From 6a8ddbb296f5680c39b9630cad379149b1639e3c Mon Sep 17 00:00:00 2001
From: Andrew Heather <>
Date: Wed, 16 Mar 2022 19:32:44 +0000
Subject: [PATCH] ENH: Added new solidBodyFvGeometryScheme

Geometry calculation scheme that performs geometry updates only in regions
where the mesh has changed, identified by comparing current and old points.

Example usage in fvSchemes:

    geometry
    {
        type            solidBody;

        // Optional entries

        // If set to false, update the entire mesh
        partialUpdate   yes;

        // Cache the motion addressing (changed points, faces, cells etc)
        cacheMotion     yes;
    }
---
 src/finiteVolume/Make/files                   |   1 +
 .../solidBody/solidBodyFvGeometryScheme.C     | 341 ++++++++++++++++++
 .../solidBody/solidBodyFvGeometryScheme.H     | 141 ++++++++
 3 files changed, 483 insertions(+)
 create mode 100644 src/finiteVolume/fvMesh/fvGeometryScheme/solidBody/solidBodyFvGeometryScheme.C
 create mode 100644 src/finiteVolume/fvMesh/fvGeometryScheme/solidBody/solidBodyFvGeometryScheme.H

diff --git a/src/finiteVolume/Make/files b/src/finiteVolume/Make/files
index 44c72d11ae..00124f2636 100644
--- a/src/finiteVolume/Make/files
+++ b/src/finiteVolume/Make/files
@@ -8,6 +8,7 @@ $(fvGeometryScheme)/highAspectRatio/highAspectRatioFvGeometryScheme.C
 $(fvGeometryScheme)/highAspectRatio/cellAspectRatio.C
 $(fvGeometryScheme)/averageNeighbour/averageNeighbourFvGeometryScheme.C
 $(fvGeometryScheme)/stabilised/stabilisedFvGeometryScheme.C
+$(fvGeometryScheme)/solidBody/solidBodyFvGeometryScheme.C
 
 surfaceInterpolation = interpolation/surfaceInterpolation
 $(surfaceInterpolation)/surfaceInterpolation/surfaceInterpolation.C
diff --git a/src/finiteVolume/fvMesh/fvGeometryScheme/solidBody/solidBodyFvGeometryScheme.C b/src/finiteVolume/fvMesh/fvGeometryScheme/solidBody/solidBodyFvGeometryScheme.C
new file mode 100644
index 0000000000..7c48fb9fb6
--- /dev/null
+++ b/src/finiteVolume/fvMesh/fvGeometryScheme/solidBody/solidBodyFvGeometryScheme.C
@@ -0,0 +1,341 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2021-2022 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "solidBodyFvGeometryScheme.H"
+#include "addToRunTimeSelectionTable.H"
+#include "surfaceFields.H"
+#include "primitiveMeshTools.H"
+#include "emptyPolyPatch.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(solidBodyFvGeometryScheme, 0);
+    addToRunTimeSelectionTable
+    (
+        fvGeometryScheme,
+        solidBodyFvGeometryScheme,
+        dict
+    );
+}
+
+
+void Foam::solidBodyFvGeometryScheme::setMeshMotionData()
+{
+    if (!cacheInitialised_ || !cacheMotion_)
+    {
+        DebugInFunction << "Creating cache" << endl;
+
+        changedFaceIDs_.clear();    // used for face areas, meshPhi
+        changedPatchIDs_.clear();   // used for meshPhi
+        changedCellIDs_.clear();    // used for cell volumes
+
+        const pointField& oldPoints = mesh_.oldPoints();
+        const pointField& currPoints = mesh_.points();
+
+        if (oldPoints.size() != currPoints.size())
+        {
+            FatalErrorInFunction
+                << "Old and current points sizes must be the same. "
+                << "Old points:" << oldPoints.size()
+                << " Current points:" << currPoints.size()
+                << abort(FatalError);
+        }
+
+        bitSet changedPoints(oldPoints.size());
+
+        // Check for non-identical points
+        forAll(changedPoints, pointi)
+        {
+            changedPoints.set(pointi, oldPoints[pointi] != currPoints[pointi]);
+        }
+
+        DebugInfo
+            << "SBM --- Changed points:"
+            << returnReduce(changedPoints.count(), sumOp<label>())
+            << endl;
+
+        // Quick return if no points have moved
+        if (returnReduce(changedPoints.none(), andOp<label>()))
+        {
+            return;
+        }
+
+        bitSet cellIDs(mesh_.nCells());
+        bitSet faceIDs(mesh_.nFaces());
+
+        const auto& pointFaces = mesh_.pointFaces();
+        const auto& own = mesh_.faceOwner();
+        const auto& nbr = mesh_.faceNeighbour();
+
+        // Identify faces and cells attached to moving points
+        for (const label pointi : changedPoints)
+        {
+            for (const auto facei : pointFaces[pointi])
+            {
+                faceIDs.set(facei);
+
+                cellIDs.set(own[facei]);
+                if (facei < mesh_.nInternalFaces())
+                {
+                    cellIDs.set(nbr[facei]);
+                }
+            }
+        }
+
+        changedCellIDs_ = cellIDs.toc();
+
+        DebugInfo
+            << "SBM --- Changed cells:"
+            << returnReduce(changedCellIDs_.size(), sumOp<label>())
+            << endl;
+
+
+        // Construct face and patch ID info
+
+        const auto changedFaceFlag = faceIDs.values();
+
+        DynamicList<label> changedFaceIDs(faceIDs.count());
+        DynamicList<label> changedPatchIDs(faceIDs.count());
+        for (label facei = 0; facei < mesh_.nInternalFaces(); ++facei)
+        {
+            if (changedFaceFlag[facei])
+            {
+                changedFaceIDs.append(facei);
+                changedPatchIDs.append(-1);
+            }
+        }
+
+        const auto& pbm = mesh_.boundaryMesh();
+        for (label patchi = 0; patchi < pbm.size(); ++patchi)
+        {
+            const polyPatch& pp = pbm[patchi];
+
+            for (const label meshFacei : pp.range())
+            {
+                if (changedFaceFlag[meshFacei])
+                {
+                    changedFaceIDs.append(meshFacei);
+                    changedPatchIDs.append(patchi);
+                }
+            }
+        }
+
+        changedFaceIDs_.transfer(changedFaceIDs);
+        changedPatchIDs_.transfer(changedPatchIDs);
+    }
+
+    cacheInitialised_ = true;
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::solidBodyFvGeometryScheme::solidBodyFvGeometryScheme
+(
+    const fvMesh& mesh,
+    const dictionary& dict
+)
+:
+    basicFvGeometryScheme(mesh, dict),
+    partialUpdate_(dict.getOrDefault<bool>("partialUpdate", true)),
+    cacheMotion_(dict.getOrDefault<bool>("cacheMotion", true)),
+    cacheInitialised_(false),
+    changedFaceIDs_(),
+    changedPatchIDs_(),
+    changedCellIDs_()
+{
+    DebugInFunction
+        << "partialUpdate:" << partialUpdate_
+        << " cacheMotion:" << cacheMotion_
+        << endl;
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::solidBodyFvGeometryScheme::movePoints()
+{
+    // Note: not calling fvGeometryScheme::movePoints since we want to perform
+    // our own geometry manipulations
+
+    bool haveGeometry =
+        mesh_.hasCellCentres()
+     && mesh_.hasFaceCentres()
+     && mesh_.hasCellVolumes()
+     && mesh_.hasFaceAreas();
+
+    if (!haveGeometry)
+    {
+        DebugInFunction
+            << "Creating initial geometry using primitiveMesh::updateGeom"
+            << endl;
+
+        const_cast<fvMesh&>(mesh_).primitiveMesh::updateGeom();
+        return;
+    }
+
+    if (mesh_.moving())
+    {
+        setMeshMotionData();
+
+        DebugInFunction << "Performing partial meshPhi construction" << endl;
+
+        const pointField& oldPoints = mesh_.oldPoints();
+        const pointField& currPoints = mesh_.points();
+
+        if (oldPoints.size() != currPoints.size())
+        {
+            FatalErrorInFunction
+                << "Old and current points sizes must be the same. "
+                << "Old points:" << oldPoints.size()
+                << " Current points:" << currPoints.size()
+                << abort(FatalError);
+        }
+
+        const polyBoundaryMesh& pbm = mesh_.boundaryMesh();
+        const faceList& faces = mesh_.faces();
+        const scalar rdt = 1.0/mesh_.time().deltaTValue();
+
+        // Set the mesh flux
+        auto& meshPhi = const_cast<fvMesh&>(mesh_).setPhi();
+        auto& meshPhii = meshPhi.primitiveFieldRef();
+        auto& meshPhiBf = meshPhi.boundaryFieldRef();
+
+        //meshPhi == dimensionedScalar(dimVolume/dimTime, Zero);
+        meshPhii = Zero;
+        meshPhiBf == Zero;
+
+        forAll(changedFaceIDs_, i)
+        {
+            const face& f = faces[changedFaceIDs_[i]];
+
+            if (changedPatchIDs_[i] == -1)
+            {
+                const label facei = changedFaceIDs_[i];
+                meshPhii[facei] = f.sweptVol(oldPoints, currPoints)*rdt;
+            }
+            else
+            {
+                const label patchi = changedPatchIDs_[i];
+                const polyPatch& pp = pbm[patchi];
+
+                if (isA<emptyPolyPatch>(pp))
+                {
+                    continue;
+                }
+
+                const label patchFacei = changedFaceIDs_[i] - pp.start();
+
+                meshPhiBf[patchi][patchFacei] =
+                    f.sweptVol(oldPoints, currPoints)*rdt;
+            }
+        }
+
+        if (partialUpdate_ && haveGeometry)
+        {
+            // Keep base geometry and update as needed
+            DebugInFunction << "Performing partial geometry update" << endl;
+
+            // Initialise geometry using the old/existing values
+            vectorField faceCentres(mesh_.faceCentres());
+            vectorField faceAreas(mesh_.faceAreas());
+
+            // Make face centres and areas consistent with new points
+            primitiveMeshTools::updateFaceCentresAndAreas
+            (
+                mesh_,
+                changedFaceIDs_,
+                mesh_.points(),
+                faceCentres,
+                faceAreas
+            );
+
+            vectorField cellCentres(mesh_.cellCentres());
+            scalarField cellVolumes(mesh_.cellVolumes());
+
+            primitiveMeshTools::updateCellCentresAndVols
+            (
+                mesh_,
+                faceCentres,
+                faceAreas,
+                changedCellIDs_,
+                mesh_.cells(),
+                cellCentres,
+                cellVolumes
+            );
+
+            const_cast<fvMesh&>(mesh_).primitiveMesh::resetGeometry
+            (
+                std::move(faceCentres),
+                std::move(faceAreas),
+                std::move(cellCentres),
+                std::move(cellVolumes)
+            );
+
+            if (debug)
+            {
+                for (const auto& p : mesh_.boundaryMesh())
+                {
+                    Pout<< "SBM --- " << p.name()
+                        << " sum(Sf)=" << sum(p.faceAreas())
+                        << " sum(mag(Sf))=" << sum(mag(p.faceAreas()))
+                        << endl;
+                }
+            }
+        }
+        else
+        {
+            DebugInFunction
+                << "Performing complete geometry clear and update" << endl;
+
+            // Clear out old geometry
+            // Note: this recreates the old primitiveMesh::movePoints behaviour
+            const_cast<fvMesh&>(mesh_).primitiveMesh::clearGeom();
+
+            // Use lower level to calculate the geometry
+            const_cast<fvMesh&>(mesh_).primitiveMesh::updateGeom();
+        }
+    }
+    else
+    {
+        DebugInFunction << "Performing complete geometry update" << endl;
+
+        // Use lower level to calculate the geometry
+        const_cast<fvMesh&>(mesh_).primitiveMesh::updateGeom();
+    }
+}
+
+
+void Foam::solidBodyFvGeometryScheme::updateMesh(const mapPolyMesh& mpm)
+{
+    cacheInitialised_ = false;
+}
+
+
+// ************************************************************************* //
diff --git a/src/finiteVolume/fvMesh/fvGeometryScheme/solidBody/solidBodyFvGeometryScheme.H b/src/finiteVolume/fvMesh/fvGeometryScheme/solidBody/solidBodyFvGeometryScheme.H
new file mode 100644
index 0000000000..755f21080b
--- /dev/null
+++ b/src/finiteVolume/fvMesh/fvGeometryScheme/solidBody/solidBodyFvGeometryScheme.H
@@ -0,0 +1,141 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2021-2022 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::solidBodyFvGeometryScheme
+
+Description
+    Geometry calculation scheme that performs geometry updates only in regions
+    where the mesh has changed.
+
+    Example usage in fvSchemes:
+
+    \verbatim
+        geometry
+        {
+            type            solidBody;
+
+            // Optional entries
+
+            // If set to false, update the entire mesh
+            partialUpdate   yes;
+
+            // Cache the motion addressing (changed points, faces, cells etc)
+            cacheMotion     yes;
+        }
+    \endverbatim
+
+
+SourceFiles
+    solidBodyFvGeometryScheme.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef solidBodyFvGeometryScheme_H
+#define solidBodyFvGeometryScheme_H
+
+#include "basicFvGeometryScheme.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                  Class solidBodyFvGeometryScheme Declaration
+\*---------------------------------------------------------------------------*/
+
+class solidBodyFvGeometryScheme
+:
+    public basicFvGeometryScheme
+{
+    // Private Data
+
+        //- Partial update flag
+        bool partialUpdate_;
+
+        //- Cache mesh motion flag
+        bool cacheMotion_;
+
+        //- Flag to indicate that the cache has been initialised
+        bool cacheInitialised_;
+
+        //- Changed face IDs
+        labelList changedFaceIDs_;
+
+        //- Changed patch IDs
+        labelList changedPatchIDs_;
+
+        //- Changed cell IDs
+        labelList changedCellIDs_;
+
+
+    // Private Member Functions
+
+        //- Set the mesh motion data (point, face IDs)
+        void setMeshMotionData();
+
+        //- No copy construct
+        solidBodyFvGeometryScheme(const solidBodyFvGeometryScheme&) = delete;
+
+        //- No copy assignment
+        void operator=(const solidBodyFvGeometryScheme&) = delete;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("solidBody");
+
+
+    // Constructors
+
+        //- Construct from mesh
+        solidBodyFvGeometryScheme(const fvMesh& mesh, const dictionary& dict);
+
+
+    //- Destructor
+    virtual ~solidBodyFvGeometryScheme() = default;
+
+
+    // Member Functions
+
+        //- Do what is necessary if the mesh has moved
+        virtual void movePoints();
+
+        //- Update mesh for topology changes
+        virtual void updateMesh(const mapPolyMesh& mpm);
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //