CrossPowerLaw.C

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#include "CrossPowerLaw.H"
#include "volFields.H"
#include "addToRunTimeSelectionTable.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
namespace laminarModels
{
namespace generalisedNewtonianViscosityModels
{
    defineTypeNameAndDebug(CrossPowerLaw, 0);

    addToRunTimeSelectionTable
    (
        generalisedNewtonianViscosityModel,
        CrossPowerLaw,
        dictionary
    );
}
}
}


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

Foam::laminarModels::generalisedNewtonianViscosityModels::CrossPowerLaw::
CrossPowerLaw
(
    const dictionary& viscosityProperties
)
:
    generalisedNewtonianViscosityModel(viscosityProperties),
    nuInf_("nuInf", dimViscosity, 0),
    m_("m", dimTime, 0),
    tauStar_( "tauStar", dimViscosity/dimTime, 0),
    n_("n", dimless, 0)
{
    read(viscosityProperties);
}


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

bool Foam::laminarModels::generalisedNewtonianViscosityModels::CrossPowerLaw::
read
(
    const dictionary& viscosityProperties
)
{
    generalisedNewtonianViscosityModel::read(viscosityProperties);

    const dictionary& coeffs =
        viscosityProperties.optionalSubDict(typeName + "Coeffs");

    coeffs.lookup("nuInf") >> nuInf_;

    if (coeffs.found("tauStar"))
    {
        coeffs.lookup("tauStar") >> tauStar_;
    }
    else
    {
        coeffs.lookup("m") >> m_;
    }

    coeffs.lookup("n") >> n_;

    return true;
}


Foam::tmp<Foam::volScalarField>
Foam::laminarModels::generalisedNewtonianViscosityModels::CrossPowerLaw::
nu
(
    const volScalarField& nu0,
    const volScalarField& strainRate
) const
{
    return
       nuInf_
     + (nu0 - nuInf_)
       /(
           scalar(1)
         + pow
           (
                tauStar_.value() > 0
              ? nu0*strainRate/tauStar_
              : m_*strainRate,
                n_
            )
        );
}


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