BrownianMotionForce.H

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/*---------------------------------------------------------------------------*\
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    Copyright (C) 2011-2017 OpenFOAM Foundation
    Copyright (C) 2021 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.
 
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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
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::BrownianMotionForce
 
Description
    Calculates particle Brownian motion force.
 
    Reference:
    \verbatim
        Li, A., & Ahmadi, G. (1992).
        Dispersion and deposition of spherical particles from point sources
        in a turbulent channel flow.
        Aerosol science and technology,
        16(4), 209-226.
    \endverbatim
 
    Entries
    \table
        Property | Description                            | Type | Reqd | Deflt
        lambda   | Molecular free path length             | scalar | yes  | -
        turbulence | Use turbulence                       | bool | yes | -
        spherical | Spherical instead of cubic distribution | bool | no  | true
    \endtable
 
Note
    The treatment changed from cubic to spherical around v1606.
    Reinstate support for cubic via spherical (true/false) switch after v2306.
 
SourceFiles
    BrownianMotionForce.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef Foam_BrownianMotionForce_H
#define Foam_BrownianMotionForce_H
 
#include "ParticleForce.H"
#include "Random.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                    Class BrownianMotionForce Declaration
\*---------------------------------------------------------------------------*/
 
template<class CloudType>
class BrownianMotionForce
:
    public ParticleForce<CloudType>
{
    // Private Data
 
        //- Reference to the cloud random number generator
        Random& rndGen_;
 
        //- Molecular free path length [m]
        const scalar lambda_;
 
        //- Pointer to the turbulence kinetic energy field
        const volScalarField* kPtr_;
 
        //- Turbulence flag
        bool turbulence_;
 
        //- Local ownership of the turbulence k field
        bool ownK_;
 
        //- Spherical vs cubic (transitional)
        bool useSpherical_;
 
 
    // Private Member Functions
 
        //- Return the k field from the turbulence model
        tmp<volScalarField> kModel() const;
 
 
public:
 
    //- Runtime type information
    TypeName("BrownianMotion");
 
 
    // Constructors
 
        //- Construct from mesh
        BrownianMotionForce
        (
            CloudType& owner,
            const fvMesh& mesh,
            const dictionary& dict
        );
 
        //- Construct copy
        BrownianMotionForce(const BrownianMotionForce& bmf);
 
        //- Construct and return a clone
        virtual autoPtr<ParticleForce<CloudType>> clone() const
        {
            return autoPtr<ParticleForce<CloudType>>
            (
                new BrownianMotionForce<CloudType>(*this)
            );
        }
 
 
    //- Destructor
    virtual ~BrownianMotionForce();
 
 
    // Member Functions
 
    // Access
 
        //- The molecular free path length [m]
        scalar lambda() const noexcept { return lambda_; }
 
        //- The turbulence flag
        bool turbulence() const noexcept { return turbulence_; }
 
 
        // Evaluation
 
            //- Cache fields
            virtual void cacheFields(const bool store);
 
            //- Calculate the coupled force
            virtual forceSuSp calcCoupled
            (
                const typename CloudType::parcelType& p,
                const typename CloudType::parcelType::trackingData& td,
                const scalar dt,
                const scalar mass,
                const scalar Re,
                const scalar muc
            ) const;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#ifdef NoRepository
    #include "BrownianMotionForce.C"
#endif
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //