template<typename E1, typename E2>                                             \
+OpFunc<E1, E2>                                                                 \
+operator Op                                                                    \
+(                                                                              \
+    BaseClass<E1> const& u,                                                    \
+    BaseClass<E2> const& v                                                     \
+)                                                                              \
+{                                                                              \
+    return OpFunc<E1, E2>                                                      \
+    (                                                                          \
+        static_cast<const E1&>(u),                                             \
+        static_cast<const E2&>(v)                                              \
+    );                                                                         \
+}
+
+
+// Do '-' separately until we work out macro expansion...
+template<typename E1>
+class g_negate
+:
+    public GenericExpression
+    <
+        g_negate<E1>
+    >
+{
+    typename std::conditional<E1::is_leaf, const E1&, const E1>::type u_;
+
+public:
+    static constexpr bool is_leaf = false;
+
+    g_negate(const E1& u)
+    :
+        u_(u)
+    {}
+
+    auto evaluate() const
+    {
+        return -u_.evaluate();
+    }
+};
+template<typename E1>
+g_negate<E1> operator-
+(
+    const GenericExpression<E1>& u
+)
+{
+    return g_negate<E1>(static_cast<const E1&>(u));
+}
+
+
+EXPRESSION_FUNCTION1(GenericExpression, sqr, Foam::sqr, g_sqr)
+EXPRESSION_FUNCTION1(GenericExpression, sqrt, Foam::sqrt, g_sqrt)
+EXPRESSION_FUNCTION1(GenericExpression, magSqr, Foam::magSqr, g_magSqr)
+EXPRESSION_FUNCTION1(GenericExpression, symm, Foam::symm, g_symm)
+EXPRESSION_FUNCTION1(GenericExpression, pow2, Foam::pow2, g_pow2)
+EXPRESSION_FUNCTION1(GenericExpression, pow3, Foam::pow3, g_pow3)
+EXPRESSION_FUNCTION1(GenericExpression, pow4, Foam::pow4, g_pow4)
+EXPRESSION_FUNCTION1(GenericExpression, operator~, Foam::operator~, g_compl)
+
+//TBD. Parse problem
+//EXPRESSION_FUNCTION1(GenericExpression, operator!, Foam::operator!, g_not)
+
+#undef EXPRESSION_FUNCTION1
+
+EXPRESSION_FUNCTION2(GenericExpression, operator+, Foam::operator+, g_add);
+EXPRESSION_FUNCTION2(GenericExpression, operator-, Foam::operator-, g_subtract);
+EXPRESSION_FUNCTION2(GenericExpression, operator*, Foam::operator*, g_multiply);
+EXPRESSION_FUNCTION2(GenericExpression, operator/, Foam::operator/, g_divide);
+
+#undef EXPRESSION_FUNCTION2
+
+EXPRESSION_OPERATOR(GenericExpression, ||, ||, g_or)
+EXPRESSION_OPERATOR(GenericExpression, &&, &&, g_and)
+EXPRESSION_OPERATOR(GenericExpression, &, &, g_bitand)
+EXPRESSION_OPERATOR(GenericExpression, |, |, g_bitor)
+EXPRESSION_OPERATOR(GenericExpression, ^, ^, g_xor)
+
+#undef EXPRESSION_OPERATOR
+
+} // End namespace Expression
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/OpenFOAM/expressionTemplates/boolExpression.H

@@ -0,0 +1,145 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2025 M. Janssens
+-------------------------------------------------------------------------------
+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/>.
+
+Namespace
+    Foam::boolExpression
+
+Description
+    Expression templates for bool
+
+SourceFiles
+    boolExpression.H
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef Foam_boolExpression_H
+#define Foam_boolExpression_H
+
+#include "GenericExpression.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace Expression
+{
+
+/*---------------------------------------------------------------------------*\
+                       Namespace Expression Declarations
+\*---------------------------------------------------------------------------*/
+
+// Wrap of non-const bool
+// ~~~~~~~~~~~~~~~~~~~~~~
+
+class boolWrap
+:
+    public GenericExpression<boolWrap>
+{
+    bool elems_;
+
+public:
+    static constexpr bool is_leaf = false;  //true;
+
+    //- Construct from components
+    boolWrap(const bool elems)
+    :
+        elems_(elems)
+    {}
+
+    // Construct from GenericExpression, forcing its evaluation.
+    template<typename E>
+    boolWrap
+    (
+        const GenericExpression<E>& expr
+    )
+    :
+        elems_(expr.evaluate())
+    {}
+
+    auto evaluate() const
+    {
+        return elems_;
+    }
+
+    template<typename E>
+    auto evaluate
+    (
+        const GenericExpression<E>& expr
+    )
+    {
+        elems_ = expr.evaluate();
+        return elems_;
+    }
+
+    //- Assignment
+    template<typename E>
+    void operator=
+    (
+        const GenericExpression<E>& expr
+    )
+    {
+        elems_ = expr.evaluate();
+    }
+};
+
+
+// Wrap of const bool
+// ~~~~~~~~~~~~~~~~~~
+
+class boolConstWrap
+:
+    public GenericExpression<boolConstWrap>
+{
+    const bool elems_;
+
+public:
+
+    // ! Store as copy (since holds reference)
+    static constexpr bool is_leaf = false;
+
+    // construct from components
+    boolConstWrap(const bool elems)
+    :
+        elems_(elems)
+    {}
+
+    auto evaluate() const
+    {
+        return elems_;
+    }
+};
+
+
+} // End namespace Expression
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/OpenFOAM/expressionTemplates/dimensionSetExpression.H

@@ -0,0 +1,148 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2025 M. Janssens
+-------------------------------------------------------------------------------
+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/>.
+
+Namespace
+    Foam::dimensionSetExpression
+
+Description
+    Expression templates for dimensionSet
+
+SourceFiles
+    dimensionSetExpression.H
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef Foam_dimensionSetExpression_H
+#define Foam_dimensionSetExpression_H
+
+#include "GenericExpression.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace Expression
+{
+
+/*---------------------------------------------------------------------------*\
+                       Namespace Expression Declarations
+\*---------------------------------------------------------------------------*/
+
+// Wrap of non-const reference to dimensionSet
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+class dimensionSetRefWrap
+:
+    public GenericExpression<dimensionSetRefWrap>
+{
+    dimensionSet& elems_;
+
+public:
+    static constexpr bool is_leaf = false;  //true;
+
+    //- Construct from components
+    dimensionSetRefWrap(dimensionSet& elems)
+    :
+        elems_(elems)
+    {}
+
+    // Construct from GenericExpression, forcing its evaluation.
+    template<typename E>
+    dimensionSetRefWrap
+    (
+        dimensionSet& elems,
+        const GenericExpression<E>& expr
+    )
+    :
+        elems_(elems)
+    {
+        elems_ = expr.evaluate();
+    }
+
+    auto evaluate() const
+    {
+        return elems_;
+    }
+
+    template<typename E>
+    auto& evaluate
+    (
+        const GenericExpression<E>& expr
+    )
+    {
+        elems_ = expr.evaluate();
+        return elems_;
+    }
+
+    //- Assignment
+    template<typename E>
+    void operator=
+    (
+        const GenericExpression<E>& expr
+    )
+    {
+        elems_ = expr.evaluate();
+    }
+};
+
+
+// Wrap of const reference to dimensionSet
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+class dimensionSetConstRefWrap
+:
+    public GenericExpression<dimensionSetConstRefWrap>
+{
+    const dimensionSet& elems_;
+
+public:
+
+    // ! Store as copy (since holds reference)
+    static constexpr bool is_leaf = false;
+
+    // construct from components
+    dimensionSetConstRefWrap(const dimensionSet& elems)
+    :
+        elems_(elems)
+    {}
+
+    auto evaluate() const
+    {
+        return elems_;
+    }
+};
+
+
+} // End namespace Expression
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/OpenFOAM/fields/Fields/Field/Field.H

@@ -582,6 +582,37 @@ public:
 
         friend Ostream& operator<< <Type>
         (Ostream&, const tmp<Field<Type>>&);
+
+
+    // Expression templates
+
+        //- Construct from value expression
+        template<typename E>
+        explicit Field
+        (
+            const Expression::ListExpression
+            <
+                E,
+                typename E::value_type
+            >& expr
+        )
+        {
+            expr.evaluate(*this);
+        }
+
+        //- Assign values from expression
+        template<typename E>
+        void operator=
+        (
+            const Expression::ListExpression
+            <
+                E,
+                typename E::value_type
+            >& expr
+        )
+        {
+            expr.evaluate(*this);
+        }
 };
 
 

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

@@ -1675,6 +1675,124 @@ Foam::Ostream& Foam::operator<<
 }
 
 
+// * * * * * * * * * * * * * Expression Templates  * * * * * * * * * * * * * //
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+template<typename E>
+Foam::GeometricField<Type, PatchField, GeoMesh>::GeometricField
+(
+    const IOobject& io,
+    const Mesh& mesh,
+    const Expression::GeometricFieldExpression
+    <
+        E,
+        typename E::IntExpr,
+        typename E::UncoupledPatchExpr,
+        typename E::CoupledPatchExpr,
+        typename E::value_type
+    >& expr
+)
+:
+    Internal(io, mesh, expr.dimensions(), false),
+    timeIndex_(this->time().timeIndex()),
+    boundaryField_(mesh.boundary(), *this, PatchField<Type>::calculatedType())
+{
+    DebugInFunction
+        << "Creating from expression " << nl << this->info() << endl;
+
+    bool hasRead = readIfPresent();
+    if (!hasRead)
+    {
+        expr.evaluate(*this);
+    }
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+template<typename E>
+Foam::GeometricField<Type, PatchField, GeoMesh>::GeometricField
+(
+    const word& name,
+    const Mesh& mesh,
+    const Expression::GeometricFieldExpression
+    <
+        E,
+        typename E::IntExpr,
+        typename E::UncoupledPatchExpr,
+        typename E::CoupledPatchExpr,
+        typename E::value_type
+    >& expr
+)
+:
+    Internal
+    (
+        IOobject
+        (
+            name,
+            mesh.time().timeName(),
+            mesh.thisDb()
+        ),
+        mesh,
+        expr.dimensions(),
+        false
+    ),
+    timeIndex_(this->time().timeIndex()),
+    boundaryField_(mesh.boundary(), *this, PatchField<Type>::calculatedType())
+{
+    DebugInFunction
+        << "Creating from expression " << nl << this->info() << endl;
+
+    expr.evaluate(*this);
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+Foam::Expression::GeometricFieldConstRefWrap
+<
+    Foam::GeometricField<Type, PatchField, GeoMesh>
+>
+Foam::GeometricField<Type, PatchField, GeoMesh>::expr() const
+{
+    return Expression::GeometricFieldConstRefWrap<this_type>(*this);
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+template<typename E>
+void Foam::GeometricField<Type, PatchField, GeoMesh>::operator=
+(
+    const Expression::GeometricFieldExpression
+    <
+        E,
+        typename E::IntExpr,
+        typename E::UncoupledPatchExpr,
+        typename E::CoupledPatchExpr,
+        typename E::value_type
+    >& expr
+)
+{
+    Expression::GeometricFieldRefWrap<this_type>(*this, expr);
+}
+
+
+template<class Type, template<class> class PatchField, class GeoMesh>
+template<typename E>
+void Foam::GeometricField<Type, PatchField, GeoMesh>::operator==
+(
+    const Expression::GeometricFieldExpression
+    <
+        E,
+        typename E::IntExpr,
+        typename E::UncoupledPatchExpr,
+        typename E::CoupledPatchExpr,
+        typename E::value_type
+    >& expr
+)
+{
+    expr.evaluate(*this, true);
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 #undef checkField

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

@@ -42,6 +42,7 @@ SourceFiles
 #define Foam_GeometricField_H
 
 #include "GeometricBoundaryField.H"
+#include "GeometricFieldExpression.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -1142,6 +1143,79 @@ public:
         {
             return this->clamp_range(lo.value(), hi.value());
         }
+
+
+    // Expression templates
+
+        //- Have unique tag
+        using is_GeometricField = void;
+
+        //- Construct from IOobject and value expression. Supports
+        //  read_if_present
+        template<typename E>
+        GeometricField
+        (
+            const IOobject& io,
+            const Mesh& mesh,
+            const Expression::GeometricFieldExpression
+            <
+                E,
+                typename E::IntExpr,
+                typename E::UncoupledPatchExpr,
+                typename E::CoupledPatchExpr,
+                typename E::value_type
+            >& expr
+        );
+
+        //- Construct from name, mesh and value expression.
+        template<typename E>
+        GeometricField
+        (
+            const word& name,
+            const Mesh& mesh,
+            const Expression::GeometricFieldExpression
+            <
+                E,
+                typename E::IntExpr,
+                typename E::UncoupledPatchExpr,
+                typename E::CoupledPatchExpr,
+                typename E::value_type
+            >& expr
+        );
+
+        //- Wrap value as expression
+        typename Expression::GeometricFieldConstRefWrap
+        <
+            this_type
+        > expr() const;
+
+        //- Assign values from expression
+        template<typename E>
+        void operator=
+        (
+            const Expression::GeometricFieldExpression
+            <
+                E,
+                typename E::IntExpr,
+                typename E::UncoupledPatchExpr,
+                typename E::CoupledPatchExpr,
+                typename E::value_type
+            >& expr
+        );
+
+        //- Assign values from expression. Override asssignable.
+        template<typename E>
+        void operator==
+        (
+            const Expression::GeometricFieldExpression
+            <
+                E,
+                typename E::IntExpr,
+                typename E::UncoupledPatchExpr,
+                typename E::CoupledPatchExpr,
+                typename E::value_type
+            >& expr
+        );
 };
 
 

src/OpenFOAM/memory/tmp/tmp.H

@@ -59,8 +59,17 @@ See also
 namespace Foam
 {
 
+namespace Expression
+{
+template<class GeoField> class GeometricFieldConstTmpWrap;
+template<class T> class ListConstTmpWrap;
+}
+
 // Forward Declarations
 template<class T> class refPtr;
+template<class T> class tmp;
+template<class Type, template<class> class PatchField, class GeoMesh>
+class GeometricField;
 
 /*---------------------------------------------------------------------------*\
                              Class tmp Declaration
@@ -352,6 +361,33 @@ public:
         //  \deprecated(2020-07) - use bool operator
         FOAM_DEPRECATED_FOR(2020-07, "bool operator")
         bool empty() const noexcept { return !ptr_; }
+
+
+    // Expression templates
+
+        //- Wrap value as expression
+        auto expr() const
+        {
+            // Add 'using is_GeometricField = void' to GeometricField
+            // Add 'using is_List = void' to List
+
+            if constexpr
+            (
+                std::is_void_v<typename T::is_GeometricField>
+            )
+            {
+                return Expression::GeometricFieldConstTmpWrap<T>(*this);
+            }
+            else //if constexpr (std::is_void_v<T::is_List>)
+            {
+                return Expression::ListConstTmpWrap<T>(*this);
+            }
+            //else
+            //{
+            //    //static_assert("XXX",YYY);
+            //    return;
+            //}
+        }
 };
 
 

src/OpenFOAM/memory/tmp/tmpI.H

@@ -131,7 +131,7 @@ inline Foam::tmp<T>::tmp(const tmp<T>& rhs)
         if (ptr_)
         {
             ptr_->refCount::operator++();
-            this->checkUseCount();
+            //this->checkUseCount();
         }
         else
         {
@@ -162,7 +162,7 @@ inline Foam::tmp<T>::tmp(const tmp<T>& rhs, bool reuse)
             else
             {
                 ptr_->refCount::operator++();
-                this->checkUseCount();
+                //this->checkUseCount();
             }
         }
         else

src/Pstream/mpi/UPstreamRequest.C

@@ -855,7 +855,7 @@ bool Foam::UPstream::finishedRequest(const label i)
     // This allows MPI to progress behind the scenes if it wishes.
 
     int flag = 0;
-    if (i < 0 || i >= PstreamGlobals::outstandingRequests_.size())
+    if (i >= 0 && i < PstreamGlobals::outstandingRequests_.size())
     {
         auto& request = PstreamGlobals::outstandingRequests_[i];
 

src/atmosphericModels/derivedFvPatchFields/atmBoundaryLayer/atmBoundaryLayer.C

@@ -218,9 +218,11 @@ tmp<vectorField> atmBoundaryLayer::U(const vectorField& pCf) const
     const scalar groundMin = zDir() & ppMin_;
 
     // (YGCJ:Table 1, RH:Eq. 6, HW:Eq. 5)
+    scalarField zEff(max((zDir() & pCf) - groundMin - d + z0, z0));
+
     scalarField Un
     (
-        (Ustar(z0)/kappa_)*log(((zDir() & pCf) - groundMin - d + z0)/z0)
+        (Ustar(z0)/kappa_)*log(zEff/z0)
     );
 
     return flowDir()*Un;
@@ -235,9 +237,9 @@ tmp<scalarField> atmBoundaryLayer::k(const vectorField& pCf) const
     const scalar groundMin = zDir() & ppMin_;
 
     // (YGCJ:Eq. 21; RH:Eq. 7, HW:Eq. 6 when C1=0 and C2=1)
-    return
-        sqr(Ustar(z0))/sqrt(Cmu_)
-       *sqrt(C1_*log(((zDir() & pCf) - groundMin - d + z0)/z0) + C2_);
+    scalarField zEff(max((zDir() & pCf) - groundMin - d + z0, z0));
+
+    return sqr(Ustar(z0))/sqrt(Cmu_)*sqrt(C1_*log(zEff/z0) + C2_);
 }
 
 
@@ -249,9 +251,9 @@ tmp<scalarField> atmBoundaryLayer::epsilon(const vectorField& pCf) const
     const scalar groundMin = zDir() & ppMin_;
 
     // (YGCJ:Eq. 22; RH:Eq. 8, HW:Eq. 7 when C1=0 and C2=1)
-    return
-        pow3(Ustar(z0))/(kappa_*((zDir() & pCf) - groundMin - d + z0))
-       *sqrt(C1_*log(((zDir() & pCf) - groundMin - d + z0)/z0) + C2_);
+    scalarField zEff(max((zDir() & pCf) - groundMin - d + z0, z0));
+
+    return pow3(Ustar(z0))/(kappa_*zEff)*sqrt(C1_*log(zEff/z0) + C2_);
 }
 
 
@@ -263,7 +265,9 @@ tmp<scalarField> atmBoundaryLayer::omega(const vectorField& pCf) const
     const scalar groundMin = zDir() & ppMin_;
 
     // (YGJ:Eq. 13)
-    return Ustar(z0)/(kappa_*sqrt(Cmu_)*((zDir() & pCf) - groundMin - d + z0));
+    scalarField zEff(max((zDir() & pCf) - groundMin - d + z0, z0));
+
+    return Ustar(z0)/(kappa_*sqrt(Cmu_)*zEff);
 }
 
 

src/faOptions/Make/files

@@ -9,7 +9,7 @@ faceSetOption/faceSetOption.C
 derivedSources=sources/derived
 
 $(derivedSources)/externalHeatFluxSource/externalHeatFluxSource.C
-$(derivedSources)/jouleHeatingSource/jouleHeatingSource.cxx
+$(derivedSources)/jouleHeatingSource/jouleHeatingSource.C
 $(derivedSources)/contactHeatFluxSource/contactHeatFluxSource.C
 $(derivedSources)/externalFileSource/externalFileSource.C
 

src/faOptions/faOption/faOption.C

@@ -81,33 +81,6 @@ Foam::fa::option::option
     active_(dict.getOrDefault("active", true)),
     log(true)
 {
-    // Suffix hint for variable names
-    if
-    (
-        coeffs_.readIfPresent("suffixing", suffixHint_)
-     || dict.readIfPresent("suffixing", suffixHint_)
-    )
-    {
-        Switch sw = Switch::find(suffixHint_);
-
-        if (sw.good())
-        {
-            if (!sw)  // No suffix
-            {
-                suffixHint_.clear();
-            }
-        }
-        else if (suffixHint_ == "default")
-        {
-            sw = true;
-        }
-
-        if (sw)  // Default suffix
-        {
-            suffixHint_ = '_' + regionName_;
-        }
-    }
-
     if (dict.readIfPresent("area", areaName_))
     {
         if (!sameRegionNames(areaName_, defaultAreaName))
@@ -122,14 +95,9 @@ Foam::fa::option::option
         }
     }
 
-    Log << incrIndent << indent << "Source: " << name_;
-
-    if (!polyMesh::regionName(areaName_).empty())
-    {
-        Log<< " [" << areaName_ << ']';
-    }
-
-    Info<< decrIndent << endl;
+    Log << incrIndent << indent << "Source: " << name_
+        << " [" << polyMesh::regionName(areaName_) << ']' << endl
+        << decrIndent;
 }
 
 
@@ -149,20 +117,13 @@ Foam::autoPtr<Foam::fa::option> Foam::fa::option::New
     coeffs.readIfPresent("area", areaName);
 
     Info<< indent
-        << "Selecting finite-area option, type " << modelType;
+        << "Selecting finite-area option, type " << modelType
+        << " [" << polyMesh::regionName(areaName) << ']';
 
-    if (sameRegionNames(areaName, defaultAreaName))
+    if (!sameRegionNames(areaName, defaultAreaName))
     {
-        if (!polyMesh::regionName(areaName).empty())
-        {
-            Info<< " [" << areaName << ']';
-        }
+        Info<< " != " << defaultAreaName << nl;
     }
-    else
-    {
-        Info<< " [" << areaName << "] != [" << defaultAreaName << ']';
-    }
-
     Info<< endl;
 
     mesh.time().libs().open

src/faOptions/faOption/faOption.H

@@ -65,13 +65,10 @@ Usage
                     --> the selected faOption settings | dictionary | no | -
       active   | Flag to (de)activate faOption         | bool  | no   | true
       log      | Flag to log faOption-related info     | bool  | no   | true
-      suffixing | Suffix hint for option variables     | word  | no   | -
     \endtable
 
 Note
   - Source/sink options are to be added to the right-hand side of equations.
-  - Suffixing (true|false|none|default|...) currently selects between
-    no suffix and ('_'+region).
 
 SourceFiles
     faOption.C
@@ -139,9 +136,6 @@ protected:
         //- The model region name (finite-area)
         word regionName_;
 
-        //- Suffix hint for variable names (default: "")
-        word suffixHint_;
-
 
     // Protected Member Functions
 
@@ -279,7 +273,7 @@ public:
         //- The source name
         const word& name() const noexcept { return name_; }
 
-        //- Return const access to the volume mesh
+        //- Return const access to the mesh database
         const fvMesh& mesh() const noexcept { return mesh_; }
 
         //- Return dictionary
@@ -310,18 +304,6 @@ public:
         inline bool active(bool on) noexcept;
 
 
-    // Helper Functions
-
-        //- The suffix hint when generating variable names
-        const word& suffixHint() const noexcept { return suffixHint_; }
-
-        //- Return the concatenation of \p base and the suffix hint
-        inline word suffixed(const char* base) const;
-
-        //- Return the concatenation of \p base and the suffix hint
-        inline word suffixed(const std::string& base) const;
-
-
     // Checks
 
         //- Is the source active?

src/faOptions/faOption/faOptionI.H

@@ -61,18 +61,4 @@ inline const Foam::volSurfaceMapping& Foam::fa::option::vsm() const
 }
 
 
-inline Foam::word
-Foam::fa::option::suffixed(const char* base) const
-{
-    return word(base + suffixHint_);
-}
-
-
-inline Foam::word
-Foam::fa::option::suffixed(const std::string& base) const
-{
-    return word(base + suffixHint_);
-}
-
-
 // ************************************************************************* //

src/faOptions/faOption/faOptions.C

@@ -27,6 +27,7 @@ License
 
 #include "faOptions.H"
 #include "faMesh.H"
+#include "faMeshesRegistry.H"
 #include "Time.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
@@ -67,7 +68,7 @@ Foam::IOobject createIOobject
         lookupName,
         mesh.time().constant(),
         // located under finite-area
-        faMesh::Registry(mesh),
+        faMeshesRegistry::New(mesh).thisDb(),
         IOobjectOption::MUST_READ,
         IOobjectOption::NO_WRITE,
         IOobjectOption::REGISTER
@@ -187,7 +188,11 @@ Foam::fa::options& Foam::fa::options::New
     );
 
     // Registered under finite-area?
-    auto* ptr = faMesh::Registry(mesh).getObjectPtr<fa::options>(lookupName);
+    auto* ptr =
+        faMeshesRegistry::New(mesh).thisDb().getObjectPtr<fa::options>
+        (
+            lookupName
+        );
 
     if (!ptr && polyMesh::regionName(defaultAreaName).empty())
     {

src/faOptions/sources/derived/contactHeatFluxSource/contactHeatFluxSource.C

@@ -30,6 +30,7 @@ License
 #include "addToRunTimeSelectionTable.H"
 #include "volFields.H"
 #include "famSup.H"
+#include "zeroGradientFaPatchFields.H"
 
 // * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
 
@@ -56,10 +57,13 @@ Foam::fa::contactHeatFluxSource::contactHeatFluxSource
 :
     fa::faceSetOption(sourceName, modelType, dict, mesh, defaultAreaName),
     TName_(dict.getOrDefault<word>("T", "T")),
-    TprimaryName_(dict.getOrDefault<word>("Tprimary", "T")),
+    TprimaryName_(dict.get<word>("Tprimary")),
     Tprimary_(mesh_.lookupObject<volScalarField>(TprimaryName_)),
+    thicknessLayers_(),
+    kappaLayers_(),
     contactRes_(0),
-    curTimeIndex_(-1)
+    curTimeIndex_(-1),
+    coupling_()
 {
     fieldNames_.resize(1, TName_);
 
@@ -127,30 +131,30 @@ void Foam::fa::contactHeatFluxSource::addSup
     const label fieldi
 )
 {
-    if (!isActive())
+    if (isActive())
     {
-        return;
-    }
+        DebugInfo
+            << name() << ": applying source to "
+            << eqn.psi().name() << endl;
 
-    DebugInfo<< name() << ": applying source to " << eqn.psi().name() << endl;
+        if (curTimeIndex_ != mesh().time().timeIndex())
+        {
+            tmp<DimensionedField<scalar, areaMesh>> htcw(htc());
 
-    if (curTimeIndex_ != mesh().time().timeIndex())
-    {
-        tmp<DimensionedField<scalar, areaMesh>> htcw(htc());
+            // Wall temperature - mapped from primary field to finite-area
+            auto Twall = DimensionedField<scalar, areaMesh>::New
+            (
+                "Tw_" + option::name(),
+                regionMesh(),
+                dimensionedScalar(dimTemperature, Zero)
+            );
 
-        // Wall temperature - mapped from primary field to finite-area
-        auto Twall = DimensionedField<scalar, areaMesh>::New
-        (
-            "Tw_" + option::name(),
-            regionMesh(),
-            dimensionedScalar(dimTemperature, Zero)
-        );
+            vsm().mapInternalToSurface<scalar>(Tprimary_, Twall.ref().field());
 
-        vsm().mapInternalToSurface<scalar>(Tprimary_, Twall.ref().field());
+            eqn += -fam::Sp(htcw(), eqn.psi()) + htcw()*Twall;
 
-        eqn += -fam::Sp(htcw(), eqn.psi()) + htcw()*Twall;
-
-        curTimeIndex_ = mesh().time().timeIndex();
+            curTimeIndex_ = mesh().time().timeIndex();
+        }
     }
 }
 
@@ -186,14 +190,8 @@ bool Foam::fa::contactHeatFluxSource::read(const dictionary& dict)
 
         const labelList& patches = regionMesh().whichPolyPatches();
 
-        if (patches.empty())
-        {
-            coupling_.clear();
-        }
-        else
-        {
-            coupling_.resize_null(patches.back()+1);
-        }
+        coupling_.clear();
+        coupling_.resize(patches.empty() ? 0 : (patches.last()+1));
 
         for (const label patchi : patches)
         {

src/faOptions/sources/derived/contactHeatFluxSource/contactHeatFluxSource.H

@@ -40,8 +40,6 @@ Usage
     {
         // Mandatory entries (unmodifiable)
         type                contactHeatFluxSource;
-
-        // Optional entries (unmodifiable)
         Tprimary            <TprimaryFieldName>;
 
         // Optional entries (runtime modifiable)
@@ -62,19 +60,12 @@ Usage
     \table
       Property  | Description                       | Type  | Reqd | Dflt
       type      | Type name: contactHeatFluxSource  | word  | yes  | -
+      Tprimary  | Name of primary temperature field | word  | yes  | -
       T         | Name of operand temperature field | word  | no   | T
-      Tprimary  | Name of primary temperature field | word  | no   | T
       thicknessLayers | List of thicknesses of layers | scalarList | no | -
       kappaLayers | List of conductivities of layers | scalarList | cndtnl | -
     \endtable
 
-    Fields/variables used:
-    \table
-      Property  | Description               | Type   | Deflt
-      T         | Temperature               | shell  | T
-      Tprimary  | Temperature               | volume | T
-    \endtable
-
     The inherited entries are elaborated in:
      - \link faOption.H \endlink
      - \link faceSetOption.H \endlink
@@ -133,13 +124,13 @@ class contactHeatFluxSource
 
     // Private Data
 
-        //- Name of shell temperature field (default: "T")
+        //- Name of temperature field
         word TName_;
 
-        //- Name of volume temperature field (default: "T")
-        const word TprimaryName_;
+        //- Name of primary temperature field
+        word TprimaryName_;
 
-        //- Primary (volume) region temperature
+        //- Primary region temperature
         const volScalarField& Tprimary_;
 
         //- Thickness of layers

src/faOptions/sources/derived/externalHeatFluxSource/externalHeatFluxSource.C

@@ -72,6 +72,10 @@ Foam::fa::externalHeatFluxSource::externalHeatFluxSource
     fa::faceSetOption(sourceName, modelType, dict, m, defaultAreaName),
     mode_(operationModeNames.get("mode", dict)),
     TName_(dict.getOrDefault<word>("T", "T")),
+    Q_(nullptr),
+    q_(nullptr),
+    h_(nullptr),
+    Ta_(nullptr),
     emissivity_(dict.getOrDefault<scalar>("emissivity", 0))
 {
     fieldNames_.resize(1, TName_);
@@ -201,11 +205,6 @@ bool Foam::fa::externalHeatFluxSource::read(const dictionary& dict)
 
         mode_ = operationModeNames.get("mode", dict);
 
-        Q_.reset(nullptr);
-        q_.reset(nullptr);
-        h_.reset(nullptr);
-        Ta_.reset(nullptr);
-
         switch (mode_)
         {
             case fixedPower:

src/faOptions/sources/derived/externalHeatFluxSource/externalHeatFluxSource.H

@@ -103,7 +103,7 @@ Usage
     \verbatim
       power       | Use fixed power (supply Q)
       flux        | Use fixed heat flux (supply q)
-      coefficient | Use fixes heat transfer coefficient (supply h and Ta)
+      coefficient | Use fixes heat transfer coefficient (supply h and T)
     \endverbatim
 
 See also
@@ -159,7 +159,7 @@ private:
         //- Operation mode
         operationMode mode_;
 
-        //- Name of shell temperature field (default: "T")
+        //- Name of temperature field
         word TName_;
 
         //- Heat power [W]
@@ -174,7 +174,7 @@ private:
         //- Ambient temperature [K]
         autoPtr<Function1<scalar>> Ta_;
 
-        //- Surface emissivity for radiative transfer to ambient (default: 0)
+        //- Optional surface emissivity for radiative transfer to ambient
         scalar emissivity_;
 
 

src/faOptions/sources/derived/jouleHeatingSource/jouleHeatingSource.C

@@ -42,12 +42,6 @@ namespace fa
 }
 
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-// Implementation
-#include "jouleHeatingSourceImpl.cxx"
-
-
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 Foam::fa::jouleHeatingSource::jouleHeatingSource
@@ -65,7 +59,7 @@ Foam::fa::jouleHeatingSource::jouleHeatingSource
     (
         IOobject
         (
-            suffixed(IOobject::scopedName(typeName, "V")),
+            IOobject::scopedName(typeName, "V_" + regionName_),
             regionMesh().thisDb().time().timeName(),
             regionMesh().thisDb(),
             IOobject::MUST_READ,
@@ -74,6 +68,8 @@ Foam::fa::jouleHeatingSource::jouleHeatingSource
         ),
         regionMesh()
     ),
+    scalarSigmaVsTPtr_(nullptr),
+    tensorSigmaVsTPtr_(nullptr),
     curTimeIndex_(-1),
     nIter_(1),
     anisotropicElectricalConductivity_(false)
@@ -82,8 +78,6 @@ Foam::fa::jouleHeatingSource::jouleHeatingSource
 
     fa::option::resetApplied();
 
-    read(dict);
-
     if (anisotropicElectricalConductivity_)
     {
         Info<< "    Using tensor electrical conductivity" << endl;
@@ -96,6 +90,8 @@ Foam::fa::jouleHeatingSource::jouleHeatingSource
 
         initialiseSigma(coeffs_, scalarSigmaVsTPtr_);
     }
+
+    read(dict);
 }
 
 
@@ -109,14 +105,12 @@ void Foam::fa::jouleHeatingSource::addSup
     const label fieldi
 )
 {
-    if (!isActive())
+    if (isActive())
     {
-        return;
-    }
+        DebugInfo
+            << name() << ": applying source to "
+            << eqn.psi().name() << endl;
 
-    DebugInfo<< name() << ": applying source to " << eqn.psi().name() << endl;
-
-    {
         if (curTimeIndex_ != mesh().time().timeIndex())
         {
             for (label i = 0; i < nIter_; ++i)
@@ -124,7 +118,8 @@ void Foam::fa::jouleHeatingSource::addSup
                 if (anisotropicElectricalConductivity_)
                 {
                     // Update sigma as a function of T if required
-                    const auto& sigma = updateSigma(tensorSigmaVsTPtr_);
+                    const areaTensorField& sigma =
+                        updateSigma(tensorSigmaVsTPtr_);
 
                     // Solve the electrical potential equation
                     faScalarMatrix VEqn(fam::laplacian(h*sigma, V_));
@@ -134,7 +129,8 @@ void Foam::fa::jouleHeatingSource::addSup
                 else
                 {
                     // Update sigma as a function of T if required
-                    const auto& sigma = updateSigma(scalarSigmaVsTPtr_);
+                    const areaScalarField& sigma =
+                        updateSigma(scalarSigmaVsTPtr_);
 
                     // Solve the electrical potential equation
                     faScalarMatrix VEqn(fam::laplacian(h*sigma, V_));
@@ -149,7 +145,7 @@ void Foam::fa::jouleHeatingSource::addSup
         // Add the Joule heating contribution
         const word sigmaName
         (
-            IOobject::scopedName(typeName, "sigma") + suffixHint()
+            IOobject::scopedName(typeName, "sigma_" + regionName_)
         );
 
         areaVectorField gradV("gradV", fac::grad(V_));
@@ -166,13 +162,15 @@ void Foam::fa::jouleHeatingSource::addSup
 
         if (anisotropicElectricalConductivity_)
         {
-            const auto& sigma = obr.lookupObject<areaTensorField>(sigmaName);
+            const auto& sigma =
+                obr.lookupObject<areaTensorField>(sigmaName);
 
             tsource = (h*sigma & gradV) & gradV;
         }
         else
         {
-            const auto& sigma = obr.lookupObject<areaScalarField>(sigmaName);
+            const auto& sigma =
+                obr.lookupObject<areaScalarField>(sigmaName);
 
             tsource = (h*sigma*gradV) & gradV;
         }

src/faOptions/sources/derived/jouleHeatingSource/jouleHeatingSource.H

@@ -115,30 +115,23 @@ Usage
      - \link faceSetOption.H \endlink
 
 Note
-   If the \c sigma entry is present, the electrical conductivity is specified
-   as a function of temperature using a \c Function1 type, otherwise
-   the \c sigma field will be read from file.
-   When the \c anisotropicElectricalConductivity flag is set to \c true,
-   \c sigma should be specified as a \em tensor quantity instead of as
-   an isotropic \em scalar quantity.
-
-   BREAKING Naming changes from 2056 and earlier for the fields:
-   \table
-     Field   | Scoped names              | Scoped names (old)
-     V       | \<scope\>:V (suffix)      | \<scope\>:V_ + regionName
-     sigma   | \<scope\>:sigma (suffix)  | \<scope\>:sigma_ + regionName
-   \endtable
-
-   It is possible to replicate the older naming by specifying
-   the \c suffixing to ('_' + regionName).
+  - \c anisotropicElectricalConductivity=true enables
+  anisotropic (tensorial) electrical conductivity.
+  - \c anisotropicElectricalConductivity=false enables
+  isotropic (scalar) electrical conductivity.
+  - The electrical conductivity can be specified using either:
+    - If the \c sigma entry is present the electrical conductivity is specified
+    as a function of temperature using a \c Function1 type.
+    - If not present the \c sigma field will be read from file.
+    - If the \c anisotropicElectricalConductivity flag is set to \c true,
+    \c sigma should be specified as a tensor quantity.
 
 See also
   - Foam::Function1
-  - Foam::fv::jouleHeatingSource
 
 SourceFiles
-    jouleHeatingSource.cxx
-    jouleHeatingSourceImpl.cxx
+    jouleHeatingSource.C
+    jouleHeatingSourceTemplates.C
 
 \*---------------------------------------------------------------------------*/
 
@@ -195,13 +188,13 @@ class jouleHeatingSource
         void initialiseSigma
         (
             const dictionary& dict,
-            autoPtr<Function1<Type>>& sigmaFunctionPtr
+            autoPtr<Function1<Type>>& sigmaVsTPtr
         );
 
         //- Update the electrical conductivity field
         template<class Type>
         const GeometricField<Type, faPatchField, areaMesh>&
-        updateSigma(const autoPtr<Function1<Type>>& sigmaFunctionPtr) const;
+        updateSigma(const autoPtr<Function1<Type>>& sigmaVsTPtr) const;
 
 
 public:
@@ -236,22 +229,22 @@ public:
 
     // Member Functions
 
-    // Evaluation
+        // Evaluation
 
-        //- Add explicit contribution to energy equation
-        virtual void addSup
-        (
-            const areaScalarField& h,
-            const areaScalarField& rho,
-            faMatrix<scalar>& eqn,
-            const label fieldi
-        );
+            //- Add explicit contribution to compressible momentum equation
+            virtual void addSup
+            (
+                const areaScalarField& h,
+                const areaScalarField& rho,
+                faMatrix<scalar>& eqn,
+                const label fieldi
+            );
 
 
-    // IO
+        // IO
 
-        //- Read source dictionary
-        virtual bool read(const dictionary& dict);
+            //- Read source dictionary
+            virtual bool read(const dictionary& dict);
 };
 
 
@@ -262,6 +255,12 @@ public:
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+#ifdef NoRepository
+    #include "jouleHeatingSourceTemplates.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
 #endif
 
 // ************************************************************************* //

src/faOptions/sources/derived/jouleHeatingSource/jouleHeatingSourceTemplates.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2019-2025 OpenCFD Ltd.
+    Copyright (C) 2019-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,21 +33,16 @@ template<class Type>
 void Foam::fa::jouleHeatingSource::initialiseSigma
 (
     const dictionary& dict,
-    autoPtr<Function1<Type>>& sigmaFunctionPtr
+    autoPtr<Function1<Type>>& sigmaVsTPtr
 )
 {
     typedef GeometricField<Type, faPatchField, areaMesh> FieldType;
 
-    const word sigmaName
-    (
-        IOobject::scopedName(typeName, "sigma") + suffixHint()
-    );
-
     auto& obr = regionMesh().thisDb();
 
     IOobject io
     (
-        sigmaName,
+        IOobject::scopedName(typeName, "sigma_" + regionName_),
         obr.time().timeName(),
         obr,
         IOobject::NO_READ,
@@ -57,11 +52,11 @@ void Foam::fa::jouleHeatingSource::initialiseSigma
 
     autoPtr<FieldType> tsigma;
 
-    // Is sigma defined using a Function1 type?
-    sigmaFunctionPtr = Function1<Type>::NewIfPresent("sigma", dict, &mesh_);
-
-    if (sigmaFunctionPtr)
+    if (dict.found("sigma"))
     {
+        // Sigma to be defined using a Function1 type
+        sigmaVsTPtr = Function1<Type>::New("sigma", dict, &mesh_);
+
         tsigma.reset
         (
             new FieldType
@@ -94,34 +89,31 @@ template<class Type>
 const Foam::GeometricField<Type, Foam::faPatchField, Foam::areaMesh>&
 Foam::fa::jouleHeatingSource::updateSigma
 (
-    const autoPtr<Function1<Type>>& sigmaFunctionPtr
+    const autoPtr<Function1<Type>>& sigmaVsTPtr
 ) const
 {
     typedef GeometricField<Type, faPatchField, areaMesh> FieldType;
 
-    const word sigmaName
-    (
-        IOobject::scopedName(typeName, "sigma") + suffixHint()
-    );
-
     const auto& obr = regionMesh().thisDb();
 
-    auto& sigma = obr.lookupObjectRef<FieldType>(sigmaName);
+    auto& sigma =
+        obr.lookupObjectRef<FieldType>
+        (
+            IOobject::scopedName(typeName, "sigma_" + regionName_)
+        );
 
-    if (!sigmaFunctionPtr)
+    if (!sigmaVsTPtr)
     {
         // Electrical conductivity field, sigma, was specified by the user
         return sigma;
     }
 
-    const auto& sigmaFunction = sigmaFunctionPtr();
-
     const auto& T = obr.lookupObject<areaScalarField>(TName_);
 
     // Internal field
     forAll(sigma, i)
     {
-        sigma[i] = sigmaFunction.value(T[i]);
+        sigma[i] = sigmaVsTPtr->value(T[i]);
     }
 
 
@@ -135,7 +127,7 @@ Foam::fa::jouleHeatingSource::updateSigma
             const scalarField& Tbf = T.boundaryField()[patchi];
             forAll(pf, facei)
             {
-                pf[facei] = sigmaFunction.value(Tbf[facei]);
+                pf[facei] = sigmaVsTPtr->value(Tbf[facei]);
             }
         }
     }

src/finiteArea/faMesh/faMesh.C

@@ -28,7 +28,6 @@ License
 
 #include "faMesh.H"
 #include "faMeshBoundaryHalo.H"
-#include "faMeshesRegistry.H"
 #include "faGlobalMeshData.H"
 #include "Time.H"
 #include "polyMesh.H"
@@ -160,12 +159,6 @@ const Foam::objectRegistry* Foam::faMesh::registry(const polyMesh& pMesh)
 //     return obr.cfindObject<objectRegistry>(faMesh::prefix());
 // }
 
-// Forwarding
-const Foam::objectRegistry& Foam::faMesh::Registry(const polyMesh& pMesh)
-{
-    return faMeshesRegistry::Registry(pMesh);
-}
-
 
 const Foam::faMesh& Foam::faMesh::mesh
 (

src/finiteArea/faMesh/faMesh.H

@@ -751,14 +751,10 @@ public:
 
     // Database
 
-        //- Find the singleton parent registry (on the polyMesh)
-        //- that contains all objects related to finite-area.
+        //- The parent registry containing all finite-area meshes
+        //- on the polyMesh.
         static const objectRegistry* registry(const polyMesh& pMesh);
 
-        //- Return the singleton parent registry (on the polyMesh)
-        //- that contains all objects related to finite-area.
-        static const objectRegistry& Registry(const polyMesh& pMesh);
-
         //- The single-region finite-area region on the polyMesh.
         //- Uses lookupObject semantics - Fatal if non-existent
         static const faMesh& mesh(const polyMesh& pMesh);

src/finiteArea/faMesh/faMeshRegistry.C

@@ -27,8 +27,8 @@ License
 
 #include "faMesh.H"
 #include "faMeshesRegistry.H"
-#include "polyMesh.H"
 #include "Time.H"
+#include "polyMesh.H"
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
@@ -43,7 +43,6 @@ Foam::faMeshRegistry::faMeshRegistry
         IOobject
         (
             (areaName.empty() ? polyMesh::defaultRegion : areaName),
-            mesh.thisDb().time().timeName(),
             faMeshesRegistry::New(mesh).thisDb(),
             IOobjectOption::NO_READ,
             IOobjectOption::AUTO_WRITE,

src/finiteArea/faMesh/faMeshesRegistry.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2023-2025 OpenCFD Ltd.
+    Copyright (C) 2023-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -86,8 +86,6 @@ bool Foam::faMeshesRegistry::writeObject
     const bool writeOnProc
 ) const
 {
-    // Could also restrict to faMesh only...
-    //
     // for (const faMesh& m : objects_.csorted<faMesh>())
     // {
     //     m.write(writeOnProc);

src/finiteArea/faMesh/faMeshesRegistry.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2023-2025 OpenCFD Ltd.
+    Copyright (C) 2023-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -144,34 +144,14 @@ public:
         explicit faMeshesRegistry(const polyMesh& mesh);
 
 
-    // Factory Methods
-
-        //- Return the registry of objects on the singleton.
-        //  Same as New(mesh).thisDb()
-        FOAM_NO_DANGLING_REFERENCE  //< Reference stored in registry
-        static const objectRegistry& Registry(const polyMesh& mesh)
-        {
-            return MeshObject_type::New(mesh).thisDb();
-        }
-
-
     // Database
 
-        // It redirects to the private objects but uses some
-        // objectRegistry method naming
-
-        //- The registry of the objects
+        //- Return the object registry
         const objectRegistry& thisDb() const noexcept
         {
             return objects_;
         }
 
-        //- Local relative to time
-        const fileName& dbDir() const
-        {
-            return objects_.dbDir();
-        }
-
         //- The polyMesh reference
         const polyMesh& mesh() const noexcept
         {

src/finiteVolume/finiteVolume/gradSchemes/LeastSquaresGrad/LeastSquaresGrad.C

@@ -1,4 +1,4 @@
-/*---------------------------------------------------------------------------*\
+  /*---------------------------------------------------------------------------*\
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
@@ -36,23 +36,18 @@ License
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 template<class Type, class Stencil>
-Foam::tmp
-<
-    Foam::GeometricField
-    <
-        typename Foam::outerProduct<Foam::vector, Type>::type,
-        Foam::fvPatchField,
-    Foam::volMesh
-    >
->
-Foam::fv::LeastSquaresGrad<Type, Stencil>::calcGrad
+void Foam::fv::LeastSquaresGrad<Type, Stencil>::calcGrad
 (
-    const GeometricField<Type, fvPatchField, volMesh>& vtf,
-    const word& name
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        fvPatchField,
+        volMesh
+    >& lsGrad,
+    const GeometricField<Type, fvPatchField, volMesh>& vtf
 ) const
 {
     typedef typename outerProduct<vector, Type>::type GradType;
-    typedef GeometricField<GradType, fvPatchField, volMesh> GradFieldType;
 
     const fvMesh& mesh = vtf.mesh();
 
@@ -62,24 +57,7 @@ Foam::fv::LeastSquaresGrad<Type, Stencil>::calcGrad
         mesh
     );
 
-    tmp<GradFieldType> tlsGrad
-    (
-        new GradFieldType
-        (
-            IOobject
-            (
-                name,
-                vtf.instance(),
-                mesh,
-                IOobject::NO_READ,
-                IOobject::NO_WRITE
-            ),
-            mesh,
-            dimensioned<GradType>(vtf.dimensions()/dimLength, Zero),
-            fvPatchFieldBase::extrapolatedCalculatedType()
-        )
-    );
-    GradFieldType& lsGrad = tlsGrad.ref();
+    lsGrad = dimensioned<GradType>(vtf.dimensions()/dimLength, Zero);
     Field<GradType>& lsGradIf = lsGrad;
 
     const extendedCentredCellToCellStencil& stencil = lsv.stencil();
@@ -131,6 +109,50 @@ Foam::fv::LeastSquaresGrad<Type, Stencil>::calcGrad
     // Correct the boundary conditions
     lsGrad.correctBoundaryConditions();
     gaussGrad<Type>::correctBoundaryConditions(vtf, lsGrad);
+}
+
+
+template<class Type, class Stencil>
+Foam::tmp
+<
+    Foam::GeometricField
+    <
+        typename Foam::outerProduct<Foam::vector, Type>::type,
+        Foam::fvPatchField,
+    Foam::volMesh
+    >
+>
+Foam::fv::LeastSquaresGrad<Type, Stencil>::calcGrad
+(
+    const GeometricField<Type, fvPatchField, volMesh>& vtf,
+    const word& name
+) const
+{
+    typedef typename outerProduct<vector, Type>::type GradType;
+    typedef GeometricField<GradType, fvPatchField, volMesh> GradFieldType;
+
+    const fvMesh& mesh = vtf.mesh();
+
+    tmp<GradFieldType> tlsGrad
+    (
+        new GradFieldType
+        (
+            IOobject
+            (
+                name,
+                vtf.instance(),
+                mesh,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE
+            ),
+            mesh,
+            vtf.dimensions()/dimLength,
+            fvPatchFieldBase::extrapolatedCalculatedType()
+        )
+    );
+    GradFieldType& lsGrad = tlsGrad.ref();
+
+    calcGrad(lsGrad, vtf);
 
     return tlsGrad;
 }

src/finiteVolume/finiteVolume/gradSchemes/LeastSquaresGrad/LeastSquaresGrad.H

@@ -132,6 +132,14 @@ public:
             const GeometricField<Type, fvPatchField, volMesh>& vsf,
             const word& name
         ) const;
+
+        //- Calculate the grad of the given field into supplied field
+        virtual void calcGrad
+        (
+            GeometricField
+            <typename outerProduct<vector, Type>::type, fvPatchField, volMesh>& res,
+            const GeometricField<Type, fvPatchField, volMesh>&
+        ) const;
 };
 
 

src/finiteVolume/finiteVolume/gradSchemes/fourthGrad/fourthGrad.C

@@ -38,19 +38,21 @@ License
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 template<class Type>
-Foam::tmp
-<
-    Foam::GeometricField
-    <
-        typename Foam::outerProduct<Foam::vector, Type>::type,
-        Foam::fvPatchField,
-        Foam::volMesh
-    >
->
-Foam::fv::fourthGrad<Type>::calcGrad
+void Foam::fv::fourthGrad<Type>::calcGrad
 (
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        fvPatchField,
+        volMesh
+    >& fGrad,
     const GeometricField<Type, fvPatchField, volMesh>& vsf,
-    const word& name
+    const GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        fvPatchField,
+        volMesh
+    >& secondfGrad
 ) const
 {
     // The fourth-order gradient is calculated in two passes.  First,
@@ -59,37 +61,11 @@ Foam::fv::fourthGrad<Type>::calcGrad
     // gradient to complete the accuracy.
 
     typedef typename outerProduct<vector, Type>::type GradType;
-    typedef GeometricField<GradType, fvPatchField, volMesh> GradFieldType;
 
     const fvMesh& mesh = vsf.mesh();
 
-    // Assemble the second-order least-square gradient
-    // Calculate the second-order least-square gradient
-    tmp<GradFieldType> tsecondfGrad
-      = leastSquaresGrad<Type>(mesh).grad
-        (
-            vsf,
-            "leastSquaresGrad(" + vsf.name() + ")"
-        );
-    const GradFieldType& secondfGrad =
-        tsecondfGrad();
-
-    tmp<GradFieldType> tfGrad
-    (
-        new GradFieldType
-        (
-            IOobject
-            (
-                name,
-                vsf.instance(),
-                mesh,
-                IOobject::NO_READ,
-                IOobject::NO_WRITE
-            ),
-            secondfGrad
-        )
-    );
-    GradFieldType& fGrad = tfGrad.ref();
+    // Initialise to gradient
+    fGrad = secondfGrad;
 
     const vectorField& C = mesh.C();
 
@@ -158,9 +134,102 @@ Foam::fv::fourthGrad<Type>::calcGrad
 
     fGrad.correctBoundaryConditions();
     gaussGrad<Type>::correctBoundaryConditions(vsf, fGrad);
+}
+
+
+template<class Type>
+Foam::tmp
+<
+    Foam::GeometricField
+    <
+        typename Foam::outerProduct<Foam::vector, Type>::type,
+        Foam::fvPatchField,
+        Foam::volMesh
+    >
+>
+Foam::fv::fourthGrad<Type>::calcGrad
+(
+    const GeometricField<Type, fvPatchField, volMesh>& vsf,
+    const word& name
+) const
+{
+    // The fourth-order gradient is calculated in two passes.  First,
+    // the standard least-square gradient is assembled.  Then, the
+    // fourth-order correction is added to the second-order accurate
+    // gradient to complete the accuracy.
+
+    typedef typename outerProduct<vector, Type>::type GradType;
+    typedef GeometricField<GradType, fvPatchField, volMesh> GradFieldType;
+
+    const fvMesh& mesh = vsf.mesh();
+
+    // Assemble the second-order least-square gradient
+    // Calculate the second-order least-square gradient
+    tmp<GradFieldType> tsecondfGrad
+      = leastSquaresGrad<Type>(mesh).grad
+        (
+            vsf,
+            "leastSquaresGrad(" + vsf.name() + ")"
+        );
+    const GradFieldType& secondfGrad = tsecondfGrad();
+
+    tmp<GradFieldType> tfGrad
+    (
+        new GradFieldType
+        (
+            IOobject
+            (
+                name,
+                vsf.instance(),
+                mesh,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE
+            ),
+            mesh,
+            vsf.dimensions()/dimLength,
+            fvPatchFieldBase::extrapolatedCalculatedType()
+        )
+    );
+
+    calcGrad(tfGrad.ref(), vsf, secondfGrad);
 
     return tfGrad;
 }
 
 
+template<class Type>
+void Foam::fv::fourthGrad<Type>::calcGrad
+(
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        fvPatchField,
+        volMesh
+    >& fGrad,
+    const GeometricField<Type, fvPatchField, volMesh>& vsf
+) const
+{
+    // The fourth-order gradient is calculated in two passes.  First,
+    // the standard least-square gradient is assembled.  Then, the
+    // fourth-order correction is added to the second-order accurate
+    // gradient to complete the accuracy.
+
+    typedef typename outerProduct<vector, Type>::type GradType;
+    typedef GeometricField<GradType, fvPatchField, volMesh> GradFieldType;
+
+    const fvMesh& mesh = vsf.mesh();
+
+    // Assemble the second-order least-square gradient
+    // Calculate the second-order least-square gradient
+    tmp<GradFieldType> tsecondfGrad
+      = leastSquaresGrad<Type>(mesh).grad
+        (
+            vsf,
+            "leastSquaresGrad(" + vsf.name() + ")"
+        );
+
+    calcGrad(fGrad, vsf, tsecondfGrad());
+}
+
+
 // ************************************************************************* //

src/finiteVolume/finiteVolume/gradSchemes/fourthGrad/fourthGrad.H

@@ -99,6 +99,32 @@ public:
             const GeometricField<Type, fvPatchField, volMesh>& vsf,
             const word& name
         ) const;
+
+        //- Calculate the grad of the given field into supplied field
+        virtual void calcGrad
+        (
+            GeometricField
+            <typename outerProduct<vector, Type>::type, fvPatchField, volMesh>& res,
+            const GeometricField<Type, fvPatchField, volMesh>&
+        ) const;
+
+        //- Helper : calculate the grad of the given field into supplied field
+        void calcGrad
+        (
+            GeometricField
+            <
+                typename outerProduct<vector, Type>::type,
+                fvPatchField,
+                volMesh
+            >& fGrad,
+            const GeometricField<Type, fvPatchField, volMesh>& vsf,
+            const GeometricField
+            <
+                typename outerProduct<vector, Type>::type,
+                fvPatchField,
+                volMesh
+            >& secondfGrad
+        ) const;
 };
 
 

src/finiteVolume/finiteVolume/gradSchemes/gaussGrad/gaussGrad.C

@@ -140,6 +140,67 @@ Foam::fv::gaussGrad<Type>::calcGrad
 }
 
 
+template<class Type>
+void Foam::fv::gaussGrad<Type>::calcGrad
+(
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        fvPatchField,
+        volMesh
+    >& gGrad,
+    const GeometricField<Type, fvPatchField, volMesh>& vsf
+) const
+{
+    typedef typename outerProduct<vector, Type>::type GradType;
+
+    DebugPout<< "gaussGrad<Type>::calcGrad on " << vsf.name()
+        << " into " << gGrad.name() << endl;
+
+    const fvMesh& mesh = vsf.mesh();
+    const labelUList& owner = mesh.owner();
+    const labelUList& neighbour = mesh.neighbour();
+    const vectorField& Sf = mesh.Sf();
+
+    const auto tssf(tinterpScheme_().interpolate(vsf));
+    const auto& ssf = tssf();
+
+    gGrad = dimensioned<GradType>(vsf.dimensions()/dimLength, Zero);
+
+    Field<GradType>& igGrad = gGrad;
+    const Field<Type>& issf = ssf;
+
+    forAll(owner, facei)
+    {
+        const GradType Sfssf = Sf[facei]*issf[facei];
+
+        igGrad[owner[facei]] += Sfssf;
+        igGrad[neighbour[facei]] -= Sfssf;
+    }
+
+    forAll(mesh.boundary(), patchi)
+    {
+        const labelUList& pFaceCells =
+            mesh.boundary()[patchi].faceCells();
+
+        const vectorField& pSf = mesh.Sf().boundaryField()[patchi];
+
+        const fvsPatchField<Type>& pssf = ssf.boundaryField()[patchi];
+
+        forAll(mesh.boundary()[patchi], facei)
+        {
+            igGrad[pFaceCells[facei]] += pSf[facei]*pssf[facei];
+        }
+    }
+
+    igGrad /= mesh.V();
+
+    gGrad.correctBoundaryConditions();
+
+    correctBoundaryConditions(vsf, gGrad);
+}
+
+
 template<class Type>
 void Foam::fv::gaussGrad<Type>::correctBoundaryConditions
 (

src/finiteVolume/finiteVolume/gradSchemes/gaussGrad/gaussGrad.H

@@ -145,6 +145,14 @@ public:
             const word& name
         ) const;
 
+        //- Calculate the grad of the given field into supplied field
+        virtual void calcGrad
+        (
+            GeometricField
+            <typename outerProduct<vector, Type>::type, fvPatchField, volMesh>& res,
+            const GeometricField<Type, fvPatchField, volMesh>&
+        ) const;
+
         //- Correct the boundary values of the gradient using the patchField
         //- snGrad functions
         static void correctBoundaryConditions

src/finiteVolume/finiteVolume/gradSchemes/gradScheme/gradScheme.C

@@ -96,7 +96,7 @@ Foam::fv::gradScheme<Type>::grad
     GradFieldType* pgGrad =
         mesh().objectRegistry::template getObjectPtr<GradFieldType>(name);
 
-    if (!this->mesh().cache(name) || this->mesh().changing())
+    if (!this->mesh().cache(name) || this->mesh().topoChanging())
     {
         // Delete any old occurrences to avoid double registration
         if (pgGrad && pgGrad->ownedByRegistry())
@@ -119,17 +119,14 @@ Foam::fv::gradScheme<Type>::grad
     }
     else
     {
-        if (pgGrad->upToDate(vsf))
+        if (pgGrad->upToDate(vsf) && this->mesh().upToDatePoints(*pgGrad))
         {
             solution::cachePrintMessage("Reusing", name, vsf);
         }
         else
         {
             solution::cachePrintMessage("Updating", name, vsf);
-            delete pgGrad;
-
-            pgGrad = calcGrad(vsf, name).ptr();
-            regIOobject::store(pgGrad);
+            calcGrad(*pgGrad, vsf);
         }
     }
 
@@ -180,4 +177,23 @@ Foam::fv::gradScheme<Type>::grad
 }
 
 
+template<class Type>
+void Foam::fv::gradScheme<Type>::calcGrad
+(
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        fvPatchField,
+        volMesh
+    >& result,
+    const GeometricField<Type, fvPatchField, volMesh>& vsf
+) const
+{
+    DebugPout<< "gradScheme<Type>::calcGrad on " << vsf.name()
+        << " into " << result.name() << endl;
+
+    result = calcGrad(vsf, result.name());
+}
+
+
 // ************************************************************************* //

src/finiteVolume/finiteVolume/gradSchemes/gradScheme/gradScheme.H

@@ -142,6 +142,14 @@ public:
             const word& name
         ) const = 0;
 
+        //- Calculate the grad of the given field into supplied field
+        virtual void calcGrad
+        (
+            GeometricField
+            <typename outerProduct<vector, Type>::type, fvPatchField, volMesh>& res,
+            const GeometricField<Type, fvPatchField, volMesh>&
+        ) const;
+
         //- Calculate and return the grad of the given field
         //- which may have been cached
         tmp

src/finiteVolume/finiteVolume/gradSchemes/limitedGradSchemes/cellLimitedGrad/cellLimitedGrad.C

@@ -62,40 +62,25 @@ void Foam::fv::cellLimitedGrad<Type, Limiter>::limitGradient
 
 
 template<class Type, class Limiter>
-Foam::tmp
-<
-    Foam::GeometricField
-    <
-        typename Foam::outerProduct<Foam::vector, Type>::type,
-        Foam::fvPatchField,
-        Foam::volMesh
-    >
->
-Foam::fv::cellLimitedGrad<Type, Limiter>::calcGrad
+void Foam::fv::cellLimitedGrad<Type, Limiter>::calcGrad
 (
-    const GeometricField<Type, fvPatchField, volMesh>& vsf,
-    const word& name
-) const
-{
-    const fvMesh& mesh = vsf.mesh();
-
-    tmp
-    <
-        GeometricField
-        <typename outerProduct<vector, Type>::type, fvPatchField, volMesh>
-    > tGrad = basicGradScheme_().calcGrad(vsf, name);
-
-    if (k_ < SMALL)
-    {
-        return tGrad;
-    }
-
     GeometricField
     <
         typename outerProduct<vector, Type>::type,
         fvPatchField,
         volMesh
-    >& g = tGrad.ref();
+    >& g,
+    const GeometricField<Type, fvPatchField, volMesh>& vsf
+) const
+{
+    const fvMesh& mesh = vsf.mesh();
+
+    basicGradScheme_().calcGrad(g, vsf);
+
+    if (k_ < SMALL)
+    {
+        return;
+    }
 
     const labelUList& owner = mesh.owner();
     const labelUList& neighbour = mesh.neighbour();
@@ -227,6 +212,49 @@ Foam::fv::cellLimitedGrad<Type, Limiter>::calcGrad
     limitGradient(limiter, g);
     g.correctBoundaryConditions();
     gaussGrad<Type>::correctBoundaryConditions(vsf, g);
+}
+
+
+template<class Type, class Limiter>
+Foam::tmp
+<
+    Foam::GeometricField
+    <
+        typename Foam::outerProduct<Foam::vector, Type>::type,
+        Foam::fvPatchField,
+        Foam::volMesh
+    >
+>
+Foam::fv::cellLimitedGrad<Type, Limiter>::calcGrad
+(
+    const GeometricField<Type, fvPatchField, volMesh>& vsf,
+    const word& name
+) const
+{
+    typedef typename outerProduct<vector, Type>::type GradType;
+    typedef GeometricField<GradType, fvPatchField, volMesh> GradFieldType;
+
+    const fvMesh& mesh = vsf.mesh();
+
+    tmp<GradFieldType> tGrad
+    (
+        new GradFieldType
+        (
+            IOobject
+            (
+                name,
+                vsf.instance(),
+                mesh,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE
+            ),
+            mesh,
+            vsf.dimensions()/dimLength,
+            fvPatchFieldBase::extrapolatedCalculatedType()
+        )
+    );
+    
+    calcGrad(tGrad.ref(), vsf);
 
     return tGrad;
 }

src/finiteVolume/finiteVolume/gradSchemes/limitedGradSchemes/cellLimitedGrad/cellLimitedGrad.H

@@ -150,6 +150,14 @@ public:
             const GeometricField<Type, fvPatchField, volMesh>& vsf,
             const word& name
         ) const;
+
+        //- Calculate the grad of the given field into supplied field
+        virtual void calcGrad
+        (
+            GeometricField
+            <typename outerProduct<vector, Type>::type, fvPatchField, volMesh>& res,
+            const GeometricField<Type, fvPatchField, volMesh>&
+        ) const;
 };
 
 

src/finiteVolume/fvMatrices/fvMatrix/fvMatrix.C

@@ -2984,6 +2984,77 @@ Foam::Ostream& Foam::operator<<(Ostream& os, const fvMatrix<Type>& fvm)
 }
 
 
+// * * * * * * * * * * * * * Expression Templates  * * * * * * * * * * * * * //
+
+template<class Type>
+template<typename E>
+Foam::fvMatrix<Type>::fvMatrix
+(
+    const GeometricField<Type, fvPatchField, volMesh>& psi,
+    const Expression::fvMatrixExpression
+    <
+        E,
+        typename E::DiagExpr,
+        typename E::UpperExpr,
+        typename E::LowerExpr,
+        typename E::FaceFluxExpr,
+        typename E::SourceExpr
+   >& expr
+)
+:
+    lduMatrix(psi.mesh()),
+    psi_(psi),
+    useImplicit_(false),
+    lduAssemblyName_(),
+    nMatrix_(0),
+    dimensions_(expr.dimensions()),
+    source_(psi.size(), Zero),
+    internalCoeffs_(psi.mesh().boundary().size()),
+    boundaryCoeffs_(psi.mesh().boundary().size())
+{
+    DebugInFunction
+        << "Constructing fvMatrix<Type> from expression for field "
+        << psi_.name() << endl;
+
+    checkImplicit();
+
+    // Fill in diag,upper,lower etc.
+    expr.evaluate(*this);
+
+    auto& psiRef = this->psi(0);
+    const label currentStatePsi = psiRef.eventNo();
+    psiRef.boundaryFieldRef().updateCoeffs();
+    psiRef.eventNo() = currentStatePsi;
+}
+
+
+template<class Type>
+Foam::Expression::fvMatrixConstRefWrap<Foam::fvMatrix<Type>>
+Foam::fvMatrix<Type>::expr() const
+{
+    return Expression::fvMatrixConstRefWrap<Foam::fvMatrix<Type>>(*this);
+}
+
+
+template<class Type>
+template<typename E>
+void Foam::fvMatrix<Type>::operator=
+(
+    const Expression::fvMatrixExpression
+    <
+        E,
+        typename E::DiagExpr,
+        typename E::UpperExpr,
+        typename E::LowerExpr,
+        typename E::FaceFluxExpr,
+        typename E::SourceExpr
+   >& expr
+)
+{
+    expr.evaluate(*this);
+}
+
+
 // * * * * * * * * * * * * * * * * Solvers * * * * * * * * * * * * * * * * * //
 
 #include "fvMatrixSolve.C"

src/finiteVolume/fvMatrices/fvMatrix/fvMatrix.H

@@ -53,6 +53,8 @@ SourceFiles
 #include "lduPrimitiveMeshAssembly.H"
 #include "lduMesh.H"
 
+#include "fvMatrixExpression.H"
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 namespace Foam
@@ -741,6 +743,47 @@ public:
             Ostream&,
             const fvMatrix<Type>&
         );
+
+
+    // Expression templates
+
+        //- Construct given a field to solve for and expressions for
+        //- all the components
+        template<typename E>
+        fvMatrix
+        (
+            const GeometricField<Type, fvPatchField, volMesh>& psi,
+            const Expression::fvMatrixExpression
+            <
+                E,
+                typename E::DiagExpr,
+                typename E::UpperExpr,
+                typename E::LowerExpr,
+                typename E::FaceFluxExpr,
+                typename E::SourceExpr
+           >& expr
+        );
+
+        //- Wrap value as expression
+        typename Expression::fvMatrixConstRefWrap
+        <
+            fvMatrix<Type>
+        > expr() const;
+
+        //- Assign values from expression
+        template<typename E>
+        void operator=
+        (
+            const Expression::fvMatrixExpression
+            <
+                E,
+                typename E::DiagExpr,
+                typename E::UpperExpr,
+                typename E::LowerExpr,
+                typename E::FaceFluxExpr,
+                typename E::SourceExpr
+           >& expr
+       );
 };
 
 

src/fused/finiteVolume/fusedGaussGrad.C

@@ -226,6 +226,94 @@ Foam::fv::fusedGaussGrad<Type>::calcGrad
 }
 
 
+template<class Type>
+void Foam::fv::fusedGaussGrad<Type>::calcGrad
+(
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        fvPatchField,
+        volMesh
+    >& gGrad,
+    const GeometricField<Type, fvPatchField, volMesh>& vf
+) const
+{
+    typedef typename outerProduct<vector, Type>::type GradType;
+
+    const fvMesh& mesh = vf.mesh();
+
+    DebugPout<< "fusedGaussGrad<Type>::calcGrad on " << vf.name()
+        << " into " << gGrad.name() << endl;
+
+    gGrad = dimensioned<GradType>(vf.dimensions()/dimLength, Zero);
+
+    if (this->tinterpScheme_().corrected())
+    {
+        const auto tfaceCorr(this->tinterpScheme_().correction(vf));
+        auto& faceCorr = tfaceCorr();
+
+        DebugPout<< "fusedGaussGrad<Type>::calcGrad corrected interpScheme "
+            << this->tinterpScheme_().type() << endl;
+
+        const auto interpolate = [&]
+        (
+            const vector& area,
+            const scalar lambda,
+
+            const Type& ownVal,
+            const Type& neiVal,
+
+            const Type& correction
+
+        ) -> GradType
+        {
+            return area*((lambda*(ownVal - neiVal) + neiVal) + correction);
+        };
+
+        fvc::surfaceSum
+        (
+            this->tinterpScheme_().weights(vf),
+            vf,
+            faceCorr,
+            interpolate,
+            gGrad,
+            false
+        );
+    }
+    else
+    {
+        DebugPout<< "fusedGaussGrad<Type>::calcGrad uncorrected interpScheme "
+            << this->tinterpScheme_().type() << endl;
+
+        const auto interpolate = [&]
+        (
+            const vector& area,
+            const scalar lambda,
+            const Type& ownVal,
+            const Type& neiVal
+        ) -> GradType
+        {
+            return area*(lambda*(ownVal - neiVal) + neiVal);
+        };
+
+        fvc::surfaceSum
+        (
+            tinterpScheme_().weights(vf),
+            vf,
+            interpolate,
+            gGrad,
+            false
+        );
+    }
+
+    gGrad.primitiveFieldRef() /= mesh.V();
+
+    gGrad.correctBoundaryConditions();
+
+    correctBoundaryConditions(vf, gGrad);
+}
+
+
 template<class Type>
 template<class GradType>
 void Foam::fv::fusedGaussGrad<Type>::correctBoundaryConditions

src/fused/finiteVolume/fusedGaussGrad.H

@@ -145,6 +145,14 @@ public:
             const word& name
         ) const;
 
+        //- Calculate the grad of the given field into supplied field
+        virtual void calcGrad
+        (
+            GeometricField
+            <typename outerProduct<vector, Type>::type, fvPatchField, volMesh>& res,
+            const GeometricField<Type, fvPatchField, volMesh>&
+        ) const;
+
         //- Correct the boundary values of the gradient using the patchField
         //- snGrad functions
         template<class GradType>

src/fused/finiteVolume/fusedGaussLaplacianScheme.C

@@ -45,6 +45,87 @@ namespace fv
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+template<class Type, class GType>
+template<class E1, class E2>
+void fusedGaussLaplacianScheme<Type, GType>::fvmCorrection
+(
+    fvMatrix<Type>& fvm,
+    const dimensionSet& gammaDim,
+    const E1& gammaMagSf,
+    const E2& corr
+)
+{
+    typedef GeometricField<Type, fvsPatchField, surfaceMesh> surfaceType;
+
+    const auto& vf = fvm.psi();
+    const fvMesh& mesh = vf.mesh();
+    const auto V = mesh.V().expr();
+
+    if (mesh.fluxRequired(vf.name()))
+    {
+        fvm.faceFluxCorrectionPtr() = std::make_unique<surfaceType>
+        (
+            IOobject
+            (
+                "faceFluxCorr",
+                mesh.time().timeName(),
+                mesh,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                IOobject::NO_REGISTER
+            ),
+            mesh,
+            gammaDim
+           *mesh.magSf().dimensions()
+           *corr.data().dimensions()
+        );
+        auto& faceFluxCorr = *fvm.faceFluxCorrectionPtr();
+
+        faceFluxCorr = corr*gammaMagSf;
+
+        fvm.source() =
+            fvm.source().expr()
+          - (
+                fvc::div
+                (
+                    faceFluxCorr
+                )().primitiveField().expr()
+               *V
+            );
+    }
+    else
+    {
+        surfaceType faceFluxCorr
+        (
+            IOobject
+            (
+                "faceFluxCorr",
+                mesh.time().timeName(),
+                mesh,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                IOobject::NO_REGISTER
+            ),
+            mesh,
+            gammaDim
+           *mesh.magSf().dimensions()
+           *corr.data().dimensions()
+        );
+        faceFluxCorr = corr*gammaMagSf;
+
+        fvm.source() =
+            fvm.source().expr()
+          - (
+                fvc::div
+                (
+                    faceFluxCorr
+                )().primitiveField().expr()
+               *V
+            );
+    }
+}
+
+
 template<class Type, class GType>
 tmp<fvMatrix<Type>>
 fusedGaussLaplacianScheme<Type, GType>::fvmLaplacianUncorrected

src/fused/finiteVolume/fusedGaussLaplacianScheme.H

@@ -65,6 +65,17 @@ class fusedGaussLaplacianScheme
 {
     // Private Member Functions
 
+        //- Helper for calculate source correction. Partially expression
+        //  templated. Move to fvMatrixExpression.H?
+        template<class E1, class E2>
+        static void fvmCorrection
+        (
+            fvMatrix<Type>& fvm,
+            const dimensionSet& gammaDim,
+            const E1& gammaMagSf,
+            const E2& corr
+        );
+
         //- See gaussLaplacianScheme
         tmp<GeometricField<Type, fvsPatchField, surfaceMesh>> gammaSnGradCorr
         (
@@ -198,6 +209,8 @@ defineFvmLaplacianScalarGamma(sphericalTensor);
 defineFvmLaplacianScalarGamma(symmTensor);
 defineFvmLaplacianScalarGamma(tensor);
 
+#undef defineFvmLaplacianScalarGamma
+
 // Unweighted laplacian
 template<>
 tmp<GeometricField<scalar, fvPatchField, volMesh>>
@@ -227,20 +240,6 @@ fusedGaussLaplacianScheme<vector, scalar>::fvcLaplacian
     const GeometricField<scalar, fvPatchField, volMesh>&,
     const GeometricField<vector, fvPatchField, volMesh>&
 );
-template<>
-tmp<fvMatrix<scalar>>
-fusedGaussLaplacianScheme<scalar, scalar>::fvmLaplacian
-(
-    const GeometricField<scalar, fvPatchField, volMesh>&,
-    const GeometricField<scalar, fvPatchField, volMesh>&
-);
-template<>
-tmp<fvMatrix<vector>>
-fusedGaussLaplacianScheme<vector, scalar>::fvmLaplacian
-(
-    const GeometricField<scalar, fvPatchField, volMesh>&,
-    const GeometricField<vector, fvPatchField, volMesh>&
-);
 
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

src/fused/finiteVolume/fusedGaussLaplacianSchemes.C

@@ -28,6 +28,7 @@ License
 
 #include "fusedGaussLaplacianScheme.H"
 #include "fvMesh.H"
+#include "fvMatrixExpression.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -40,61 +41,81 @@ Foam::tmp<Foam::fvMatrix<Foam::Type>>                                          \
 Foam::fv::fusedGaussLaplacianScheme<Foam::Type, Foam::scalar>::                \
 fvmLaplacian                                                                   \
 (                                                                              \
-    const GeometricField<scalar, fvsPatchField, surfaceMesh>& gamma,           \
+    const GeometricField<scalar, fvPatchField, volMesh>& gamma,                \
     const GeometricField<Type, fvPatchField, volMesh>& vf                      \
 )                                                                              \
 {                                                                              \
     DebugPout<< "fusedGaussLaplacianScheme::fvmLaplacian on " << vf.name()     \
-        << " with scalar gamma " << gamma.name() << endl;                      \
+        << " with scalar gamma " << gamma.name() << " and ET" << endl;         \
                                                                                \
     const fvMesh& mesh = this->mesh();                                         \
                                                                                \
-    GeometricField<scalar, fvsPatchField, surfaceMesh> gammaMagSf              \
-    (                                                                          \
-        gamma*mesh.magSf()                                                     \
-    );                                                                         \
+    const auto weights = this->tinterpGammaScheme_().weights(gamma).expr();    \
+    const auto gammaMagSf =                                                    \
+        Expression::interpolate(gamma.expr(), weights, mesh)                   \
+      * mesh.magSf().expr();                                                   \
+    /* For compatibility with linearInterpolate : avoid orientation. TBD. */   \
+    const_cast<orientedType&>(gammaMagSf.oriented()).setOriented(false);       \
+    const auto deltaCoeffs = this->tsnGradScheme_().deltaCoeffs(vf).expr();    \
                                                                                \
-    tmp<fvMatrix<Type>> tfvm = fvmLaplacianUncorrected                         \
+    tmp<fvMatrix<Type>> tfvm                                                   \
     (                                                                          \
-        gammaMagSf,                                                            \
-        this->tsnGradScheme_().deltaCoeffs(vf),                                \
-        vf                                                                     \
+        new fvMatrix<Type>                                                     \
+        (                                                                      \
+            vf,                                                                \
+            gamma.dimensions()*mesh.magSf().dimensions()*vf.dimensions()       \
+        )                                                                      \
     );                                                                         \
     fvMatrix<Type>& fvm = tfvm.ref();                                          \
                                                                                \
+    Expression::fvmLaplacianUncorrected(fvm, gammaMagSf, deltaCoeffs);         \
+                                                                               \
     if (this->tsnGradScheme_().corrected())                                    \
     {                                                                          \
-        if (mesh.fluxRequired(vf.name()))                                      \
-        {                                                                      \
-            fvm.faceFluxCorrectionPtr() = std::make_unique                     \
-            <                                                                  \
-                GeometricField<Type, fvsPatchField, surfaceMesh>               \
-            >                                                                  \
-            (                                                                  \
-                gammaMagSf*this->tsnGradScheme_().correction(vf)               \
-            );                                                                 \
-                                                                               \
-            fvm.source() -=                                                    \
-                mesh.V()*                                                      \
-                fvc::div                                                       \
-                (                                                              \
-                    *fvm.faceFluxCorrectionPtr()                               \
-                )().primitiveField();                                          \
-        }                                                                      \
-        else                                                                   \
-        {                                                                      \
-            fvm.source() -=                                                    \
-                mesh.V()*                                                      \
-                fvc::div                                                       \
-                (                                                              \
-                    gammaMagSf*this->tsnGradScheme_().correction(vf)           \
-                )().primitiveField();                                          \
-        }                                                                      \
+        const auto corr(this->tsnGradScheme_().correction(vf).expr());         \
+        fvmCorrection(fvm, gamma.dimensions(), gammaMagSf, corr);              \
     }                                                                          \
                                                                                \
     return tfvm;                                                               \
 }                                                                              \
                                                                                \
+template<>                                                                     \
+Foam::tmp<Foam::fvMatrix<Foam::Type>>                                          \
+Foam::fv::fusedGaussLaplacianScheme<Foam::Type, Foam::scalar>::                \
+fvmLaplacian                                                                   \
+(                                                                              \
+    const GeometricField<scalar, fvsPatchField, surfaceMesh>& gamma,           \
+    const GeometricField<Type, fvPatchField, volMesh>& vf                      \
+)                                                                              \
+{                                                                              \
+    DebugPout<< "fusedGaussLaplacianScheme::fvmLaplacian on " << vf.name()     \
+        << " with interpolated gamma " << gamma.name() << " and ET" << endl;   \
+                                                                               \
+    const fvMesh& mesh = this->mesh();                                         \
+                                                                               \
+    const auto gammaMagSf = gamma.expr()* mesh.magSf().expr();                 \
+    const auto deltaCoeffs = this->tsnGradScheme_().deltaCoeffs(vf).expr();    \
+                                                                               \
+    tmp<fvMatrix<Type>> tfvm                                                   \
+    (                                                                          \
+        new fvMatrix<Type>                                                     \
+        (                                                                      \
+            vf,                                                                \
+            gamma.dimensions()*mesh.magSf().dimensions()*vf.dimensions()       \
+        )                                                                      \
+    );                                                                         \
+    fvMatrix<Type>& fvm = tfvm.ref();                                          \
+                                                                               \
+    Expression::fvmLaplacianUncorrected(fvm, gammaMagSf, deltaCoeffs);         \
+                                                                               \
+    if (this->tsnGradScheme_().corrected())                                    \
+    {                                                                          \
+        const auto corr(this->tsnGradScheme_().correction(vf).expr());         \
+        fvmCorrection(fvm, gamma.dimensions(), gammaMagSf, corr);              \
+    }                                                                          \
+                                                                               \
+    return tfvm;                                                               \
+}                                                                              \
                                                                                \
 template<>                                                                     \
 Foam::tmp<Foam::GeometricField<Foam::Type, Foam::fvPatchField, Foam::volMesh>> \
@@ -500,38 +521,6 @@ Foam::fv::fusedGaussLaplacianScheme<Foam::vector, Foam::scalar>::fvcLaplacian
 }
 
 
-template<>
-Foam::tmp<Foam::fvMatrix<Foam::scalar>>
-Foam::fv::fusedGaussLaplacianScheme<Foam::scalar, Foam::scalar>::fvmLaplacian
-(
-    const GeometricField<scalar, fvPatchField, volMesh>& gamma,
-    const GeometricField<scalar, fvPatchField, volMesh>& vf
-)
-{
-    // TBD
-    DebugPout
-        << "fusedGaussLaplacianScheme<scalar, scalar>::fvmLaplacian"
-        << " on " << vf.name() << " with gamma " << gamma.name() << endl;
-    return fvmLaplacian(this->tinterpGammaScheme_().interpolate(gamma)(), vf);
-}
-
-
-template<>
-Foam::tmp<Foam::fvMatrix<Foam::vector>>
-Foam::fv::fusedGaussLaplacianScheme<Foam::vector, Foam::scalar>::fvmLaplacian
-(
-    const GeometricField<scalar, fvPatchField, volMesh>& gamma,
-    const GeometricField<vector, fvPatchField, volMesh>& vf
-)
-{
-    // TBD
-    DebugPout
-        << "fusedGaussLaplacianScheme<vector, scalar>::fvmLaplacian"
-        << " on " << vf.name() << " with gamma " << gamma.name() << endl;
-    return fvmLaplacian(this->tinterpGammaScheme_().interpolate(gamma)(), vf);
-}
-
-
 template<>
 Foam::tmp
 <

src/fvOptions/Make/files

@@ -14,7 +14,7 @@ $(derivedSources)/buoyancyEnergy/buoyancyEnergy.C
 $(derivedSources)/buoyancyForce/buoyancyForce.C
 $(derivedSources)/directionalPressureGradientExplicitSource/directionalPressureGradientExplicitSource.C
 $(derivedSources)/explicitPorositySource/explicitPorositySource.C
-$(derivedSources)/jouleHeatingSource/jouleHeatingSource.cxx
+$(derivedSources)/jouleHeatingSource/jouleHeatingSource.C
 $(derivedSources)/meanVelocityForce/meanVelocityForce.C
 $(derivedSources)/meanVelocityForce/patchMeanVelocityForce/patchMeanVelocityForce.C
 $(derivedSources)/multiphaseStabilizedTurbulence/multiphaseStabilizedTurbulence.C

src/fvOptions/sources/derived/jouleHeatingSource/jouleHeatingSource.C

@@ -29,6 +29,7 @@ License
 #include "fvMatrices.H"
 #include "fvmLaplacian.H"
 #include "fvcGrad.H"
+#include "zeroGradientFvPatchField.H"
 #include "basicThermo.H"
 #include "addToRunTimeSelectionTable.H"
 
@@ -44,12 +45,6 @@ namespace fv
 }
 
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-// Implementation
-#include "jouleHeatingSourceImpl.cxx"
-
-
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
 Foam::tmp<Foam::volSymmTensorField>
@@ -120,8 +115,11 @@ Foam::fv::jouleHeatingSource::jouleHeatingSource
         ),
         mesh
     ),
-    curTimeIndex_(-1),
-    anisotropicElectricalConductivity_(false)
+    anisotropicElectricalConductivity_(false),
+    scalarSigmaVsTPtr_(nullptr),
+    vectorSigmaVsTPtr_(nullptr),
+    csysPtr_(nullptr),
+    curTimeIndex_(-1)
 {
     // Set the field name to that of the energy
     // field from which the temperature is obtained
@@ -164,7 +162,7 @@ void Foam::fv::jouleHeatingSource::addSup
         else
         {
             // Update sigma as a function of T if required
-            const auto& sigma = updateSigma(scalarSigmaVsTPtr_);
+            const volScalarField& sigma = updateSigma(scalarSigmaVsTPtr_);
 
             // Solve the electrical potential equation
             fvScalarMatrix VEqn(fvm::laplacian(sigma, V_));
@@ -228,7 +226,7 @@ bool Foam::fv::jouleHeatingSource::read(const dictionary& dict)
 
             initialiseSigma(coeffs_, scalarSigmaVsTPtr_);
 
-            csysPtr_.reset(nullptr);  // Do not need coordinate system
+            csysPtr_.clear();  // Do not need coordinate system
         }
 
         return true;

src/fvOptions/sources/derived/jouleHeatingSource/jouleHeatingSource.H

@@ -137,28 +137,25 @@ Note
   anisotropic (vectorial) electrical conductivity.
   - \c anisotropicElectricalConductivity=false enables
   isotropic (scalar) electrical conductivity.
-
-  The electrical conductivity can be specified using either:
+  - The electrical conductivity can be specified using either:
     - If the \c sigma entry is present the electrical conductivity is specified
     as a function of temperature using a \c Function1 type.
     - If not present the \c sigma field will be read from file.
     - If the \c anisotropicElectricalConductivity flag is set to \c true,
     \c sigma should be specified as a vector quantity.
-  .
 
 See also
   - Foam::Function1
   - Foam::coordSystem
-  - Foam::fa::jouleHeatingSource
 
 SourceFiles
-    jouleHeatingSource.cxx
-    jouleHeatingSourceImpl.cxx
+    jouleHeatingSource.C
+    jouleHeatingSourceTemplates.C
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef Foam_fv_jouleHeatingSource_H
-#define Foam_fv_jouleHeatingSource_H
+#ifndef fv_jouleHeatingSource_H
+#define fv_jouleHeatingSource_H
 
 #include "fvOption.H"
 #include "Function1.H"
@@ -188,6 +185,9 @@ class jouleHeatingSource
         //- Electrical potential field / [V]
         volScalarField V_;
 
+        //- Flag to indicate that the electrical conductivity is anisotropic
+        bool anisotropicElectricalConductivity_;
+
         //- Electrical conductivity as a scalar function of temperature
         autoPtr<Function1<scalar>> scalarSigmaVsTPtr_;
 
@@ -200,9 +200,6 @@ class jouleHeatingSource
         //- Current time index (used for updating)
         label curTimeIndex_;
 
-        //- Flag to indicate that the electrical conductivity is anisotropic
-        bool anisotropicElectricalConductivity_;
-
 
     // Private Member Functions
 
@@ -217,13 +214,13 @@ class jouleHeatingSource
         void initialiseSigma
         (
             const dictionary& dict,
-            autoPtr<Function1<Type>>& sigmaFunctionPtr
+            autoPtr<Function1<Type>>& sigmaVsTPtr
         );
 
         //- Update the electrical conductivity field
         template<class Type>
         const GeometricField<Type, fvPatchField, volMesh>&
-        updateSigma(const autoPtr<Function1<Type>>& sigmaFunctionPtr) const;
+        updateSigma(const autoPtr<Function1<Type>>& sigmaVsTPtr) const;
 
 
 public:
@@ -256,21 +253,21 @@ public:
 
     // Member Functions
 
-    // Evaluation
+        // Evaluation
 
-        //- Add explicit contribution to energy equation
-        virtual void addSup
-        (
-            const volScalarField& rho,
-            fvMatrix<scalar>& eqn,
-            const label fieldi
-        );
+            //- Add explicit contribution to compressible momentum equation
+            virtual void addSup
+            (
+                const volScalarField& rho,
+                fvMatrix<scalar>& eqn,
+                const label fieldi
+            );
 
 
-    // IO
+        // IO
 
-        //- Read source dictionary
-        virtual bool read(const dictionary& dict);
+            //- Read source dictionary
+            virtual bool read(const dictionary& dict);
 };
 
 
@@ -281,6 +278,12 @@ public:
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+#ifdef NoRepository
+    #include "jouleHeatingSourceTemplates.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
 #endif
 
 // ************************************************************************* //

src/fvOptions/sources/derived/jouleHeatingSource/jouleHeatingSourceTemplates.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2016-2025 OpenCFD Ltd.
+    Copyright (C) 2016-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -27,25 +27,18 @@ License
 
 #include "emptyFvPatchField.H"
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
 template<class Type>
 void Foam::fv::jouleHeatingSource::initialiseSigma
 (
     const dictionary& dict,
-    autoPtr<Function1<Type>>& sigmaFunctionPtr
+    autoPtr<Function1<Type>>& sigmaVsTPtr
 )
 {
     typedef GeometricField<Type, fvPatchField, volMesh> FieldType;
 
-    const word sigmaName
-    (
-        IOobject::scopedName(typeName, "sigma")
-    );
-
     IOobject io
     (
-        sigmaName,
+        IOobject::scopedName(typeName, "sigma"),
         mesh_.time().timeName(),
         mesh_.thisDb(),
         IOobject::NO_READ,
@@ -55,11 +48,11 @@ void Foam::fv::jouleHeatingSource::initialiseSigma
 
     autoPtr<FieldType> tsigma;
 
-    // Is sigma defined using a Function1 ?
-    sigmaFunctionPtr = Function1<Type>::NewIfPresent("sigma", dict, &mesh_);
-
-    if (sigmaFunctionPtr)
+    if (dict.found("sigma"))
     {
+        // Sigma to be defined using a Function1 type
+        sigmaVsTPtr = Function1<Type>::New("sigma", dict, &mesh_);
+
         tsigma.reset
         (
             new FieldType
@@ -92,32 +85,28 @@ template<class Type>
 const Foam::GeometricField<Type, Foam::fvPatchField, Foam::volMesh>&
 Foam::fv::jouleHeatingSource::updateSigma
 (
-    const autoPtr<Function1<Type>>& sigmaFunctionPtr
+    const autoPtr<Function1<Type>>& sigmaVsTPtr
 ) const
 {
     typedef GeometricField<Type, fvPatchField, volMesh> FieldType;
 
-    const word sigmaName
+    auto& sigma = mesh_.lookupObjectRef<FieldType>
     (
         IOobject::scopedName(typeName, "sigma")
     );
 
-    auto& sigma = mesh_.lookupObjectRef<FieldType>(sigmaName);
-
-    if (!sigmaFunctionPtr)
+    if (!sigmaVsTPtr)
     {
         // Electrical conductivity field, sigma, was specified by the user
         return sigma;
     }
 
-    const auto& sigmaFunction = sigmaFunctionPtr();
-
     const auto& T = mesh_.lookupObject<volScalarField>(TName_);
 
     // Internal field
     forAll(sigma, i)
     {
-        sigma[i] = sigmaFunction.value(T[i]);
+        sigma[i] = sigmaVsTPtr->value(T[i]);
     }
 
 
@@ -131,7 +120,7 @@ Foam::fv::jouleHeatingSource::updateSigma
             const scalarField& Tbf = T.boundaryField()[patchi];
             forAll(pf, facei)
             {
-                pf[facei] = sigmaFunction.value(Tbf[facei]);
+                pf[facei] = sigmaVsTPtr->value(Tbf[facei]);
             }
         }
     }

src/parallel/reconstruct/faReconstruct/faMeshReconstructor.cxx

@@ -480,7 +480,6 @@ void Foam::faMeshReconstructor::createMesh()
     (
         new faMesh
         (
-            procMesh_.name(),
             *serialVolMesh_,
             identity(singlePatchFaces_.size())  // faceLabels
         )

src/regionFaModels/KirchhoffShell/KirchhoffShell.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2019-2025 OpenCFD Ltd.
+    Copyright (C) 2019-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -144,23 +144,11 @@ KirchhoffShell::KirchhoffShell
 )
 :
     vibrationShellModel(modelType, mesh, dict),
-    h_
-    (
-        IOobject
-        (
-            dict.getOrDefault<word>("h", suffixed("hs")),
-            regionMesh().time().timeName(),
-            regionMesh().thisDb(),
-            IOobject::MUST_READ,
-            IOobject::AUTO_WRITE
-        ),
-        regionMesh()
-    ),
     ps_
     (
         IOobject
         (
-            dict.getOrDefault<word>("ps", suffixed("ps")),
+            "ps_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::READ_IF_PRESENT,
@@ -169,11 +157,23 @@ KirchhoffShell::KirchhoffShell
         regionMesh(),
         dimensionedScalar(dimPressure, Zero)
     ),
+    h_
+    (
+        IOobject
+        (
+            "h_" + regionName_,
+            regionMesh().time().timeName(),
+            regionMesh().thisDb(),
+            IOobject::MUST_READ,
+            IOobject::AUTO_WRITE
+        ),
+        regionMesh()
+    ),
     laplaceW_
     (
         IOobject
         (
-            suffixed("laplaceW"),
+            "laplaceW_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::NO_READ,
@@ -186,7 +186,7 @@ KirchhoffShell::KirchhoffShell
     (
         IOobject
         (
-            suffixed("laplace2W"),
+            "laplace2W_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::NO_READ,
@@ -199,7 +199,7 @@ KirchhoffShell::KirchhoffShell
     (
         IOobject
         (
-            suffixed("w0"),
+            "w0_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::NO_READ,
@@ -212,7 +212,7 @@ KirchhoffShell::KirchhoffShell
     (
         IOobject
         (
-            suffixed("w00"),
+            "w00_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::NO_READ,
@@ -225,7 +225,7 @@ KirchhoffShell::KirchhoffShell
     (
         IOobject
         (
-            suffixed("laplaceW0"),
+            "laplaceW0_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::NO_READ,
@@ -238,7 +238,7 @@ KirchhoffShell::KirchhoffShell
     (
         IOobject
         (
-            suffixed("laplace2W0"),
+            "laplace2W0_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::NO_READ,
@@ -256,7 +256,6 @@ KirchhoffShell::KirchhoffShell
     init(dict);
 }
 
-
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
 void KirchhoffShell::preEvolveRegion()

src/regionFaModels/KirchhoffShell/KirchhoffShell.H

@@ -24,7 +24,7 @@ License
     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
 Class
-    Foam::regionModels::KirchhoffShell (Foam::regionFaModels)
+    Foam::regionFaModels::KirchhoffShell
 
 Description
     Vibration-shell finite-area model.
@@ -51,25 +51,9 @@ Usage
     \table
       Property   | Description                         | Type  | Reqd | Deflt
       vibrationShellModel | Type name: KirchhoffShell  | word  | yes  | -
-      f0         | Damping coefficient [1/s]       | scalar | yes | -
-      f1         | Damping coefficient [1/s]       | scalar | yes | -
-      f2         | Damping coefficient [1/s]       | scalar | yes | -
-      h          | Name of thickness field         | word  | no   | hs (suffix)
-      ps         | Name of pressure field          | word  | no   | ps (suffix)
-    \endtable
-
-    Fields/variables used:
-    \table
-      Property  | Description               | Type  | Deflt
-      h         | Thickness                 | shell | hs (suffix)
-      ps        | Pressure on shell         | shell | ps (suffix)
-    \endtable
-
-    Naming changes from 2056 and earlier:
-    \table
-      Keyword  | Description               | Keyword (old) | Deflt (old)
-      h        | Thickness (shell)         | -   | "h_" + regionName
-      ps       | Pressure (shell)          | -   | "ps_" + regionName
+      f0         | Damping coefficient [1/s]           | scalar | yes | -
+      f1         | Damping coefficient [1/s]           | scalar | yes | -
+      f2         | Damping coefficient [1/s]           | scalar | yes | -
     \endtable
 
     The inherited entries are elaborated in:
@@ -106,12 +90,12 @@ class KirchhoffShell
 
         // Source term fields
 
-        //- Shell thickness [m]
-        areaScalarField h_;
-
         //- External surface source [Pa]
         const areaScalarField ps_;
 
+        //- Thickness [m]
+        areaScalarField h_;
+
         //- Laplace of the displacement
         areaScalarField laplaceW_;
 

src/regionFaModels/liquidFilm/subModels/kinematic/force/contactAngleForces/dynamicContactAngleForce/dynamicContactAngleForce.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2020-2023 OpenCFD Ltd.
+    Copyright (C) 2020-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -26,9 +26,9 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "dynamicContactAngleForce.H"
-#include "addToRunTimeSelectionTable.H"
 #include "Function1.H"
 #include "distributionModel.H"
+#include "addToRunTimeSelectionTable.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -59,6 +59,7 @@ dynamicContactAngleForce::dynamicContactAngleForce
 )
 :
     contactAngleForce(typeName, film, dict),
+    thetaPtr_(nullptr),
     U_vs_thetaPtr_
     (
         Function1<scalar>::NewIfPresent
@@ -80,46 +81,56 @@ dynamicContactAngleForce::dynamicContactAngleForce
         )
     ),
     rndGen_(label(0)),
-    distribution_
-    (
-        distributionModel::New
-        (
-            coeffDict_.subDict("distribution"),
-            rndGen_
-        )
-    )
+    distributionPtr_(nullptr)
 {
     if (U_vs_thetaPtr_ && T_vs_thetaPtr_)
     {
         FatalIOErrorInFunction(dict)
-            << "Entries Utheta and Ttheta could not be used together"
+            << "Only one of Utheta or Ttheta should be provided; "
+            << "both inputs cannot be used together."
             << abort(FatalIOError);
     }
+
+
+    thetaPtr_.emplace
+    (
+        IOobject
+        (
+            IOobject::scopedName(typeName, "theta"),
+            film.regionMesh().time().timeName(),
+            film.regionMesh().thisDb(),
+            IOobject::READ_IF_PRESENT,
+            IOobject::AUTO_WRITE
+        ),
+        film.regionMesh(),
+        dimensionedScalar(dimless, Zero)
+    );
+
+
+    if (coeffDict_.findEntry("distribution"))
+    {
+        distributionPtr_ = distributionModel::New
+        (
+            coeffDict_.subDict("distribution"),
+            rndGen_
+        );
+    }
 }
 
 
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+dynamicContactAngleForce::~dynamicContactAngleForce()
+{}  // distributionModel was forward declared
+
+
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
 tmp<areaScalarField> dynamicContactAngleForce::theta() const
 {
-    auto ttheta = tmp<areaScalarField>::New
-    (
-        IOobject
-        (
-            IOobject::scopedName(typeName, "theta"),
-            film().regionMesh().time().timeName(),
-            film().regionMesh().thisDb(),
-            IOobject::NO_READ,
-            IOobject::NO_WRITE,
-            IOobject::NO_REGISTER
-        ),
-        film().regionMesh(),
-        dimensionedScalar(dimless, Zero)
-    );
-    areaScalarField& theta = ttheta.ref();
+    areaScalarField& theta = thetaPtr_.ref();
     scalarField& thetai = theta.ref();
 
-
     if (U_vs_thetaPtr_)
     {
         // Initialize with the function of film speed
@@ -136,13 +147,16 @@ tmp<areaScalarField> dynamicContactAngleForce::theta() const
         thetai = T_vs_thetaPtr_->value(T());
     }
 
-    // Add the stochastic perturbation
-    forAll(thetai, facei)
+    if (distributionPtr_)
     {
-        thetai[facei] += distribution_->sample();
+        // Add the stochastic perturbation
+        forAll(thetai, facei)
+        {
+            thetai[facei] += distributionPtr_->sample();
+        }
     }
 
-    return ttheta;
+    return thetaPtr_();
 }
 
 

src/regionFaModels/liquidFilm/subModels/kinematic/force/contactAngleForces/dynamicContactAngleForce/dynamicContactAngleForce.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2020-2022 OpenCFD Ltd.
+    Copyright (C) 2020-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -112,6 +112,9 @@ class dynamicContactAngleForce
 {
     // Private Data
 
+        //- Contact-angle field in degrees
+        mutable autoPtr<areaScalarField> thetaPtr_;
+
         //- Contact angle as a function of film speed
         autoPtr<Function1<scalar>> U_vs_thetaPtr_;
 
@@ -121,17 +124,8 @@ class dynamicContactAngleForce
         //- Random number generator
         Random rndGen_;
 
-        //- Parcel size PDF model
-        const autoPtr<distributionModel> distribution_;
-
-
-    // Private Member Functions
-
-        //- No copy construct
-        dynamicContactAngleForce(const dynamicContactAngleForce&) = delete;
-
-        //- No copy assignment
-        void operator=(const dynamicContactAngleForce&) = delete;
+        //- Stochastic perturbation model for contact angle
+        autoPtr<distributionModel> distributionPtr_;
 
 
 protected:
@@ -148,7 +142,7 @@ public:
 
     // Constructors
 
-        //- Construct from surface film model
+        //- Construct from surface film model and dictionary
         dynamicContactAngleForce
         (
             liquidFilmBase& film,
@@ -157,7 +151,7 @@ public:
 
 
     //- Destructor
-    virtual ~dynamicContactAngleForce() = default;
+    virtual ~dynamicContactAngleForce();
 };
 
 

src/regionFaModels/regionFaModel/regionFaModel.C

@@ -27,6 +27,7 @@ License
 
 #include "regionFaModel.H"
 #include "faMesh.H"
+#include "faMeshesRegistry.H"
 #include "Time.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
@@ -73,7 +74,7 @@ Foam::IOobject createModelIOobject
     (
         objName,
         mesh.time().constant(),
-        faMesh::Registry(mesh),
+        faMeshesRegistry::New(mesh).thisDb(),
         IOobjectOption::NO_READ,
         IOobjectOption::NO_WRITE,
         IOobjectOption::REGISTER
@@ -140,71 +141,12 @@ Foam::IOobject createPropertiesIOobject
 
 // * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //
 
-void Foam::regionModels::regionFaModel::constructMeshObjects
-(
-    // Just for error reference
-    const dictionary& dict
-)
+void Foam::regionModels::regionFaModel::constructMeshObjects()
 {
-    regionMeshPtr_.reset(nullptr);
-
-    #if 1
     regionMeshPtr_.reset
     (
         new faMesh(areaName_, primaryMesh_)
     );
-
-    #else
-
-    // With try/catch and error messages
-
-    // DIY
-    // regionMeshPtr_ = faMesh::TryNew(areaName_, primaryMesh_);
-
-    // More heavy handed, but gives a better chance of locating
-    // the source of the error.
-    {
-        const bool oldThrowingError = FatalError.throwing(true);
-        const bool oldThrowingIOerr = FatalIOError.throwing(true);
-
-        try
-        {
-            regionMeshPtr_.reset
-            (
-                new faMesh(areaName_, primaryMesh_)
-            );
-        }
-        catch (const Foam::error& err)
-        {
-            Warning << err << nl << endl;
-
-            // Trickery to get original message
-            err.write(Warning, false);
-        }
-        catch (const Foam::IOerror& err)
-        {
-            Warning << err << nl << endl;
-
-            // Trickery to get original message
-            err.write(Warning, false);
-        }
-
-        FatalError.throwing(oldThrowingError);
-        FatalIOError.throwing(oldThrowingIOerr);
-    }
-
-    if (!regionMeshPtr_)
-    {
-        FatalError
-            << "Failed to create finite-area mesh [" << areaName_
-            << "] for model: "<< modelName_ << nl
-            << "A common cause is an incorrect or"
-               " missing 'area' entry in the setup" << nl
-            << ">>>>" << nl
-            << dict.relativeName() << dict << "<<<<" << endl
-            << exit(FatalError);
-    }
-    #endif
 }
 
 
@@ -292,35 +234,7 @@ Foam::regionModels::regionFaModel::regionFaModel
     regionName_(dict.get<word>("region")),
     coeffs_(dict.subOrEmptyDict(modelName + "Coeffs"))
 {
-    // Suffix hint for variable names
-    if
-    (
-        coeffs_.readIfPresent("suffixing", suffixHint_)
-     || dict.readIfPresent("suffixing", suffixHint_)
-    )
-    {
-        Switch sw = Switch::find(suffixHint_);
-
-        if (sw.good())
-        {
-            if (!sw)  // No suffix
-            {
-                suffixHint_.clear();
-            }
-        }
-        else if (suffixHint_ == "default")
-        {
-            // Use default suffix
-            sw = true;
-        }
-
-        if (sw)  // Default suffix
-        {
-            suffixHint_ = '_' + regionName_;
-        }
-    }
-
-    constructMeshObjects(dict);
+    constructMeshObjects();
     initialise();
 
     if (readFields)
@@ -336,14 +250,9 @@ void Foam::regionModels::regionFaModel::evolve()
 {
     if (active_)
     {
-        Info<< "\nEvolving " << modelName_
-            << " for region " << regionMesh().name();
-
-        if (!polyMesh::regionName(areaName_).empty())
-        {
-            Info<< " [" << areaName_ << "]";
-        }
-        Info<< endl;
+        Info<< "\nEvolving " << modelName_ << " for region "
+            << regionMesh().name() << " : "
+            << polyMesh::regionName(areaName_) << endl;
 
         preEvolveRegion();
 
@@ -356,7 +265,7 @@ void Foam::regionModels::regionFaModel::evolve()
         {
             Info<< incrIndent;
             info();
-            Info<< decrIndent << endl;
+            Info<< endl << decrIndent;
         }
     }
 }

src/regionFaModels/regionFaModel/regionFaModel.H

@@ -57,20 +57,9 @@ Usage
       region     | Name of operand region              | word  | yes  | -
       area       | Name of the finite-area mesh        | word  | no   | region0
       active     | Flag to activate the model          | bool  | yes  | -
-      suffixing  | Suffix hint for model variables     | word  | no   | -
       infoOutput | Flag to activate information output | bool  | no   | false
     \endtable
 
-Note
-    The \c suffixing parameter is a hint that individual models may use
-    when automatically generating variable names internally. For example,
-    a model \em may provide ("T" + suffixing) and ("q" + suffixing)
-    as its default names temperature and flux fields, respectively.
-    If the user specifies \c suffixing = "_foo", those \em default names
-    would then become "T_foo" and "q_foo", respectively.
-    Suffixing (true|false|none|default|...) currently selects between
-    no suffix and ('_'+region).
-
 SourceFiles
     regionFaModelI.H
     regionFaModel.C
@@ -101,7 +90,7 @@ class regionFaModel
     // Private Member Functions
 
         //- Construct region mesh and fields
-        void constructMeshObjects(const dictionary&);
+        void constructMeshObjects();
 
         //- Initialise the region
         void initialise();
@@ -129,21 +118,18 @@ protected:
         //- Model name
         const word modelName_;
 
-        //- Suffix hint for automatic model variable names (default: "")
-        word suffixHint_;
-
-        //- The finite-area mesh name (default: region0)
+        //- The finite-area mesh name
         word areaName_;
 
         //- Region name
         word regionName_;
 
-        //- Model coefficients dictionary
-        dictionary coeffs_;
-
         //- Pointer to the region mesh database
         autoPtr<faMesh> regionMeshPtr_;
 
+        //- Model coefficients dictionary
+        dictionary coeffs_;
+
         //- Dictionary of output properties
         autoPtr<IOdictionary> outputPropertiesPtr_;
 
@@ -238,15 +224,6 @@ public:
         //- Return mapping between surface and volume fields
         const volSurfaceMapping& vsm() const;
 
-        //- The suffix hint for automatic model variable names
-        const word& suffixHint() const noexcept { return suffixHint_; }
-
-        //- Return the concatenation of \p base and the suffix hint
-        inline word suffixed(const char* base) const;
-
-        //- Return the concatenation of \p base and the suffix hint
-        inline word suffixed(const std::string& base) const;
-
 
     // Evolution
 

src/regionFaModels/regionFaModel/regionFaModelI.H

@@ -27,7 +27,7 @@ License
 
 #include "regionFaModel.H"
 
-// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 inline const Foam::faMesh& Foam::regionModels::regionFaModel::regionMesh() const
 {
@@ -106,18 +106,4 @@ inline bool Foam::regionModels::regionFaModel::isRegionPatch
 }
 
 
-inline Foam::word
-Foam::regionModels::regionFaModel::suffixed(const char* base) const
-{
-    return word(base + suffixHint_);
-}
-
-
-inline Foam::word
-Foam::regionModels::regionFaModel::suffixed(const std::string& base) const
-{
-    return word(base + suffixHint_);
-}
-
-
 // ************************************************************************* //

src/regionFaModels/thermalShell/thermalShell.C

@@ -123,29 +123,14 @@ thermalShell::thermalShell
 )
 :
     thermalShellModel(modelType, mesh, dict),
-    hName_(dict.getOrDefault<word>("h", suffixed("hs"))),
-    qsName_(dict.getOrDefault<word>("qs", suffixed("qs"))),
-    qrName_(dict.getOrDefault<word>("qr", "none")),
     nNonOrthCorr_(1),
     // Only need/want thermal solid properties
     thermo_(dict.subDict("thermo"), solidProperties::THERMAL),
-    h_
-    (
-        IOobject
-        (
-            hName_,
-            regionMesh().time().timeName(),
-            regionMesh().thisDb(),
-            IOobject::MUST_READ,
-            IOobject::AUTO_WRITE
-        ),
-        regionMesh()
-    ),
     qs_
     (
         IOobject
         (
-            qsName_,
+            "qs_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::READ_IF_PRESENT,
@@ -154,6 +139,19 @@ thermalShell::thermalShell
         regionMesh(),
         dimensionedScalar(dimPower/dimArea, Zero)
     ),
+    h_
+    (
+        IOobject
+        (
+            "h_" + regionName_,
+            regionMesh().time().timeName(),
+            regionMesh().thisDb(),
+            IOobject::MUST_READ,
+            IOobject::AUTO_WRITE
+        ),
+        regionMesh()
+    ),
+    qrName_(dict.getOrDefault<word>("qr", "none")),
     thickness_(dict.getOrDefault<scalar>("thickness", 0))
 {
     init(dict);

src/regionFaModels/thermalShell/thermalShell.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2019-2025 OpenCFD Ltd.
+    Copyright (C) 2019-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -56,28 +56,11 @@ Usage
 
     where the entries mean:
     \table
-      Property   | Description                    | Type  | Reqd   | Deflt
-      thermalShellModel | Type name: thermalShell | word  | yes    | -
-      h          | Name of thickness field        | word  | no     | hs (suffix)
-      qs         | Name of source field           | word  | no     | qs (suffix)
-      qr         | Name of radiative heat flux field | word | no   | none
-      thermo     | Solid thermal properties       | dict | yes | -
-      thickness  | Uniform shell thickness [m]    | scalar | choice | -
-    \endtable
-
-    Fields/variables used:
-    \table
-      Property  | Description               | Type  | Deflt
-      h         | Thickness                 | shell | hs (suffix)
-      qs        | Source field              | shell | qs (suffix)
-      qr        | Radiative heat flux field | volume | none
-    \endtable
-
-    Note the following naming changes from 2056 and earlier:
-    \table
-      Keyword  | Description               | Keyword (old) | Deflt (old)
-      h        | Temperature (volume)      | h    | "h_" + regionName
-      qs       | Temperature (shell)       | qs   | "qs_" + regionName
+      Property   | Description                      | Type  | Reqd   | Deflt
+      thermalShellModel | Type name: thermalShell   | word  | yes    | -
+      thermo     | Solid thermal properties         | dictionary | yes | -
+      qr         | Name of radiative heat flux field | word | no     | none
+      thickness  | Uniform film thickness [m]       | scalar | choice | -
     \endtable
 
     The inherited entries are elaborated in:
@@ -85,6 +68,7 @@ Usage
 
 SourceFiles
     thermalShell.C
+    thermalShellI.H
 
 \*---------------------------------------------------------------------------*/
 
@@ -124,38 +108,31 @@ protected:
 
     // Protected Data
 
-        //- Name of shell thickness [height] field (default: "hs" + suffix)
-        const word hName_;
+        // Solution parameters
 
-        //- Name of surface energy source (default: "qs" + suffix)
-        const word qsName_;
-
-        //- Name of (volume) radiative flux field (default: none)
-        const word qrName_;
+            //- Number of non orthogonal correctors
+            label nNonOrthCorr_;
 
 
-    // Solution Parameters
+        // Thermo properties
 
-        //- Number of non orthogonal correctors
-        label nNonOrthCorr_;
+            //- Solid properties
+            solidProperties thermo_;
 
 
-    // Thermo properties
+        // Source term fields
 
-        //- Solid properties
-        solidProperties thermo_;
+            //- External surface energy source [J/m2/s]
+            areaScalarField qs_;
 
+            //- Film thickness [m]
+            areaScalarField h_;
 
-    // Source term fields
+            //- Name of the primary region radiative flux
+            const word qrName_;
 
-        //- Shell thickness field [m]
-        areaScalarField h_;
-
-        //- External surface energy source [J/m2/s]
-        areaScalarField qs_;
-
-        //- Uniform shell thickness [m]
-        scalar thickness_;
+            //- Uniform film thickness [m]
+            scalar thickness_;
 
 
     // Protected Member Functions
@@ -197,7 +174,7 @@ public:
 
         // Fields
 
-            //- Return the shell specific heat capacity [J/kg/K]
+            //- Return the film specific heat capacity [J/kg/K]
             const tmp<areaScalarField> Cp() const;
 
             //- Return density [kg/m3]

src/regionFaModels/thermalShellModel/thermalShellModel.C

@@ -50,14 +50,13 @@ thermalShellModel::thermalShellModel
 )
 :
     regionFaModel(mesh, "thermalShell", modelType, dict, true),
-    TName_(dict.getOrDefault<word>("T", suffixed("Ts"))),
-    TprimaryName_(dict.getOrDefault<word>("Tprimary", "T")),
-    Tp_(mesh.lookupObject<volScalarField>(TprimaryName_)),
+    TName_(dict.get<word>("T")),
+    Tp_(mesh.lookupObject<volScalarField>(TName_)),
     T_
     (
         IOobject
         (
-            TName_,
+            "Ts_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::MUST_READ,
@@ -72,8 +71,8 @@ thermalShellModel::thermalShellModel
 {
     if (faOptions_.optionList::empty())
     {
-        Info<< "No finite-area options present for area:"
-            << regionFaModel::areaName() << endl;
+        Info<< "No finite area options present for area : "
+            << polyMesh::regionName(regionFaModel::areaName()) << endl;
     }
 }
 

src/regionFaModels/thermalShellModel/thermalShellModel.H

@@ -24,7 +24,7 @@ License
     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
 Class
-    Foam::regionModels::thermalShellModel
+    Foam::regionModels::thermalShellModels::thermalShellModel
 
 Description
     Intermediate class for thermal-shell finite-area models.
@@ -34,12 +34,12 @@ Usage
     \verbatim
     <patchName>
     {
+        // Mandatory entries
+        T                     <word>;
+
         // Optional entries
         thermalShellModel     <word>;
 
-        T                     <word>;
-        Tprimary              <word>;
-
         // Inherited entries
         ...
     }
@@ -47,27 +47,12 @@ Usage
 
     where the entries mean:
     \table
-      Property  | Description                       | Type  | Reqd | Deflt
-      T         | Name of operand temperature field | word  | no   | Ts (suffix)
-      Tprimary  | Name of primary temperature field | word  | no   | T
-      thermalShellModel | Name of thermalShellModel thermal-shell model <!--
+      Property   | Description                       | Type  | Reqd | Deflt
+      T          | Name of operand temperature field | word  | yes  | -
+      thermalShellModel | Name of thermal-shell model <!--
                         -->                      | word | choice | -
     \endtable
 
-    Fields/variables used:
-    \table
-      Property  | Description               | Type   | Deflt
-      T         | Temperature               | shell  | Ts (suffix)
-      Tprimary  | Temperature               | volume | T
-    \endtable
-
-    \b BREAKING Naming changes from 2056 and earlier:
-    \table
-      Keyword  | Description               | Keyword (old) | Deflt (old)
-      T        | Temperature (shell)       | -   | "Ts_" + regionName
-      Tprimary | Temperature (volume)      | T   | -
-    \endtable
-
     The inherited entries are elaborated in:
       - \link regionFaModel.H \endlink
 
@@ -104,11 +89,8 @@ protected:
 
     // Protected Data
 
-        //- Name of shell temperature field (default: "Ts" + suffix)
-        const word TName_;
-
-        //- Name of volume temperature field (default: "T")
-        const word TprimaryName_;
+        //- Name of the temperature field
+        word TName_;
 
         //- Primary (volume) region temperature
         const volScalarField& Tp_;

src/regionFaModels/vibrationShellModel/vibrationShellModel.C

@@ -53,7 +53,7 @@ vibrationShellModel::vibrationShellModel
     (
         IOobject
         (
-            dict.getOrDefault<word>("ws", suffixed("ws")),
+            "ws_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::MUST_READ,
@@ -65,7 +65,7 @@ vibrationShellModel::vibrationShellModel
     (
         IOobject
         (
-            dict.getOrDefault<word>("as", suffixed("as")),
+            "as_" + regionName_,
             regionMesh().time().timeName(),
             regionMesh().thisDb(),
             IOobject::NO_READ,

src/regionFaModels/vibrationShellModel/vibrationShellModel.H

@@ -24,7 +24,7 @@ License
     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
 Class
-    Foam::regionModels::vibrationShellModel
+    Foam::regionModels::thermalShellModels::vibrationShellModel
 
 Description
     Intermediate class for vibration-shell finite-area models.
@@ -52,19 +52,9 @@ Usage
     \table
       Property   | Description                            | Type  | Reqd | Deflt
       vibrationShellModel | Name of vibration-shell model | word | yes | -
-      p          | Name of primary pressure field         | word | yes | -
-      solid      | Solid properties                       | dict | yes | -
-      as         | Name of shell acceleration field    | word | no | as (suffix)
-      ps         | Name of pressure (source) on shell  | word | no | ps (suffix)
-      ws         | Name of shell displacement field    | word | no | ws (suffix)
-    \endtable
-
-    Naming changes from 2056 and earlier:
-    \table
-      Keyword  | Description               | Keyword (old) | Deflt (old)
-      as       | Acceleration (shell)      | - | "as_" + regionName
-      ps       | Pressure on shell         | - | "ps_" + regionName
-      ws       | Displacement (shell)      | - | "ws_" + regionName
+      p          | Name of the coupled field in the primary <!--
+                 --> region                               | word | yes | -
+      solid      | Solid properties                 | dictionary | yes | -
     \endtable
 
     The inherited entries are elaborated in:
@@ -103,19 +93,19 @@ protected:
 
     // Protected Data
 
-        //- Shell displacement [m]
+        //- Shell displacement
         areaScalarField w_;
 
-        //- Shell acceleration [m/s2]
+        //- Shell acceleration
         areaScalarField a_;
 
         //- Solid properties
         solidProperties solid_;
 
-        //- Name of primary region acoustic pressure field
+        //- Name of the coupled field in the primary region
         word pName_;
 
-        //- Primary region acoustic pressure [Pa]
+        //- Primary region acoustic pressure
         const volScalarField& pa_;
 
         //- Reference to faOptions
@@ -177,26 +167,26 @@ public:
 
     // Member Functions
 
-        //- Return the primary region presssure
-        const volScalarField& pa() const noexcept { return pa_; }
+       //- Return primary region pa
+       const volScalarField& pa() const noexcept { return pa_; }
 
-        //- Return the shell displacement
-        const areaScalarField& w() const noexcept { return w_; }
+       //- Return shell displacement
+       const areaScalarField& w() const noexcept { return w_; }
 
-        //- Return the shell acceleration
-        const areaScalarField& a() const noexcept { return a_; }
+       //- Return shell acceleration
+       const areaScalarField& a() const noexcept { return a_; }
 
-        //- Return faOptions
-        Foam::fa::options& faOptions() noexcept { return faOptions_; }
+       //- Return faOptions
+       Foam::fa::options& faOptions() noexcept { return faOptions_; }
 
-        //- Return solid properties
-        const solidProperties& solid() const noexcept { return solid_; }
+       //- Return solid properties
+       const solidProperties& solid() const noexcept { return solid_; }
 
 
    // Evolution
 
-        //- Pre-evolve region
-        virtual void preEvolveRegion();
+       //- Pre-evolve region
+       virtual void preEvolveRegion();
 };
 
 

tutorials/compressible/acousticFoam/obliqueAirJet/main/0.orig/finite-area/h_vibrationShell

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       areaScalarField;
-    object      hs;
+    object      h_ceilingShell;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

tutorials/compressible/acousticFoam/obliqueAirJet/main/0.orig/finite-area/ws_vibrationShell

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       areaScalarField;
-    object      ws;
+    object      wS;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

tutorials/compressible/acousticFoam/obliqueAirJet/main/0.orig/pa

@@ -41,7 +41,7 @@ boundaryField
             nu      0.22;
         }
 
-        region                vibration;
+        region                vibrationShell;
         vibrationShellModel   KirchhoffShell;
 
         f0             0.04;

tutorials/compressible/acousticFoam/obliqueAirJet/main/system/finite-area/faOptions

@@ -17,13 +17,12 @@ FoamFile
 pressure
 {
     type            externalFileSource;
-    //fieldName       ws_shell;
-    fieldName       ws;
+    fieldName       ws_vibrationShell;
     tableName       p;
     active          true;
     timeStart       0.001;
     duration        0.03;
-    region          vibration;
+    region          vibrationShell;
     selectionMode   all;
 
     sampleFormat    ensight;