/*---------------------------------------------------------------------------*\
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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::functionObjects::phaseForces

Description
    This functionObject calculates and outputs the blended interfacial forces
    acting on a given phase, i.e. drag, virtual mass, lift, wall-lubrication and
    turbulent dispersion. Note that it works only in run-time processing mode
    and in combination with the multiphaseEuler solver module.

    For a simulation involving more than two phases, the accumulated force is
    calculated by looping over all interfaces involving that phase. The fields
    are stored in the database so that they can be processed further, e.g. with
    the fieldAveraging functionObject.

    Example of function object specification:
    \verbatim
    phaseForces.water
    {
        type            phaseForces;

        libs ("libmultiphaseEulerFunctionObjects.so");

        phase           water;
    }
    \endverbatim

Usage
    \table
        Property     | Description             | Required    | Default value
        type         | type name: phaseForces  | yes         |
        phase        | Name of evaluated phase | yes         |
    \endtable

See also
    Foam::BlendedInterfacialModel
    Foam::functionObjects::fvMeshFunctionObject
    Foam::functionObject

SourceFiles
    phaseForces.C

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

#ifndef functionObjects_phaseForces_H
#define functionObjects_phaseForces_H

#include "fvMeshFunctionObject.H"
#include "phaseSystem.H"

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

namespace Foam
{
namespace functionObjects
{

/*---------------------------------------------------------------------------*\
                         Class phaseForces Declaration
\*---------------------------------------------------------------------------*/

class phaseForces
:
    public fvMeshFunctionObject
{
protected:

    // Protected data

        //- Force fields
        HashPtrTable<volVectorField> forceFields_;

        //- Phase for which forces are evaluated
        const phaseModel& phase_;

        //- Constant access to phaseSystem
        const phaseSystem& fluid_;


public:

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


    // Constructors

        //- Construct from Time and dictionary
        phaseForces
        (
            const word& name,
            const Time& runTime,
            const dictionary&
        );

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


    //- Destructor
    virtual ~phaseForces();


    // Member Functions

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

        //- Return the list of fields required
        virtual wordList fields() const
        {
            return wordList::null();
        }

        //- Calculate the force fields
        virtual bool execute();

        //- Write the force fields
        virtual bool write();


    // Member Operators

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


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

} // End namespace functionObjects
} // End namespace Foam

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

#endif

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