faceLimitedGrads.C

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#include "faceLimitedGrad.H"
#include <finiteVolume/gaussGrad.H>
#include <finiteVolume/fvMesh.H>
#include <finiteVolume/volMesh.H>
#include <finiteVolume/surfaceMesh.H>
#include <finiteVolume/volFields.H>
#include <finiteVolume/fixedValueFvPatchFields.H>

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace fv
{

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

makeFvGradScheme(faceLimitedGrad)

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

template<class Type>
inline void faceLimitedGrad<Type>::limitFace
(
    scalar& limiter,
    const scalar maxDelta,
    const scalar minDelta,
    const scalar extrapolate
) const
{
    if (extrapolate > maxDelta + VSMALL)
    {
        limiter = min(limiter, maxDelta/extrapolate);
    }
    else if (extrapolate < minDelta - VSMALL)
    {
        limiter = min(limiter, minDelta/extrapolate);
    }
}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

template<>
tmp<volVectorField> faceLimitedGrad<scalar>::grad
(
    const volScalarField& vsf
) const
{
    const fvMesh& mesh = vsf.mesh();

    tmp<volVectorField> tGrad = basicGradScheme_().grad(vsf);

    if (k_ < SMALL)
    {
        return tGrad;
    }

    volVectorField& g = tGrad();

    const unallocLabelList& owner = mesh.owner();
    const unallocLabelList& neighbour = mesh.neighbour();

    const volVectorField& C = mesh.C();
    const surfaceVectorField& Cf = mesh.Cf();

    // create limiter
    scalarField limiter(vsf.internalField().size(), 1.0);

    scalar rk = (1.0/k_ - 1.0);

    forAll(owner, facei)
    {
        label own = owner[facei];
        label nei = neighbour[facei];

        scalar vsfOwn = vsf[own];
        scalar vsfNei = vsf[nei];

        scalar maxFace = max(vsfOwn, vsfNei);
        scalar minFace = min(vsfOwn, vsfNei);
        scalar maxMinFace = rk*(maxFace - minFace);
        maxFace += maxMinFace;
        minFace -= maxMinFace;

        // owner side
        limitFace
        (
            limiter[own],
            maxFace - vsfOwn, minFace - vsfOwn,
            (Cf[facei] - C[own]) & g[own]
        );

        // neighbour side
        limitFace
        (
            limiter[nei],
            maxFace - vsfNei, minFace - vsfNei,
            (Cf[facei] - C[nei]) & g[nei]
        );
    }

    const volScalarField::GeometricBoundaryField& bsf = vsf.boundaryField();

    forAll(bsf, patchi)
    {
        const fvPatchScalarField& psf = bsf[patchi];

        const unallocLabelList& pOwner = mesh.boundary()[patchi].faceCells();
        const vectorField& pCf = Cf.boundaryField()[patchi];

        if (psf.coupled())
        {
            scalarField psfNei = psf.patchNeighbourField();

            forAll(pOwner, pFacei)
            {
                label own = pOwner[pFacei];

                scalar vsfOwn = vsf[own];
                scalar vsfNei = psfNei[pFacei];

                scalar maxFace = max(vsfOwn, vsfNei);
                scalar minFace = min(vsfOwn, vsfNei);
                scalar maxMinFace = rk*(maxFace - minFace);
                maxFace += maxMinFace;
                minFace -= maxMinFace;

                limitFace
                (
                    limiter[own],
                    maxFace - vsfOwn, minFace - vsfOwn,
                    (pCf[pFacei] - C[own]) & g[own]
                );
            }
        }
        else if (psf.fixesValue())
        {
            forAll(pOwner, pFacei)
            {
                label own = pOwner[pFacei];

                scalar vsfOwn = vsf[own];
                scalar vsfNei = psf[pFacei];

                scalar maxFace = max(vsfOwn, vsfNei);
                scalar minFace = min(vsfOwn, vsfNei);
                scalar maxMinFace = rk*(maxFace - minFace);
                maxFace += maxMinFace;
                minFace -= maxMinFace;

                limitFace
                (
                    limiter[own],
                    maxFace - vsfOwn, minFace - vsfOwn,
                    (pCf[pFacei] - C[own]) & g[own]
                );
            }
        }
    }

    if (fv::debug)
    {
        Info<< "gradient limiter for: " << vsf.name()
            << " max = " << gMax(limiter)
            << " min = " << gMin(limiter)
            << " average: " << gAverage(limiter) << endl;
    }

    g.internalField() *= limiter;
    g.correctBoundaryConditions();
    gaussGrad<scalar>::correctBoundaryConditions(vsf, g);

    return tGrad;
}


template<>
tmp<volTensorField> faceLimitedGrad<vector>::grad
(
    const volVectorField& vvf
) const
{
    const fvMesh& mesh = vvf.mesh();

    tmp<volTensorField> tGrad = basicGradScheme_().grad(vvf);

    if (k_ < SMALL)
    {
        return tGrad;
    }

    volTensorField& g = tGrad();

    const unallocLabelList& owner = mesh.owner();
    const unallocLabelList& neighbour = mesh.neighbour();

    const volVectorField& C = mesh.C();
    const surfaceVectorField& Cf = mesh.Cf();

    // create limiter
    scalarField limiter(vvf.internalField().size(), 1.0);

    scalar rk = (1.0/k_ - 1.0);

    forAll(owner, facei)
    {
        label own = owner[facei];
        label nei = neighbour[facei];

        vector vvfOwn = vvf[own];
        vector vvfNei = vvf[nei];

        // owner side
        vector gradf = (Cf[facei] - C[own]) & g[own];

        scalar vsfOwn = gradf & vvfOwn;
        scalar vsfNei = gradf & vvfNei;

        scalar maxFace = max(vsfOwn, vsfNei);
        scalar minFace = min(vsfOwn, vsfNei);
        scalar maxMinFace = rk*(maxFace - minFace);
        maxFace += maxMinFace;
        minFace -= maxMinFace;

        limitFace
        (
            limiter[own],
            maxFace - vsfOwn, minFace - vsfOwn,
            magSqr(gradf)
        );


        // neighbour side
        gradf = (Cf[facei] - C[nei]) & g[nei];

        vsfOwn = gradf & vvfOwn;
        vsfNei = gradf & vvfNei;

        maxFace = max(vsfOwn, vsfNei);
        minFace = min(vsfOwn, vsfNei);

        limitFace
        (
            limiter[nei],
            maxFace - vsfNei, minFace - vsfNei,
            magSqr(gradf)
        );
    }


    const volVectorField::GeometricBoundaryField& bvf = vvf.boundaryField();

    forAll(bvf, patchi)
    {
        const fvPatchVectorField& psf = bvf[patchi];

        const unallocLabelList& pOwner = mesh.boundary()[patchi].faceCells();
        const vectorField& pCf = Cf.boundaryField()[patchi];

        if (psf.coupled())
        {
            vectorField psfNei = psf.patchNeighbourField();

            forAll(pOwner, pFacei)
            {
                label own = pOwner[pFacei];

                vector vvfOwn = vvf[own];
                vector vvfNei = psfNei[pFacei];

                vector gradf = (pCf[pFacei] - C[own]) & g[own];

                scalar vsfOwn = gradf & vvfOwn;
                scalar vsfNei = gradf & vvfNei;

                scalar maxFace = max(vsfOwn, vsfNei);
                scalar minFace = min(vsfOwn, vsfNei);
                scalar maxMinFace = rk*(maxFace - minFace);
                maxFace += maxMinFace;
                minFace -= maxMinFace;

                limitFace
                (
                    limiter[own],
                    maxFace - vsfOwn, minFace - vsfOwn,
                    magSqr(gradf)
                );
            }
        }
        else if (psf.fixesValue())
        {
            forAll(pOwner, pFacei)
            {
                label own = pOwner[pFacei];

                vector vvfOwn = vvf[own];
                vector vvfNei = psf[pFacei];

                vector gradf = (pCf[pFacei] - C[own]) & g[own];

                scalar vsfOwn = gradf & vvfOwn;
                scalar vsfNei = gradf & vvfNei;

                scalar maxFace = max(vsfOwn, vsfNei);
                scalar minFace = min(vsfOwn, vsfNei);
                scalar maxMinFace = rk*(maxFace - minFace);
                maxFace += maxMinFace;
                minFace -= maxMinFace;

                limitFace
                (
                    limiter[own],
                    maxFace - vsfOwn, minFace - vsfOwn,
                    magSqr(gradf)
                );
            }
        }
    }

    if (fv::debug)
    {
        Info<< "gradient limiter for: " << vvf.name()
            << " max = " << gMax(limiter)
            << " min = " << gMin(limiter)
            << " average: " << gAverage(limiter) << endl;
    }

    g.internalField() *= limiter;
    g.correctBoundaryConditions();
    gaussGrad<vector>::correctBoundaryConditions(vvf, g);

    return tGrad;
}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace fv

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

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