/*---------------------------------------------------------------------------*\
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    Copyright (C) 2016 OpenFOAM Foundation
    Copyright (C) 2017-2019 OpenCFD Ltd
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License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
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Class
    Foam::viscosityModels::strainRateFunction

Description
    Run-time selected strain-rate function non-Newtonian viscosity model.

    Example linear function of strain-rate:
    \verbatim
        transportModel  strainRateFunction;

        strainRateFunctionCoeffs
        {
            function polynomial ((0 0.1) (1 1.3));
        }
    \endverbatim

See also
    Foam::viscosityModel
    Foam::Function1

SourceFiles
    strainRateFunction.C

\*---------------------------------------------------------------------------*/

#ifndef strainRateFunction_H
#define strainRateFunction_H

#include "viscosityModel.H"
#include "volFields.H"
#include "Function1.H"

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

namespace Foam
{
namespace viscosityModels
{

/*---------------------------------------------------------------------------*\
                           Class strainRateFunction Declaration
\*---------------------------------------------------------------------------*/

class strainRateFunction
:
    public viscosityModel
{
    // Private data

        //- Coefficients dictionary
        dictionary strainRateFunctionCoeffs_;

        //- Strain-rate function
        autoPtr<Function1<scalar>> strainRateFunction_;


protected:

    // Protected data

        volScalarField nu_;


public:

    //- Runtime type information
    TypeName("strainRateFunction");


    // Constructors

        //- Construct from components
        strainRateFunction
        (
            const word& name,
            const dictionary& viscosityProperties,
            const volVectorField& U,
            const surfaceScalarField& phi
        );


    //- Destructor
    virtual ~strainRateFunction() = default;


    // Member Functions

        //- Return the laminar viscosity
        virtual tmp<volScalarField> nu() const;

        //- Return the laminar viscosity for patch
        virtual tmp<scalarField> nu(const label patchi) const;

        //- Correct the laminar viscosity
        virtual void correct();

        //- Read transportProperties dictionary
        virtual bool read(const dictionary& viscosityProperties);
};


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

} // End namespace viscosityModels
} // End namespace Foam

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

#endif

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