mapLagrangian.C

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    Copyright (C) 2011-2017 OpenFOAM Foundation
    Copyright (C) 2018-2019 OpenCFD Ltd.
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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.
 
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    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
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#include "MapLagrangianFields.H"
#include "passiveParticleCloud.H"
#include "meshSearch.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
static const scalar perturbFactor = 1e-6;
 
 
// Special version of findCell that generates a cell guaranteed to be
// compatible with tracking.
static label findCell(const Cloud<passiveParticle>& cloud, const point& pt)
{
    label celli = -1;
    label tetFacei = -1;
    label tetPtI = -1;
 
    const polyMesh& mesh = cloud.pMesh();
 
    mesh.findCellFacePt(pt, celli, tetFacei, tetPtI);
 
    if (celli >= 0)
    {
        return celli;
    }
    else
    {
        // See if particle on face by finding nearest face and shifting
        // particle.
 
        meshSearch meshSearcher
        (
            mesh,
            polyMesh::FACE_PLANES    // no decomposition needed
        );
 
        label facei = meshSearcher.findNearestBoundaryFace(pt);
 
        if (facei >= 0)
        {
            const point& cc = mesh.cellCentres()[mesh.faceOwner()[facei]];
 
            const point perturbPt = (1-perturbFactor)*pt+perturbFactor*cc;
 
            mesh.findCellFacePt(perturbPt, celli, tetFacei, tetPtI);
 
            return celli;
        }
    }
 
    return -1;
}
 
 
void mapLagrangian(const meshToMesh0& meshToMesh0Interp)
{
    // Determine which particles are in meshTarget
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
    // Target to source cell map
    const labelList& cellAddressing = meshToMesh0Interp.cellAddressing();
 
    // Invert celladdressing to get source to target(s).
    // Note: could use sparse addressing but that is too storage inefficient
    // (Map<labelList>)
    const labelListList sourceToTargets
    (
        invertOneToMany(meshToMesh0Interp.fromMesh().nCells(), cellAddressing)
    );
 
    const fvMesh& meshSource = meshToMesh0Interp.fromMesh();
    const fvMesh& meshTarget = meshToMesh0Interp.toMesh();
 
    const fileNameList cloudDirs
    (
        readDir
        (
            meshSource.time().timePath()/cloud::prefix,
            fileName::DIRECTORY
        )
    );
 
    for (const fileName& cloudDir : cloudDirs)
    {
        // Search for list of lagrangian objects for this time
        IOobjectList objects
        (
            meshSource,
            meshSource.time().timeName(),
            cloud::prefix/cloudDir
        );
 
        if (objects.found("coordinates") || objects.found("positions"))
        {
            // Has coordinates/positions - so must be a valid cloud
            Info<< nl << "    processing cloud " << cloudDir << endl;
 
            // Read positions & cell
            passiveParticleCloud sourceParcels
            (
                meshSource,
                cloudDir,
                false
            );
 
            Info<< "    read " << sourceParcels.size()
                << " parcels from source mesh." << endl;
 
            // Construct empty target cloud
            passiveParticleCloud targetParcels
            (
                meshTarget,
                Foam::zero{},
                cloudDir
            );
 
            passiveParticle::trackingData td(targetParcels);
 
            label sourceParticleI = 0;
 
            // Indices of source particles that get added to targetParcels
            DynamicList<label> addParticles(sourceParcels.size());
 
            // Unmapped particles
            labelHashSet unmappedSource(sourceParcels.size());
 
 
            // Initial: track from fine-mesh cell centre to particle position
            // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            // This requires there to be no boundary in the way.
 
 
            for (const passiveParticle& p : sourceParcels)
            {
                bool foundCell = false;
 
                // Assume that cell from read parcel is the correct one...
                if (p.cell() >= 0)
                {
                    const labelList& targetCells =
                        sourceToTargets[p.cell()];
 
                    // Particle probably in one of the targetcells. Try
                    // all by tracking from their cell centre to the parcel
                    // position.
 
                    for (const label targetCell : targetCells)
                    {
                        // Track from its cellcentre to position to make sure.
                        autoPtr<passiveParticle> newPtr
                        (
                            new passiveParticle
                            (
                                meshTarget,
                                barycentric(1, 0, 0, 0),
                                targetCell,
                                meshTarget.cells()[targetCell][0],
                                1
                            )
                        );
                        passiveParticle& newP = newPtr();
 
                        newP.track(p.position() - newP.position(), 0);
 
                        if (!newP.onFace())
                        {
                            // Hit position.
                            foundCell = true;
                            addParticles.append(sourceParticleI);
                            targetParcels.addParticle(newPtr.ptr());
                            break;
                        }
                    }
                }
 
                if (!foundCell)
                {
                    // Store for closer analysis
                    unmappedSource.insert(sourceParticleI);
                }
 
                sourceParticleI++;
            }
 
            Info<< "    after meshToMesh0 addressing found "
                << targetParcels.size()
                << " parcels in target mesh." << endl;
 
 
            // Do closer inspection for unmapped particles
            // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
            if (unmappedSource.size())
            {
                sourceParticleI = 0;
 
                for (passiveParticle& p : sourceParcels)
                {
                    if (unmappedSource.found(sourceParticleI))
                    {
                        const label targetCell =
                            findCell(targetParcels, p.position());
 
                        if (targetCell >= 0)
                        {
                            unmappedSource.erase(sourceParticleI);
                            addParticles.append(sourceParticleI);
                            targetParcels.addParticle
                            (
                                new passiveParticle
                                (
                                    meshTarget,
                                    p.position(),
                                    targetCell
                                )
                            );
                            sourceParcels.remove(&p);
                        }
                    }
                    sourceParticleI++;
                }
            }
            addParticles.shrink();
 
            Info<< "    after additional mesh searching found "
                << targetParcels.size() << " parcels in target mesh." << endl;
 
            if (addParticles.size())
            {
                IOPosition<passiveParticleCloud>(targetParcels).write();
 
                // addParticles now contains the indices of the sourceMesh
                // particles that were appended to the target mesh.
 
                // Map lagrangian fields
                // ~~~~~~~~~~~~~~~~~~~~~
 
                MapLagrangianFields<label>
                (cloudDir, objects, meshToMesh0Interp, addParticles);
                MapLagrangianFields<scalar>
                (cloudDir, objects, meshToMesh0Interp, addParticles);
                MapLagrangianFields<vector>
                (cloudDir, objects, meshToMesh0Interp, addParticles);
                MapLagrangianFields<sphericalTensor>
                (cloudDir, objects, meshToMesh0Interp, addParticles);
                MapLagrangianFields<symmTensor>
                (cloudDir, objects, meshToMesh0Interp, addParticles);
                MapLagrangianFields<tensor>
                (cloudDir, objects, meshToMesh0Interp, addParticles);
            }
        }
    }
}
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// ************************************************************************* //