cellModel.C

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  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
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#include "cellModel.H"
#include <OpenFOAM/pyramid.H>

// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

Foam::vector Foam::cellModel::centre
(
    const labelList& pointLabels,
    const pointField& points
) const
{
    // Estimate centre of cell
    vector cEst = vector::zero;

    // Sum the points idicated by the label list
    forAll(pointLabels, i)
    {
        cEst += points[pointLabels[i]];
    }

    // Average by dividing by the number summed over.
    cEst /= scalar(pointLabels.size());


    // Calculate the centre by breaking the cell into pyramids and
    // volume-weighted averaging their centres
    scalar sumV = 0.0;
    vector sumVc = vector::zero;

    const faceList cellFaces = faces(pointLabels);

    forAll(cellFaces, i)
    {
        const face& curFace = cellFaces[i];

        scalar pyrVol =
            pyramid<point, const point&, const face&>
            (
                curFace,
                cEst
            ).mag(points);

        if (pyrVol > SMALL)
        {
            WarningIn("cellModel::centre(const labelList&, const pointField&)")
                << "zero or negative pyramid volume: " << -pyrVol
                << " for face " << i
                << endl;
        }

        sumVc -=
            pyrVol
           *pyramid<point, const point&, const face&>(curFace, cEst)
           .centre(points);

        sumV -= pyrVol;
    }

    return sumVc/(sumV + VSMALL);
}


Foam::scalar Foam::cellModel::mag
(
    const labelList& pointLabels,
    const pointField& points
) const
{
    // Estimate centre of cell
    vector cEst = vector::zero;

    // Sum the points idicated by the label list
    forAll(pointLabels, i)
    {
        cEst += points[pointLabels[i]];
    }

    // Average by dividing by the number summed over.
    cEst /= scalar(pointLabels.size());


    // Calculate the magnitude by summing the -mags of the pyramids
    // The sign change is because the faces point outwards
    // and a pyramid is constructed from an inward pointing face
    // and the base centre-apex vector
    scalar v = 0;

    const faceList cellFaces = faces(pointLabels);

    forAll(cellFaces, i)
    {
        const face& curFace =cellFaces[i];

        scalar pyrVol =
            pyramid<point, const point&, const face&>
            (
                curFace,
                cEst
            ).mag(points);

        if (pyrVol > SMALL)
        {
            WarningIn("cellModel::mag(const labelList&, const pointField&)")
                << "zero or negative pyramid volume: " << -pyrVol
                << " for face " << i
                << endl;
        }

        v -= pyrVol;
    }

    return v;
}

// ************************ vim: set sw=4 sts=4 et: ************************ //