reitzDiwakar.C

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#include <OpenFOAM/error.H>

#include "reitzDiwakar.H"
#include <OpenFOAM/addToRunTimeSelectionTable.H>
#include <reactionThermophysicalModels/basicMultiComponentMixture.H>

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

defineTypeNameAndDebug(reitzDiwakar, 0);

addToRunTimeSelectionTable
(
    breakupModel,
    reitzDiwakar,
    dictionary
);

// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

// Construct from components
reitzDiwakar::reitzDiwakar
(
    const dictionary& dict,
    spray& sm
)
:
    breakupModel(dict, sm),
    coeffsDict_(dict.subDict(typeName + "Coeffs")),
    Cbag_(readScalar(coeffsDict_.lookup("Cbag"))),
    Cb_(readScalar(coeffsDict_.lookup("Cb"))),
    Cstrip_(readScalar(coeffsDict_.lookup("Cstrip"))),
    Cs_(readScalar(coeffsDict_.lookup("Cs")))
{}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

reitzDiwakar::~reitzDiwakar()
{}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

void reitzDiwakar::breakupParcel
(
    parcel& p,
    const scalar deltaT,
    const vector& vel,
    const liquidMixture& fuels
) const
{
    /*
        These are the default values for this model...
        static const scalar Cbag   = 6.0;
        static const scalar Cb     = 0.785;
        static const scalar Cstrip = 0.5;
        static const scalar Cs     = 10.0;
    */

    const PtrList<volScalarField>& Y = spray_.composition().Y();

    label Ns = Y.size();
    label cellI = p.cell();
    scalar pressure = spray_.p()[cellI];
    scalar temperature = spray_.T()[cellI];
    scalar Taverage = p.T() + (temperature - p.T())/3.0;

    scalar muAverage = 0.0;
    scalar Winv = 0.0;
    for(label i=0; i<Ns; i++)
    {
        Winv += Y[i][cellI]/spray_.gasProperties()[i].W();
        muAverage += Y[i][cellI]*spray_.gasProperties()[i].mu(Taverage);
    }
    scalar R = specie::RR*Winv;

    // ideal gas law to evaluate density
    scalar rhoAverage = pressure/R/Taverage;
    scalar nuAverage = muAverage/rhoAverage;
    scalar sigma = fuels.sigma(pressure, p.T(), p.X());

    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
    //     The We and Re numbers are to be evaluated using the 1/3 rule.
    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

    scalar WeberNumber = p.We(vel, rhoAverage, sigma);
    scalar ReynoldsNumber = p.Re(vel, nuAverage);

    scalar sqRey = sqrt(ReynoldsNumber);

    if (WeberNumber > Cbag_)
    {
        if (WeberNumber > Cstrip_*sqRey)
        {
            scalar dStrip =
                pow(2.0*Cstrip_*sigma, 2.0)/
                (
                    rhoAverage
                  * pow(mag(p.Urel(vel)), 3.0)
                  * muAverage
                );

            scalar tauStrip =
                Cs_ * p.d()
              * sqrt
                (
                    fuels.rho(pressure, p.T(), p.X())
                    / rhoAverage
                )
              / mag(p.Urel(vel));

            scalar fraction = deltaT/tauStrip;

            // new droplet diameter, implicit calculation
            p.d() = (fraction*dStrip + p.d())/(1.0 + fraction);
        }
        else
        {
            scalar dBag =
                2.0 * Cbag_ * sigma
              / (
                  rhoAverage
                * pow(mag(p.Urel(vel)), 2.0)
                );

            scalar tauBag =
                Cb_ * p.d()
                * sqrt
                  (
                      fuels.rho(pressure, p.T(), p.X())
                    * p.d()
                    / sigma
                  );

            scalar fraction = deltaT/tauBag;

            // new droplet diameter, implicit calculation
            p.d() = (fraction*dBag + p.d())/(1.0 + fraction);
        }

    }

}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

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