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    Copyright (C) 2018-2020 OpenFOAM Foundation
    Copyright (C) 2020 OpenCFD Ltd.
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License
    This file is part of OpenFOAM.

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    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

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#include "powerLaw.H"
#include "volgpuFields.H"
#include "addToRunTimeSelectionTable.H"

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

namespace Foam
{
namespace laminarModels
{
namespace generalizedNewtonianViscosityModels
{
    defineTypeNameAndDebug(powerLaw, 0);

    addToRunTimeSelectionTable
    (
        generalizedNewtonianViscosityModel,
        powerLaw,
        dictionary
    );
}
}
}


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

Foam::laminarModels::generalizedNewtonianViscosityModels::powerLaw::powerLaw
(
    const dictionary& viscosityProperties
)
:
    generalizedNewtonianViscosityModel(viscosityProperties),
    powerLawCoeffs_(viscosityProperties.optionalSubDict(typeName + "Coeffs")),
    n_("n", dimless, powerLawCoeffs_),
    nuMin_("nuMin", dimViscosity, powerLawCoeffs_),
    nuMax_("nuMax", dimViscosity, powerLawCoeffs_)
{}


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

bool Foam::laminarModels::generalizedNewtonianViscosityModels::powerLaw::read
(
    const dictionary& viscosityProperties
)
{
    generalizedNewtonianViscosityModel::read(viscosityProperties);

    powerLawCoeffs_ = viscosityProperties.optionalSubDict(typeName + "Coeffs");

    powerLawCoeffs_.readEntry("n", n_);
    powerLawCoeffs_.readEntry("nuMin", nuMin_);
    powerLawCoeffs_.readEntry("nuMax", nuMax_);

    return true;
}


Foam::tmp<Foam::volScalargpuField>
Foam::laminarModels::generalizedNewtonianViscosityModels::powerLaw::
nu
(
    const volScalargpuField& nu0,
    const volScalargpuField& strainRate
) const
{
    return max
    (
        nuMin_,
        min
        (
            nuMax_,
            nu0*pow
            (
                max
                (
                    dimensionedScalar("one", dimTime, 1)*strainRate,
                    dimensionedScalar("small", dimless, SMALL)
                ),
                n_.value() - scalar(1)
            )
        )
    );
}


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