BirdCarreau.C

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#include "BirdCarreau.H"
#include "addToRunTimeSelectionTable.H"
 
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
namespace Foam
{
namespace laminarModels
{
namespace generalisedNewtonianViscosityModels
{
    defineTypeNameAndDebug(BirdCarreau, 0);
    addToRunTimeSelectionTable
    (
        generalisedNewtonianViscosityModel,
        BirdCarreau,
        dictionary
    );
}
}
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
Foam::laminarModels::generalisedNewtonianViscosityModels::BirdCarreau::
BirdCarreau
(
    const dictionary& viscosityProperties,
    const Foam::viscosity& viscosity,
    const volVectorField& U
)
:
    strainRateViscosityModel(viscosityProperties, viscosity, U),
    nuInf_("nuInf", dimViscosity, 0),
    k_("k", dimTime, 0),
    tauStar_( "tauStar", dimViscosity/dimTime, 0),
    n_("n", dimless, 0),
    a_("a", dimless, 2)
{
    read(viscosityProperties);
    correct();
}
 
 
// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
bool Foam::laminarModels::generalisedNewtonianViscosityModels::BirdCarreau::
read
(
    const dictionary& viscosityProperties
)
{
    strainRateViscosityModel::read(viscosityProperties);
 
    const dictionary& coeffs =
        viscosityProperties.optionalSubDict(typeName + "Coeffs");
 
    nuInf_.read(coeffs);;
 
    if (coeffs.found("tauStar"))
    {
        tauStar_.read(coeffs);
    }
    else
    {
        k_.read(coeffs);
    }
 
    n_.read(coeffs);
    a_.readIfPresent(coeffs);
 
    return true;
}
 
 
Foam::tmp<Foam::volScalarField>
Foam::laminarModels::generalisedNewtonianViscosityModels::BirdCarreau::
nu
(
    const volScalarField& nu0,
    const volScalarField& strainRate
) const
{
    return
        nuInf_
      + (nu0 - nuInf_)
       *pow
        (
            scalar(1)
          + pow
            (
                tauStar_.value() > 0
              ? nu0*strainRate/tauStar_
              : k_*strainRate,
                a_
            ),
            (n_ - 1.0)/a_
        );
}
 
 
// ************************************************************************* //