LiaoBase.C

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#include "LiaoBase.H"
#include "fvcGrad.H"

// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::diameterModels::LiaoBase::LiaoBase
(
    const populationBalanceModel& popBal,
    const dictionary& dict
)
:
    populationBalance_(popBal),
    kolmogorovLengthScale_
    (
        IOobject
        (
            "kolmogorovLengthScale",
            populationBalance_.time().timeName(),
            populationBalance_.mesh()
        ),
        populationBalance_.mesh(),
        dimensionedScalar
        (
            "kolmogorovLengthScale",
            dimLength,
            Zero
        )
    ),
    shearStrainRate_
    (
        IOobject
        (
            "shearStrainRate",
            populationBalance_.time().timeName(),
            populationBalance_.mesh()
        ),
        populationBalance_.mesh(),
        dimensionedScalar
        (
            "shearStrainRate",
            dimVelocity/dimLength,
            Zero
        )
    ),
    eddyStrainRate_
    (
        IOobject
        (
            "eddyStrainRate",
            populationBalance_.time().timeName(),
            populationBalance_.mesh()
        ),
        populationBalance_.mesh(),
        dimensionedScalar
        (
            "eddyStrainRate",
            dimVelocity/dimLength,
            Zero
        )
    )
{}


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

void Foam::diameterModels::LiaoBase::precompute()
{
    kolmogorovLengthScale_ =
        pow025
        (
            pow3(populationBalance_.continuousPhase().thermo().nu())
           /populationBalance_.continuousTurbulence().epsilon()
        );

    shearStrainRate_ =
        sqrt(2.0)
       *mag(symm(fvc::grad(populationBalance_.continuousPhase().U())));

    eddyStrainRate_ =
           sqrt
           (
               populationBalance_.continuousPhase().rho()
              *populationBalance_.continuousTurbulence().epsilon()
              /populationBalance_.continuousPhase().thermo().mu()
           );

    if (uTerminal_.empty())
    {
        const fvMesh& mesh = populationBalance_.mesh();
        const uniformDimensionedVectorField& g =
            mesh.lookupObject<uniformDimensionedVectorField>("g");

        const dimensionedScalar nuc
        (
            "nuc",
            dimViscosity,
            gAverage(populationBalance_.continuousPhase().thermo().nu()())
        );

        const dimensionedScalar rhoc
        (
            "rhoc",
            dimDensity,
            gAverage(populationBalance_.continuousPhase().rho()())
        );

        const dimensionedScalar rhod
        (
            "rhod",
            dimDensity,
            gAverage(populationBalance_.sizeGroups()[1].phase().rho()())
        );

        const dimensionedScalar sigma
        (
            "sigma",
            dimForce/dimLength,
            gAverage
            (
                populationBalance_.sigmaWithContinuousPhase
                (
                    populationBalance_.sizeGroups()[1].phase()
                )()
            )
        );

        for(int m = 0; m < populationBalance_.sizeGroups().size(); m++)
        {
            const sizeGroup& f = populationBalance_.sizeGroups()[m];

            dimensionedScalar uTerminal("uTerminal", dimVelocity, 0.2);
            dimensionedScalar Cd("Cd", dimless, 0.44);
            dimensionedScalar CdEllipse("CdEllipse", dimless, 1);

            dimensionedScalar Re(uTerminal*f.dSph()/nuc);
            const dimensionedScalar Eo
            (
                mag(g)*mag(rhoc - rhod)*sqr(f.dSph())/sigma
            );

            dimensionedScalar F("F", dimForce/dimArea, 1);
            dimensionedScalar dF("dF", dimForce/dimArea/dimVelocity, 1);
            const dimensionedScalar uTerminalX("uTerminalX", dimVelocity, 1e-5);
            dimensionedScalar ReX("ReX", dimless, Re.value());
            dimensionedScalar CdX("CdX", dimless, Cd.value());
            dimensionedScalar dCd("dCd", Cd.dimensions()/dimVelocity, Zero);

            int n = 0;

            while(mag(F.value()) >= 1.0e-05 && n++ <= 20)
            {
                Re = uTerminal*f.dSph()/nuc;

                Cd =
                    pos0(1000 - Re)*24/Re*(1 + 0.1*pow(Re, 0.75))
                  + neg(1000 - Re)*0.44;

                CdEllipse = 0.6666*sqrt(Eo);

                Cd =
                    pos0(CdEllipse - Cd)
                   *min(CdEllipse.value(), 8.0/3.0)
                  + neg(CdEllipse - Cd)*Cd;

                F =
                    4.0/3.0*(rhoc - rhod)*mag(g)*f.dSph()
                  - rhoc*Cd*sqr(uTerminal);

                ReX = (uTerminal + uTerminalX)*f.dSph()/nuc;

                CdX =
                    pos0(1000 - ReX)
                   *24/ReX*(1 + 0.1*pow(ReX, 0.75))
                  + neg(1000 - ReX)*0.44;

                CdX =
                    pos0(CdEllipse - CdX)
                   *min(CdEllipse.value(), 2.66667)
                  + neg(CdEllipse - CdX)*CdX;

                dCd = (CdX - Cd)/uTerminalX;

                dF = -(2*rhoc*uTerminal*Cd + rhoc*sqr(uTerminal)*dCd);

                uTerminal -= F/dF;
            }

            uTerminal_.append(new dimensionedScalar("uTerminal", uTerminal));

            Cd_.append(new dimensionedScalar("Cd", Cd));
        }
    }
}


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