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    Copyright (C) 2019 OpenCFD Ltd.
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License
    This file is part of OpenFOAM.

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    the Free Software Foundation, either version 3 of the License, or
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Class
    Foam::phaseChangeTwoPhaseMixtures::Kunz

Description
    Kunz cavitation model slightly modified so that the condensation term
    is switched off when the pressure is less than the saturation vapour
    pressure.  This change allows the condensation term to be formulated as
    a coefficient multiplying (p - p_sat) so that it can be included as an
    implicit term in the pressure equation.

    Reference:
    \verbatim
        Kunz, R.F., Boger, D.A., Stinebring, D.R., Chyczewski, Lindau. J.W.,
        Gibeling, H.J., Venkateswaran, S., Govindan, T.R.,
        "A Preconditioned Implicit Method for Two-Phase Flows with Application
         to Cavitation Prediction,"
        Computers and Fluids,
        29(8):849-875, 2000.
    \endverbatim

SourceFiles
    Kunz.C

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

#ifndef Kunz_H
#define Kunz_H

#include "phaseChangeTwoPhaseMixture.H"

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

namespace Foam
{
namespace phaseChangeTwoPhaseMixtures
{

/*--------------------------------------------------------------------*\
                              Class Kunz
\*--------------------------------------------------------------------*/

class Kunz
:
    public phaseChangeTwoPhaseMixture
{
    // Private data

        dimensionedScalar UInf_;
        dimensionedScalar tInf_;
        dimensionedScalar Cc_;
        dimensionedScalar Cv_;

        dimensionedScalar p0_;

        dimensionedScalar mcCoeff_;
        dimensionedScalar mvCoeff_;


public:

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


    // Constructors

        //- Construct from components
        Kunz
        (
            const volVectorField& U,
            const surfaceScalarField& phi
        );


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


    // Member Functions

        //- Return the mass condensation and vaporisation rates as a
        //  coefficient to multiply (1 - alphal) for the condensation rate
        //  and a coefficient to multiply  alphal for the vaporisation rate
        virtual Pair<tmp<volScalarField>> mDotAlphal() const;

        //- Return the mass condensation and vaporisation rates as coefficients
        //  to multiply (p - pSat)
        virtual Pair<tmp<volScalarField>> mDotP() const;

        //- Correct the Kunz phaseChange model
        virtual void correct();

        //- Read the transportProperties dictionary and update
        virtual bool read();
};


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

} // End namespace phaseChangeTwoPhaseMixtures
} // End namespace Foam

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

#endif

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