RanzMarshall.H

Go to the documentation of this file.

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | www.openfoam.com
     \\/     M anipulation  |
-------------------------------------------------------------------------------
    Copyright (C) 2011-2016 OpenFOAM Foundation
    Copyright (C) 2021 OpenCFD Ltd.
-------------------------------------------------------------------------------
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::RanzMarshall
 
Group
    grpLagrangianIntermediateHeatTransferSubModels
 
Description
    Nusselt-number model using the empirical Ranz-Marshall correlation
    to be used in modelling of the fluid-particle heat transfer coefficient:
 
    \f[
        \mathrm{Nu} = a + b \, \mathrm{Re}_p^{m} \, \mathrm{Pr}^{n}
    \f]
    with
 
    \f[
        \mathrm{Re}_p =
            \frac{\rho_c \, | \mathbf{u}_\mathrm{rel} | \, d_p}{\mu_c}
    \f]
 
    \f[
        \mathrm{Pr} = \frac{ C_p \, \mu_c }{ \kappa_c }
    \f]
    where
 
    \vartable
        \mathrm{Nu}    | Nusselt number
        \mathrm{Re}_p  | Particle Reynolds number
        \mathrm{Pr}    | Prandtl number
        d_p            | Particle diameter
        \rho_c         | Density of carrier in the film surrounding particle
        \mu_c    | Dynamic viscosity of carrier in the film surrounding particle
        \mathbf{u}_\mathrm{rel} | Relative velocity between particle and carrier
        a              | Correlation coefficient
        b              | Correlation coefficient
        m              | Correlation exponent of particle Reynolds number
        n              | Correlation exponent of Prandtl number
        C_p            | Specific heat capacity
        \kappa_c       | Thermal conductivity of carrier in the film
    \endvartable
 
    Reference:
    \verbatim
        Standard model:
            Ranz, W. E., & Marshall, W. R. (1952).
            Evaporation from drops - part 1.
            Chem. Eng. Prog, 48, 22, pp. 141-146.
 
            Ranz, W. E., & Marshall, W. R. (1952).
            Evaporation from drops - part 2.
            Chem. Eng. Prog, 48, 4, pp. 173-180.
 
        Expressions (tag:AOB), p. 18:
            Amsden, A. A., O'Rourke, P. J., & Butler, T. D. (1989).
            KIVA-II: A computer program for chemically
            reactive flows with sprays (No. LA-11560-MS).
            Los Alamos National Lab.(LANL), Los Alamos, NM (United States).
            DOI:10.2172/6228444
    \endverbatim
 
Usage
    Minimal example by using \c constant/<CloudProperties>:
    \verbatim
    subModels
    {
        // Mandatory entries
        heatTransferModel    RanzMarshall;
 
        // Optional entries
        RanzMarshallCoeffs
        {
            a    2.0;
            b    0.6;
            m    0.5;
            n    0.66666;
        }
    }
    \endverbatim
 
    where the entries mean:
    \table
      Property           | Description              | Type | Reqd | Deflt
      heatTransferModel  | Type name: RanzMarshall  | word | yes  | -
      a                  | Correlation coefficient  | scalar | no | 2.0
      b                  | Correlation coefficient  | scalar | no | 0.6
      m  | Correlation exponent of particle Reynolds number | scalar | no | 0.5
      n  | Correlation exponent of Prandtl number   | scalar | no | 1.0/3.0
    \endtable
 
SourceFiles
    RanzMarshall.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef RanzMarshall_H
#define RanzMarshall_H
 
#include "HeatTransferModel.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                         Class RanzMarshall Declaration
\*---------------------------------------------------------------------------*/
 
template<class CloudType>
class RanzMarshall
:
    public HeatTransferModel<CloudType>
{
    // Private Data
 
        //- Correlation coefficient
        const scalar a_;
 
        //- Correlation coefficient
        const scalar b_;
 
        //- Correlation exponent of particle Reynolds number
        const scalar m_;
 
        //- Correlation exponent of Prandtl number
        const scalar n_;
 
 
public:
 
    //- Runtime type information
    TypeName("RanzMarshall");
 
 
    // Generated Methods
 
        //- No copy assignment
        void operator=(const RanzMarshall&) = delete;
 
 
    // Constructors
 
        //- Construct from dictionary
        RanzMarshall(const dictionary& dict, CloudType& cloud);
 
        //- Copy construct
        RanzMarshall(const RanzMarshall<CloudType>& im);
 
        //- Construct and return a clone
        virtual autoPtr<HeatTransferModel<CloudType>> clone() const
        {
            return autoPtr<HeatTransferModel<CloudType>>
            (
                new RanzMarshall<CloudType>(*this)
            );
        }
 
 
    //- Destructor
    virtual ~RanzMarshall() = default;
 
 
    // Member Functions
 
        // Evaluation
 
            //- Return Nusselt number
            virtual scalar Nu
            (
                const scalar Re,
                const scalar Pr
            ) const;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#ifdef NoRepository
    #include "RanzMarshall.C"
#endif
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //