Casson.C

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    Copyright (C) 2020 OpenCFD Ltd
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#include "Casson.H"
#include "volFields.H"
#include "addToRunTimeSelectionTable.H"
 
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
namespace Foam
{
namespace laminarModels
{
namespace generalizedNewtonianViscosityModels
{
    defineTypeNameAndDebug(Casson, 0);
    addToRunTimeSelectionTable
    (
        generalizedNewtonianViscosityModel,
        Casson,
        dictionary
    );
}
}
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
Foam::laminarModels::generalizedNewtonianViscosityModels::Casson::Casson
(
    const dictionary& viscosityProperties
)
:
    generalizedNewtonianViscosityModel(viscosityProperties),
    m_("m", dimViscosity, viscosityProperties),
    tau0_("tau0", dimViscosity/dimTime, viscosityProperties),
    nuMin_("nuMin", dimViscosity, viscosityProperties),
    nuMax_("nuMax", dimViscosity, viscosityProperties)
{}
 
 
// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
bool Foam::laminarModels::generalizedNewtonianViscosityModels::Casson::read
(
    const dictionary& viscosityProperties
)
{
    generalizedNewtonianViscosityModel::read(viscosityProperties);
 
    const dictionary& coeffs =
        viscosityProperties.optionalSubDict(typeName + "Coeffs");
 
    coeffs.readEntry("m", m_);
    coeffs.readEntry("tau0", tau0_);
    coeffs.readEntry("nuMin_", nuMin_);
    coeffs.readEntry("nuMax_", nuMax_);
 
    return true;
}
 
 
Foam::tmp<Foam::volScalarField>
Foam::laminarModels::generalizedNewtonianViscosityModels::Casson::
nu
(
    const volScalarField& nu0,
    const volScalarField& strainRate
) const
{
    return max
    (
        nuMin_,
        min
        (
            nuMax_,
            sqr
            (
                sqrt
                (
                    tau0_
                   /max
                    (
                        strainRate,
                        dimensionedScalar("SMALL", dimless/dimTime, VSMALL)
                    )
                ) + sqrt(m_)
            )
        )
    );
}
 
 
// ************************************************************************* //