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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
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    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
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

Class
    Foam::fv::phaseLimitStabilisation

Description
    Stabilisation source for phase transport equations

    Applies an implicit source to the phase transport equation for the
    specified \c field when the phase volume fraction is below \c
    residualAlpha. The stabilisation rate is provided by the registered \c rate
    which can either be a uniformDimensionedScalarField, a volScalarField or a
    volInternalScalarField. The \c field is currently stabilised towards zero
    in the limit of the phase volume fraction approaching zero but this could
    be extended to support a specified value or a value or field looked-up from
    the database.

Usage
    Example usage:
    \verbatim
    stabilisation
    {
        type            phaseLimitStabilisation;

        field           sigma.liquid;

        rate            rLambda.liquid;

        residualAlpha   1e-3;
    }
    \endverbatim

SourceFiles
    phaseLimitStabilisation.C

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

#ifndef phaseLimitStabilisation_H
#define phaseLimitStabilisation_H

#include "fvModel.H"

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

namespace Foam
{
namespace fv
{

/*---------------------------------------------------------------------------*\
                   Class phaseLimitStabilisation Declaration
\*---------------------------------------------------------------------------*/

class phaseLimitStabilisation
:
    public fvModel
{
    // Private Data

        //- Field name
        word fieldName_;

        //- Rate field name
        word rateName_;

        //- Residual alpha value below which stabilisation is applied
        scalar residualAlpha_;


    // Private Member Functions

        //- Non-virtual read
        void readCoeffs(const dictionary& dict);

        //- Add stabilisation source terms
        template<class Type, class RhoRateFieldType>
        void addStabilisation
        (
            const volScalarField& alpha,
            const RhoRateFieldType& rhoRate,
            fvMatrix<Type>& eqn
        ) const;

        //- Add source terms to an incompressible phase equation
        template<class Type>
        void addSupType
        (
            const volScalarField& alpha,
            const VolField<Type>& field,
            fvMatrix<Type>& eqn
        ) const;

        //- Add source terms to a phase equation
        template<class Type, class RhoFieldType>
        void addSupType
        (
            const volScalarField& alpha,
            const RhoFieldType& rho,
            const VolField<Type>& field,
            fvMatrix<Type>& eqn
        ) const;


public:

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


    // Constructors

        //- Construct from components
        phaseLimitStabilisation
        (
            const word& name,
            const word& modelType,
            const fvMesh& mesh,
            const dictionary& dict
        );

        //- Disallow default bitwise copy construction
        phaseLimitStabilisation(const phaseLimitStabilisation&) = delete;


    //- Destructor
    virtual ~phaseLimitStabilisation()
    {}


    // Member Functions

        // Checks

            //- Return the list of fields for which the fvModel adds source term
            //  to the transport equation
            virtual wordList addSupFields() const;


        // Sources

            //- Add a source term to an incompressible phase equation
            FOR_ALL_FIELD_TYPES(DEFINE_FV_MODEL_ADD_RHO_FIELD_SUP)

            //- Add a source term to a phase equation
            FOR_ALL_FIELD_TYPES(DEFINE_FV_MODEL_ADD_ALPHA_RHO_FIELD_SUP)


        // Mesh changes

            //- Update for mesh motion
            virtual bool movePoints();

            //- Update topology using the given map
            virtual void topoChange(const polyTopoChangeMap&);

            //- Update from another mesh using the given map
            virtual void mapMesh(const polyMeshMap&);

            //- Redistribute or update using the given distribution map
            virtual void distribute(const polyDistributionMap&);


        //- Read dictionary
        virtual bool read(const dictionary& dict);


    // Member Operators

        //- Disallow default bitwise assignment
        void operator=(const phaseLimitStabilisation&) = delete;
};


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

} // End namespace fv
} // End namespace Foam

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

#endif

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