BrownianCollisions.H

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License
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Class
    Foam::populationBalance::coalescenceModels::BrownianCollisions
 
Description
    Model describing coagulation due to Brownian motion. Utilises collisional
    diameters and the Cunningham slip correction. The slip correction
    coefficient is implemented in the following form:
 
    \f[
        C_{c_i} = 1 + \lambda [A_1 + A_2 \exp(-A_3 d_i/\lambda)]/d_i\,.
    \f]
 
    The coefficients default to the values proposed by Davis (1945). The mean
    free path is computed by
 
    \f[
        \lambda = \frac{kT}{\sqrt{2} \pi p \sigma^{2}}\,.
    \f]
 
    \vartable
        A_1       | Coefficient [-]
        A_2       | Coefficient [-]
        A_3       | Coefficient [-]
        \sigma    | Lennard-Jones parameter [m]
    \endvartable
 
    Reference:
    \verbatim
        Davies, C. N. (1945).
        Definitive equations for the fluid resistance of spheres.
        Proceedings of the Physical Society, 57(4), 259.
    \endverbatim
 
Usage
    \table
        Property    | Description                | Required    | Default value
        A1          | Coefficient A1             | no          | 2.514
        A2          | Coefficient A2             | no          | 0.8
        A3          | Coefficient A2             | no          | 0.55
        sigma       | Lennard-Jones parameter    | yes         | none
    \endtable
 
SourceFiles
    BrownianCollisions.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef BrownianCollisions_H
#define BrownianCollisions_H
 
#include "coalescenceModel.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace populationBalance
{
namespace coalescenceModels
{
 
/*---------------------------------------------------------------------------*\
                     Class BrownianCollisions Declaration
\*---------------------------------------------------------------------------*/
 
class BrownianCollisions
:
    public coalescenceModel
{
    // Private Data
 
        //- Cunningham slip correction coefficient A1
        const dimensionedScalar A1_;
 
        //- Cunningham slip correction coefficient A2
        const dimensionedScalar A2_;
 
        //- Cunningham slip correction coefficient A3
        const dimensionedScalar A3_;
 
        //- Lennard-Jones sigma parameter
        const dimensionedScalar sigma_;
 
        //- Mean free path
        volScalarField::Internal lambda_;
 
 
public:
 
    //- Runtime type information
    TypeName("BrownianCollisions");
 
    // Constructor
 
        BrownianCollisions
        (
            const populationBalanceModel& popBal,
            const dictionary& dict
        );
 
 
    //- Destructor
    virtual ~BrownianCollisions()
    {}
 
 
    // Member Functions
 
        //- Pre-compute diameter independent expressions
        virtual void precompute();
 
        //- Return the coalescence rate between two groups
        virtual tmp<volScalarField::Internal> rate
        (
            const label i,
            const label j
        ) const;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace coalescenceModels
} // End namespace populationBalance
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //