NonSphereDragForce.H

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/*---------------------------------------------------------------------------*\
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-------------------------------------------------------------------------------
    Copyright (C) 2011-2017 OpenFOAM Foundation
-------------------------------------------------------------------------------
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
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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::NonSphereDragForce
 
Group
    grpLagrangianIntermediateForceSubModels
 
Description
    Drag model for non-spherical particles.
 
    Takes the form of
 
        24.0/Re*(1.0 + a_*pow(Re, b_)) + Re*c_/(Re + d_);
 
    Where a(phi), b(phi), c(phi) and d(phi) are model coefficients, with phi
    defined as:
 
              area of sphere with same volume as particle
        phi = -------------------------------------------
                       actual particle area
 
    Equation used is Eqn (11) of reference below - good to within 2 to 4 % of
    RMS values from experiment.
 
    H and L also give a simplified model with greater error compared to
    results from experiment - Eqn 12 - but since phi is presumed
    constant, it offers little benefit.
 
    Reference:
    \verbatim
        "Drag coefficient and terminal velocity of spherical and nonspherical
        particles"
        A. Haider and O. Levenspiel,
        Powder Technology
        Volume 58, Issue 1, May 1989, Pages 63-70
    \endverbatim
 
 
\*---------------------------------------------------------------------------*/
 
#ifndef NonSphereDragForce_H
#define NonSphereDragForce_H
 
#include "ParticleForce.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
/*---------------------------------------------------------------------------*\
                    Class NonSphereDragForce Declaration
\*---------------------------------------------------------------------------*/
 
template<class CloudType>
class NonSphereDragForce
:
    public ParticleForce<CloudType>
{
protected:
 
    // Protected Data
 
        //- Ratio of surface of sphere having same volume as particle to
        //  actual surface area of particle (0 < phi <= 1)
        scalar phi_;
 
 
        // Model coefficients
 
            scalar a_;
 
            scalar b_;
 
            scalar c_;
 
            scalar d_;
 
 
    // Private Member Functions
 
        //- Drag coefficient multiplied by Reynolds number
        scalar CdRe(const scalar Re) const;
 
 
public:
 
    //- Runtime type information
    TypeName("nonSphereDrag");
 
 
    // Constructors
 
        //- Construct from mesh
        NonSphereDragForce
        (
            CloudType& owner,
            const fvMesh& mesh,
            const dictionary& dict
        );
 
        //- Construct copy
        NonSphereDragForce(const NonSphereDragForce<CloudType>& df);
 
        //- Construct and return a clone
        virtual autoPtr<ParticleForce<CloudType>> clone() const
        {
            return autoPtr<ParticleForce<CloudType>>
            (
                new NonSphereDragForce<CloudType>(*this)
            );
        }
 
 
    //- Destructor
    virtual ~NonSphereDragForce();
 
 
    // Member Functions
 
        // Evaluation
 
            //- Calculate the non-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 "NonSphereDragForce.C"
#endif
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //