fractal.H

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Class
    Foam::diameterModels::shapeModels::fractal
 
Description
    Class for modelling the shape of particle aggregates using the concept of
    fractal geometry. Returns a collisional diameter
 
    \f[
        d_{c_i} =
            \frac{6}{\kappa_i}
            \left(
                \frac{v_i \kappa_i^3}{36 \pi \alpha_c}
            \right)^{1/D_{f_i}}\,,
    \f]
 
    computed from a constant fractal dimension \f$D_{f_i}\f$ and a
    field-dependent surface area to volume ratio \f$\kappa_i\f$, assuming that
    the primary particles in an aggregate have the same size.
 
    The effect of sintering, i.e. the coalescence of primary particles
    resulting in a loss of surface area, is taken into account by a separate
    source term in the transport equation for \f$\kappa_i\f$.
 
Usage
    \table
        Property     | Description             | Required    | Default value
        kappa        | Initial and boundary condition value\\
                                               | yes         |
        Df           | Fractal dimension       | yes         |
        alphaC       | Scaling prefactor       | yes         |
    \endtable
 
See also
    Foam::diameterModels::shapeModel
 
SourceFiles
    fractal.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef fractal_H
#define fractal_H
 
#include "SecondaryPropertyModel.H"
#include "shapeModel.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace diameterModels
{
namespace shapeModels
{
 
class sinteringModel;
 
/*---------------------------------------------------------------------------*\
                           Class fractal Declaration
\*---------------------------------------------------------------------------*/
 
class fractal
:
    public SecondaryPropertyModel<shapeModel>
{
public:
 
    // Public Data types
 
        //- Surface growth type enumeration
        enum surfaceGrowthTypes
        {
            sgHardSphere,
            sgParkRogak,
            sgConserved
        };
 
        //- Surface growth type names
        static const NamedEnum<surfaceGrowthTypes, 3> sgTypeNames_;
 
 
private:
 
    // Private Data
 
        //- Ratio of surface area to volume
        volScalarField kappa_;
 
        //- Fractal dimension
        dimensionedScalar Df_;
 
        //- Scaling prefactor
        dimensionedScalar alphaC_;
 
        //- Collisional diameter
        volScalarField dColl_;
 
        //- Explicit source
        volScalarField Su_;
 
        //- Sintering model
        autoPtr<sinteringModel> sinteringModel_;
 
 
    // Private Member Functions
 
        //- Compute and return the collisional diameter
        tmp<volScalarField> dColl() const;
 
 
public:
 
    //- Runtime type information
    TypeName("fractal");
 
 
    // Constructors
 
        //- Construct from dictionaries and sizeGroup
        fractal
        (
            const dictionary& dict,
            const sizeGroup& group,
            const dictionary& groupDict
        );
 
        //- Disallow default bitwise copy construction
        fractal(const fractal&) = delete;
 
 
    //- Destructor
    virtual ~fractal();
 
 
    // Member Functions
 
        // Access
 
            //- Return reference to secondary property field
            virtual const volScalarField& fld() const;
 
            //- Access to secondary property source
            virtual volScalarField& src();
 
            //- Return representative surface area of the sizeGroup
            virtual const tmp<volScalarField> a() const;
 
            //- Return representative diameter of the sizeGroup
            virtual const tmp<volScalarField> d() const
            {
                return dColl_;
            }
 
        // Edit
 
            //- Correct the collisional diameter
            virtual void correct();
 
            //- Add drift contribution to secondary property source
            virtual void addDrift
            (
                const volScalarField& Su,
                const sizeGroup& fu,
                const driftModel& model
            );
 
 
    // Member Operators
 
        //- Disallow default bitwise assignment
        void operator=(const fractal&) = delete;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace shapeModels
} // End namespace diameterModels
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //