ENH: finiteArea: enable cache-gradient mechanism

src/finiteArea/finiteArea/fac/facGrad.C

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -31,6 +32,7 @@ License
 #include "facEdgeIntegrate.H"
 #include "faMesh.H"
 #include "faGradScheme.H"
+#include "gaussFaGrad.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -57,20 +59,10 @@ grad
     const GeometricField<Type, faePatchField, edgeMesh>& ssf
 )
 {
-    const areaVectorField &n = ssf.mesh().faceAreaNormals();
+    return fa::gaussGrad<Type>::gradf(ssf, "grad(" + ssf.name() + ')');
-    typedef typename outerProduct<vector,Type>::type GradType;
-
-    tmp<GeometricField<GradType, faPatchField, areaMesh>> tgGrad =
-        fac::edgeIntegrate(ssf.mesh().Sf()*ssf);
-
-    GeometricField<GradType, faPatchField, areaMesh>& gGrad = tgGrad.ref();
-
-    gGrad -= n*(n & gGrad);
-    gGrad.correctBoundaryConditions();
-
-    return tgGrad;
 }
 
+
 template<class Type>
 tmp
 <
@@ -108,22 +100,11 @@ grad
     const word& name
 )
 {
-    const areaVectorField &n = vf.mesh().faceAreaNormals();
+    return fa::gradScheme<Type>::New
-    typedef typename outerProduct<vector,Type>::type GradType;
+    (
-
+        vf.mesh(),
-    tmp<GeometricField<GradType, faPatchField, areaMesh>> tgGrad =
+        vf.mesh().gradScheme(name)
-        fa::gradScheme<Type>::New
+    )().grad(vf, name);
-        (
-            vf.mesh(),
-            vf.mesh().gradScheme(name)
-        ).ref().grad(vf);
-
-    GeometricField<GradType, faPatchField, areaMesh>& gGrad = tgGrad.ref();
-
-    gGrad -= n*(n & gGrad);
-    gGrad.correctBoundaryConditions();
-
-    return tgGrad;
 }
 
 

src/finiteArea/finiteArea/gradSchemes/faGradScheme/faGradScheme.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
-    Copyright (C) 2019-2021 OpenCFD Ltd.
+    Copyright (C) 2019-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -28,6 +28,8 @@ License
 
 #include "fa.H"
 #include "HashTable.H"
+#include "objectRegistry.H"
+#include "solution.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -83,11 +85,112 @@ tmp<gradScheme<Type>> gradScheme<Type>::New
 }
 
 
-// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 template<class Type>
-gradScheme<Type>::~gradScheme()
+tmp
-{}
+<
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        faPatchField,
+        areaMesh
+    >
+>
+gradScheme<Type>::grad
+(
+    const GeometricField<Type, faPatchField, areaMesh>& vsf,
+    const word& name
+) const
+{
+    typedef typename outerProduct<vector, Type>::type GradType;
+    typedef GeometricField<GradType, faPatchField, areaMesh> GradFieldType;
+
+    GradFieldType* pgGrad =
+        mesh().thisDb().template getObjectPtr<GradFieldType>(name);
+
+    if (!this->mesh().cache(name)) // || this->mesh().changing()
+    {
+        // Delete any old occurrences to avoid double registration
+        if (pgGrad && pgGrad->ownedByRegistry())
+        {
+            solution::cachePrintMessage("Deleting", name, vsf);
+            delete pgGrad;
+        }
+
+        solution::cachePrintMessage("Calculating", name, vsf);
+        return calcGrad(vsf, name);
+    }
+
+
+    if (!pgGrad)
+    {
+        solution::cachePrintMessage("Calculating and caching", name, vsf);
+
+        pgGrad = calcGrad(vsf, name).ptr();
+        regIOobject::store(pgGrad);
+    }
+    else
+    {
+        if (pgGrad->upToDate(vsf))
+        {
+            solution::cachePrintMessage("Reusing", name, vsf);
+        }
+        else
+        {
+            solution::cachePrintMessage("Updating", name, vsf);
+            delete pgGrad;
+
+            pgGrad = calcGrad(vsf, name).ptr();
+            regIOobject::store(pgGrad);
+        }
+    }
+
+    return *pgGrad;
+}
+
+
+template<class Type>
+tmp
+<
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        faPatchField,
+        areaMesh
+    >
+>
+gradScheme<Type>::grad
+(
+    const GeometricField<Type, faPatchField, areaMesh>& vsf
+) const
+{
+    return grad(vsf, "grad(" + vsf.name() + ')');
+}
+
+
+template<class Type>
+tmp
+<
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        faPatchField,
+        areaMesh
+    >
+>
+gradScheme<Type>::grad
+(
+    const tmp<GeometricField<Type, faPatchField, areaMesh>>& tvsf
+) const
+{
+    typedef typename outerProduct<vector, Type>::type GradType;
+    typedef GeometricField<GradType, faPatchField, areaMesh> GradFieldType;
+
+    tmp<GradFieldType> tgrad = grad(tvsf());
+    tvsf.clear();
+    return tgrad;
+}
 
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

src/finiteArea/finiteArea/gradSchemes/faGradScheme/faGradScheme.H

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -113,26 +114,62 @@ public:
 
 
     //- Destructor
-    virtual ~gradScheme();
+    virtual ~gradScheme() = default;
 
 
     // Member Functions
 
         //- Return mesh reference
-        const faMesh& mesh() const
+        const faMesh& mesh() const { return mesh_; }
-        {
+
-            return mesh_;
+        //- Calculate and return the grad of the given field.
-        }
+        //  Used by grad either to recalculate the cached gradient when it is
+        //  out of date with respect to the field or when it is not cached.
+        virtual tmp
+        <
+            GeometricField
+            <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
+        > calcGrad
+        (
+            const GeometricField<Type, faPatchField, areaMesh>&,
+            const word& name
+        ) const = 0;
 
         //- Calculate and return the grad of the given field
-        virtual tmp
+        //- which may have been cached
+        tmp
+        <
+            GeometricField
+            <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
+        > grad
+        (
+            const GeometricField<Type, faPatchField, areaMesh>&,
+            const word& name
+        ) const;
+
+        //- Calculate and return the grad of the given field
+        //- with the default name
+        //- which may have been cached
+        tmp
         <
             GeometricField
             <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
         > grad
         (
             const GeometricField<Type, faPatchField, areaMesh>&
-        ) const = 0;
+        ) const;
+
+        //- Calculate and return the grad of the given field
+        //- with the default name
+        //- which may have been cached
+        tmp
+        <
+            GeometricField
+            <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
+        > grad
+        (
+            const tmp<GeometricField<Type, faPatchField, areaMesh>>&
+        ) const;
 };
 
 

src/finiteArea/finiteArea/gradSchemes/gaussFaGrad/gaussFaGrad.C

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -47,17 +48,52 @@ tmp
 <
     GeometricField
     <
-        typename outerProduct<vector, Type>::type, faPatchField, areaMesh
+        typename outerProduct<vector, Type>::type,
+        faPatchField,
+        areaMesh
     >
 >
-gaussGrad<Type>::grad
+gaussGrad<Type>::gradf
 (
-    const GeometricField<Type, faPatchField, areaMesh>& vsf
+    const GeometricField<Type, faePatchField, edgeMesh>& ssf,
+    const word& name
+)
+{
+    const areaVectorField &n = ssf.mesh().faceAreaNormals();
+    typedef typename outerProduct<vector,Type>::type GradType;
+
+    tmp<GeometricField<GradType, faPatchField, areaMesh>> tgGrad =
+        fac::edgeIntegrate(ssf.mesh().Sf()*ssf);
+
+    GeometricField<GradType, faPatchField, areaMesh>& gGrad = tgGrad.ref();
+
+    gGrad -= n*(n & gGrad);
+    gGrad.correctBoundaryConditions();
+
+    return tgGrad;
+}
+
+
+template<class Type>
+tmp
+<
+    GeometricField
+    <
+        typename outerProduct<vector, Type>::type,
+        faPatchField,
+        areaMesh
+    >
+>
+gaussGrad<Type>::calcGrad
+(
+    const GeometricField<Type, faPatchField, areaMesh>& vsf,
+    const word& name
 ) const
 {
     typedef typename outerProduct<vector, Type>::type GradType;
+    typedef GeometricField<GradType, faPatchField, areaMesh> GradFieldType;
 
-    tmp<GeometricField<GradType, faPatchField, areaMesh>> tgGrad
+    tmp<GradFieldType> tgGrad
     (
         fac::edgeIntegrate
         (
@@ -65,12 +101,11 @@ gaussGrad<Type>::grad
            *tinterpScheme_().interpolate(vsf)
         )
     );
-
+    GradFieldType& gGrad = tgGrad.ref();
-    GeometricField<GradType, faPatchField, areaMesh>& gGrad = tgGrad.ref();
 
     gGrad.correctBoundaryConditions();
+    gGrad.rename(name);
 
-    gGrad.rename("grad(" + vsf.name() + ')');
     correctBoundaryConditions(vsf, gGrad);
 
     return tgGrad;

src/finiteArea/finiteArea/gradSchemes/gaussFaGrad/gaussFaGrad.H

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -62,8 +63,9 @@ class gaussGrad
 :
     public fa::gradScheme<Type>
 {
-    // Private data
+    // Private Data
 
+        //- Interpolation scheme
         tmp<edgeInterpolationScheme<Type>> tinterpScheme_;
 
 
@@ -118,17 +120,32 @@ public:
 
     // Member Functions
 
-        //- Return the gradient of the given field calculated
+        //- Return the gradient of the given field
-        //  using Gauss' theorem on the interpolated field
+        //- calculated using Gauss' theorem on the given surface field
+        static
         tmp
         <
             GeometricField
             <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
-        > grad
+        > gradf
         (
-            const GeometricField<Type, faPatchField, areaMesh>&
+            const GeometricField<Type, faePatchField, edgeMesh>&,
+            const word& name
+        );
+
+        //- Return the gradient of the given field to the
+        //- gradScheme::grad for optional caching
+        virtual tmp
+        <
+            GeometricField
+            <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
+        > calcGrad
+        (
+            const GeometricField<Type, faPatchField, areaMesh>& vsf,
+            const word& name
         ) const;
 
+
         //- Correct the boundary values of the gradient using the patchField
         // snGrad functions
         static void correctBoundaryConditions

src/finiteArea/finiteArea/gradSchemes/leastSquaresFaGrad/leastSquaresFaGrad.C

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -45,18 +46,20 @@ namespace fa
 {
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
 template<class Type>
 tmp
 <
     GeometricField
     <
-        typename outerProduct<vector, Type>::type, faPatchField, areaMesh
+        typename outerProduct<vector, Type>::type,
+        faPatchField,
+        areaMesh
     >
 >
-leastSquaresFaGrad<Type>::grad
+leastSquaresFaGrad<Type>::calcGrad
 (
-    const GeometricField<Type, faPatchField, areaMesh>& vsf
+    const GeometricField<Type, faPatchField, areaMesh>& vsf,
+    const word& name
 ) const
 {
     typedef typename outerProduct<vector, Type>::type GradType;
@@ -69,7 +72,7 @@ leastSquaresFaGrad<Type>::grad
         (
             IOobject
             (
-                "grad(" + vsf.name() + ')',
+                name,
                 vsf.instance(),
                 vsf.db(),
                 IOobject::NO_READ,

src/finiteArea/finiteArea/gradSchemes/leastSquaresFaGrad/leastSquaresFaGrad.H

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -93,13 +94,16 @@ public:
 
     // Member Functions
 
+        //- Return the gradient of the given field to the
+        //- gradScheme::grad for optional caching
         virtual tmp
         <
             GeometricField
             <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
-        > grad
+        > calcGrad
         (
-            const GeometricField<Type, faPatchField, areaMesh>&
+            const GeometricField<Type, faPatchField, areaMesh>& vsf,
+            const word& name
         ) const;
 };
 

src/finiteArea/finiteArea/gradSchemes/limitedGradSchemes/edgeLimitedFaGrad/edgeLimitedFaGrad.H

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -116,13 +117,16 @@ public:
 
     // Member Functions
 
-        tmp
+        //- Return the gradient of the given field to the
+        //- gradScheme::grad for optional caching
+        virtual tmp
         <
             GeometricField
             <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
-        > grad
+        > calcGrad
         (
-            const GeometricField<Type, faPatchField, areaMesh>&
+            const GeometricField<Type, faPatchField, areaMesh>& vsf,
+            const word& name
         ) const;
 };
 

src/finiteArea/finiteArea/gradSchemes/limitedGradSchemes/edgeLimitedFaGrad/edgeLimitedFaGrads.C

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -72,14 +73,15 @@ inline void edgeLimitedGrad<Type>::limitEdge
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 template<>
-tmp<areaVectorField> edgeLimitedGrad<scalar>::grad
+tmp<areaVectorField> edgeLimitedGrad<scalar>::calcGrad
 (
-    const areaScalarField& vsf
+    const areaScalarField& vsf,
+    const word& name
 ) const
 {
     const faMesh& mesh = vsf.mesh();
 
-    tmp<areaVectorField> tGrad = basicGradScheme_().grad(vsf);
+    tmp<areaVectorField> tGrad = basicGradScheme_().calcGrad(vsf, name);
 
     if (k_ < SMALL)
     {
@@ -206,14 +208,15 @@ tmp<areaVectorField> edgeLimitedGrad<scalar>::grad
 
 
 template<>
-tmp<areaTensorField> edgeLimitedGrad<vector>::grad
+tmp<areaTensorField> edgeLimitedGrad<vector>::calcGrad
 (
-    const areaVectorField& vvf
+    const areaVectorField& vvf,
+    const word& name
 ) const
 {
     const faMesh& mesh = vvf.mesh();
 
-    tmp<areaTensorField> tGrad = basicGradScheme_().grad(vvf);
+    tmp<areaTensorField> tGrad = basicGradScheme_().grad(vvf, name);
 
     if (k_ < SMALL)
     {

src/finiteArea/finiteArea/gradSchemes/limitedGradSchemes/faceLimitedFaGrad/faceLimitedFaGrad.H

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -118,14 +119,16 @@ public:
             const Type& extrapolate
         );
 
-
+        //- Return the gradient of the given field to the
-        tmp
+        //- gradScheme::grad for optional caching
+        virtual tmp
         <
             GeometricField
             <typename outerProduct<vector, Type>::type, faPatchField, areaMesh>
-        > grad
+        > calcGrad
         (
-            const GeometricField<Type, faPatchField, areaMesh>&
+            const GeometricField<Type, faPatchField, areaMesh>& vsf,
+            const word& name
         ) const;
 };
 

src/finiteArea/finiteArea/gradSchemes/limitedGradSchemes/faceLimitedFaGrad/faceLimitedFaGrads.C

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
+    Copyright (C) 2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -94,14 +95,15 @@ inline void faceLimitedGrad<Type>::limitEdge
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 template<>
-tmp<areaVectorField> faceLimitedGrad<scalar>::grad
+tmp<areaVectorField> faceLimitedGrad<scalar>::calcGrad
 (
-    const areaScalarField& vsf
+    const areaScalarField& vsf,
+    const word& name
 ) const
 {
     const faMesh& mesh = vsf.mesh();
 
-    tmp<areaVectorField> tGrad = basicGradScheme_().grad(vsf);
+    tmp<areaVectorField> tGrad = basicGradScheme_().calcGrad(vsf, name);
 
     if (k_ < SMALL)
     {
@@ -243,14 +245,15 @@ tmp<areaVectorField> faceLimitedGrad<scalar>::grad
 
 
 template<>
-tmp<areaTensorField> faceLimitedGrad<vector>::grad
+tmp<areaTensorField> faceLimitedGrad<vector>::calcGrad
 (
-    const areaVectorField& vsf
+    const areaVectorField& vsf,
+    const word& name
 ) const
 {
     const faMesh& mesh = vsf.mesh();
 
-    tmp<areaTensorField> tGrad = basicGradScheme_().grad(vsf);
+    tmp<areaTensorField> tGrad = basicGradScheme_().grad(vsf, name);
 
     if (k_ < SMALL)
     {

tutorials/finiteArea/liquidFilmFoam/cylinder/system/faSolution

@@ -44,5 +44,11 @@ relaxationFactors
     Us  0.5;
 }
 
+cache
+{
+    grad(h);
+    grad(Us);
+}
+
 
 // ************************************************************************* //