multiphaseVoFMixture.C

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License
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#include "multiphaseVoFMixture.H"
#include "correctContactAngle.H"
#include "surfaceInterpolate.H"
#include "fvcGrad.H"
#include "fvcSnGrad.H"
#include "fvcDiv.H"
 
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
namespace Foam
{
    defineTypeNameAndDebug(multiphaseVoFMixture, 0);
}
 
 
// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
void Foam::multiphaseVoFMixture::calcAlphas()
{
    scalar level = 0.0;
    alphas_ == 0.0;
 
    forAll(phases_, phasei)
    {
        alphas_ += level*phases_[phasei];
        level += 1.0;
    }
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
Foam::multiphaseVoFMixture::multiphaseVoFMixture
(
    const fvMesh& mesh,
    const VoFphase::iNew& inew
)
:
    VoFMixture(mesh),
    IOdictionary
    (
        IOobject
        (
            "phaseProperties",
            mesh.time().constant(),
            mesh,
            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    ),
 
    phases_(lookup("phases"), inew),
 
    mesh_(mesh),
 
    alphas_
    (
        IOobject
        (
            "alphas",
            mesh_.time().name(),
            mesh_,
            IOobject::NO_READ,
            IOobject::AUTO_WRITE
        ),
        mesh_,
        dimensionedScalar(dimless, 0)
    ),
 
    sigmas_(lookup("sigmas")),
    dimSigma_(1, 0, -2, 0, 0),
 
    deltaN_
    (
        "deltaN",
        1e-8/pow(average(mesh_.V()), 1.0/3.0)
    )
{
    calcAlphas();
    alphas_.write();
}
 
 
// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
Foam::tmp<Foam::surfaceScalarField>
Foam::multiphaseVoFMixture::surfaceTensionForce(const volVectorField& U) const
{
    tmp<surfaceScalarField> tstf
    (
        surfaceScalarField::New
        (
            "surfaceTensionForce",
            mesh_,
            dimensionedScalar(dimensionSet(1, -2, -2, 0, 0), 0)
        )
    );
 
    surfaceScalarField& stf = tstf.ref();
 
    forAll(phases_, phasei)
    {
        const VoFphase& alpha1 = phases_[phasei];
 
        for (label phasej = phasei+1; phasej<phases_.size(); phasej++)
        {
            const VoFphase& alpha2 = phases_[phasej];
 
            sigmaTable::const_iterator sigma =
                sigmas_.find(interfacePair(alpha1, alpha2));
 
            if (sigma == sigmas_.end())
            {
                FatalErrorInFunction
                    << "Cannot find interface " << interfacePair(alpha1, alpha2)
                    << " in list of sigma values"
                    << exit(FatalError);
            }
 
            stf += dimensionedScalar(dimSigma_, sigma())
               *fvc::interpolate(K(alpha1, alpha2, U))*
                (
                    fvc::interpolate(alpha2)*fvc::snGrad(alpha1)
                  - fvc::interpolate(alpha1)*fvc::snGrad(alpha2)
                );
        }
    }
 
    return tstf;
}
 
 
Foam::tmp<Foam::surfaceVectorField> Foam::multiphaseVoFMixture::nHatfv
(
    const volScalarField& alpha1,
    const volScalarField& alpha2
) const
{
    /*
    // Cell gradient of alpha
    volVectorField gradAlpha =
        alpha2*fvc::grad(alpha1) - alpha1*fvc::grad(alpha2);
 
    // Interpolated face-gradient of alpha
    surfaceVectorField gradAlphaf = fvc::interpolate(gradAlpha);
    */
 
    surfaceVectorField gradAlphaf
    (
        fvc::interpolate(alpha2)*fvc::interpolate(fvc::grad(alpha1))
      - fvc::interpolate(alpha1)*fvc::interpolate(fvc::grad(alpha2))
    );
 
    // Face unit interface normal
    return gradAlphaf/(mag(gradAlphaf) + deltaN_);
}
 
 
Foam::tmp<Foam::surfaceScalarField> Foam::multiphaseVoFMixture::nHatf
(
    const volScalarField& alpha1,
    const volScalarField& alpha2
) const
{
    // Face unit interface normal flux
    return nHatfv(alpha1, alpha2) & mesh_.Sf();
}
 
 
Foam::tmp<Foam::volScalarField> Foam::multiphaseVoFMixture::K
(
    const VoFphase& alpha1,
    const VoFphase& alpha2,
    const volVectorField& U
) const
{
    tmp<surfaceVectorField> tnHatfv = nHatfv(alpha1, alpha2);
 
    correctContactAngle
    (
        alpha1,
        alpha2,
        U.boundaryField(),
        deltaN_,
        tnHatfv.ref().boundaryFieldRef()
    );
 
    // Simple expression for curvature
    return -fvc::div(tnHatfv & mesh_.Sf());
}
 
 
Foam::tmp<Foam::volScalarField>
Foam::multiphaseVoFMixture::nearInterface() const
{
    tmp<volScalarField> tnearInt
    (
        volScalarField::New
        (
            "nearInterface",
            mesh_,
            dimensionedScalar(dimless, 0)
        )
    );
 
    forAll(phases_, phasei)
    {
        tnearInt.ref() = max
        (
            tnearInt(),
            pos0(phases_[phasei] - 0.01)*pos0(0.99 - phases_[phasei])
        );
    }
 
    return tnearInt;
}
 
 
bool Foam::multiphaseVoFMixture::read()
{
    if (regIOobject::read())
    {
        lookup("sigmas") >> sigmas_;
        return true;
    }
    else
    {
        return false;
    }
}
 
 
// ************************************************************************* //