/*---------------------------------------------------------------------------*\
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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::particles

Description
    This functionObject tracks a particle cloud in the specified velocity field
    of an incompressible flow (laminar, RANS or LES).

    It may be used in conjunction with any transient single-phase incompressible
    flow solvers or solver modules such as incompressibleFluid and tracks the
    particles or parcels without affecting the flow-field.

    The cloud requires the density of the fluid which is looked-up from
    constant/phaseProperties dictionary and the acceleration due to gravity
    which is read from the constant/g file if present or defaults to zero.

    The cloud properties are read from the constant/\<cloudName\>Properties
    dictionary in the usual manner.

    Example of function object specification:
    \verbatim
        particles
        {
            libs        ("liblagrangianFunctionObjects.so");
            type        particles;
        }
    \endverbatim

Usage
    \table
        Property | Description                     | Required   | Default value
        type     | Type name: particles            | yes        |
        U        | Name of the velocity field      | no         | U
        cloud    | Name of the cloud               | no         | cloud
    \endtable

See also
    Foam::functionObjects::fvMeshFunctionObject

SourceFiles
    particles.C

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

#ifndef particles_functionObject_H
#define particles_functionObject_H

#include "fvMeshFunctionObject.H"
#include "parcelCloud.H"
#include "volFieldsFwd.H"
#include "uniformDimensionedFields.H"

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

namespace Foam
{

class viscosityModel;

namespace functionObjects
{

/*---------------------------------------------------------------------------*\
                          Class particles Declaration
\*---------------------------------------------------------------------------*/

class particles
:
    public fvMeshFunctionObject
{
    // Private member data

        //- Optional acceleration due to gravity
        uniformDimensionedVectorField g_;

        //- Reference to the carrier fluid viscosity model
        const viscosityModel& viscosity_;

        //- Uniform density value
        dimensionedScalar rhoValue_;

        //- Density field needed to construct the cloud
        volScalarField rho_;

        //- Dynamic viscosity field needed to construct the cloud
        volScalarField mu_;

        //- Reference to the velocity field
        const volVectorField& U_;

        //- Name of the cloud
        word cloudName_;

        //- The cloud
        autoPtr<parcelCloud> cloudPtr_;


public:

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


    // Constructors

        //- Construct for given objectRegistry and dictionary.
        //  Allow the possibility to load fields from files
        particles
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict
        );

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


    //- Destructor
    virtual ~particles();


    // Member Functions

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

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

        //- Track the cloud
        virtual bool execute();

        //- Write the cloud
        virtual bool write();


    // Member Operators

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


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

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

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

#endif

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