leastSquaresGrad.C

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License
    This file is part of OpenFOAM.
 
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    under the terms of the GNU General Public License as published by
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    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 "leastSquaresGrad.H"
#include "leastSquaresVectors.H"
#include "gaussGrad.H"
#include "fvMesh.H"
#include "GeometricField.H"
#include "extrapolatedCalculatedFvPatchField.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
template<class Type>
Foam::tmp
<
    Foam::VolField<typename Foam::outerProduct<Foam::vector, Type>::type>
>
Foam::fv::leastSquaresGrad<Type>::calcGrad
(
    const VolField<Type>& vsf,
    const word& name
) const
{
    typedef typename outerProduct<vector, Type>::type GradType;
 
    const fvMesh& mesh = vsf.mesh();
 
    tmp<VolField<GradType>> tlsGrad
    (
        VolField<GradType>::New
        (
            name,
            mesh,
            dimensioned<GradType>
            (
                "zero",
                vsf.dimensions()/dimLength,
                Zero
            ),
            extrapolatedCalculatedFvPatchField<GradType>::typeName
        )
    );
    VolField<GradType>& lsGrad = tlsGrad.ref();
 
    // Get reference to least square vectors
    const leastSquaresVectors& lsv = leastSquaresVectors::New(mesh);
 
    const surfaceVectorField& ownLs = lsv.pVectors();
    const surfaceVectorField& neiLs = lsv.nVectors();
 
    const labelUList& own = mesh.owner();
    const labelUList& nei = mesh.neighbour();
 
    forAll(own, facei)
    {
        label ownFacei = own[facei];
        label neiFacei = nei[facei];
 
        Type deltaVsf = vsf[neiFacei] - vsf[ownFacei];
 
        lsGrad[ownFacei] += ownLs[facei]*deltaVsf;
        lsGrad[neiFacei] -= neiLs[facei]*deltaVsf;
    }
 
    // Boundary faces
    forAll(vsf.boundaryField(), patchi)
    {
        const fvsPatchVectorField& patchOwnLs = ownLs.boundaryField()[patchi];
 
        const labelUList& faceCells =
            vsf.boundaryField()[patchi].patch().faceCells();
 
        if (vsf.boundaryField()[patchi].coupled())
        {
            const Field<Type> neiVsf
            (
                vsf.boundaryField()[patchi].patchNeighbourField()
            );
 
            forAll(neiVsf, patchFacei)
            {
                lsGrad[faceCells[patchFacei]] +=
                    patchOwnLs[patchFacei]
                   *(neiVsf[patchFacei] - vsf[faceCells[patchFacei]]);
            }
        }
        else
        {
            const fvPatchField<Type>& patchVsf = vsf.boundaryField()[patchi];
 
            forAll(patchVsf, patchFacei)
            {
                lsGrad[faceCells[patchFacei]] +=
                     patchOwnLs[patchFacei]
                    *(patchVsf[patchFacei] - vsf[faceCells[patchFacei]]);
            }
        }
    }
 
 
    lsGrad.correctBoundaryConditions();
    gaussGrad<Type>::correctBoundaryConditions(vsf, lsGrad);
 
    return tlsGrad;
}
 
 
// ************************************************************************* //