COxidationKineticDiffusionLimitedRate.C

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#include "COxidationKineticDiffusionLimitedRate.H"
#include <OpenFOAM/mathematicalConstants.H>

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

template<class CloudType>
Foam::COxidationKineticDiffusionLimitedRate<CloudType>::
COxidationKineticDiffusionLimitedRate
(
    const dictionary& dict,
    CloudType& owner
)
:
    SurfaceReactionModel<CloudType>
    (
        dict,
        owner,
        typeName
    ),
    Sb_(dimensionedScalar(this->coeffDict().lookup("Sb")).value()),
    C1_(dimensionedScalar(this->coeffDict().lookup("C1")).value()),
    C2_(dimensionedScalar(this->coeffDict().lookup("C2")).value()),
    E_(dimensionedScalar(this->coeffDict().lookup("E")).value()),
    CsLocalId_(-1),
    O2GlobalId_(owner.composition().globalCarrierId("O2")),
    CO2GlobalId_(owner.composition().globalCarrierId("CO2")),
    WC_(0.0),
    WO2_(0.0),
    HcCO2_(0.0)
{
    // Determine Cs ids
    label idSolid = owner.composition().idSolid();
    CsLocalId_ = owner.composition().localId(idSolid, "C");

    // Set local copies of thermo properties
    WO2_ = owner.mcCarrierThermo().speciesData()[O2GlobalId_].W();
    scalar WCO2 = owner.mcCarrierThermo().speciesData()[CO2GlobalId_].W();
    WC_ = WCO2 - WO2_;
    HcCO2_ = owner.mcCarrierThermo().speciesData()[CO2GlobalId_].Hc();

    if (Sb_ < 0)
    {
        FatalErrorIn
        (
            "COxidationKineticDiffusionLimitedRate"
            "("
                "const dictionary&, "
                "CloudType&"
            ")"
        )   << "Stoichiometry of reaction, Sb, must be greater than zero" << nl
            << exit(FatalError);
    }
}


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

template<class CloudType>
Foam::COxidationKineticDiffusionLimitedRate<CloudType>::
~COxidationKineticDiffusionLimitedRate()
{}


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

template<class CloudType>
bool Foam::COxidationKineticDiffusionLimitedRate<CloudType>::active() const
{
    return true;
}


template<class CloudType>
Foam::scalar Foam::COxidationKineticDiffusionLimitedRate<CloudType>::calculate
(
    const scalar dt,
    const label cellI,
    const scalar d,
    const scalar T,
    const scalar Tc,
    const scalar pc,
    const scalar rhoc,
    const scalar mass,
    const scalarField& YGas,
    const scalarField& YLiquid,
    const scalarField& YSolid,
    const scalarField& YMixture,
    const scalar N,
    scalarField& dMassGas,
    scalarField& dMassLiquid,
    scalarField& dMassSolid,
    scalarField& dMassSRCarrier
) const
{
    // Fraction of remaining combustible material
    const label idSolid = CloudType::parcelType::SLD;
    const scalar fComb = YMixture[idSolid]*YSolid[CsLocalId_];

    // Surface combustion active combustible fraction is consumed
    if (fComb < SMALL)
    {
        return 0.0;
    }

    // Local mass fraction of O2 in the carrier phase
    const scalar YO2 = this->owner().mcCarrierThermo().Y(O2GlobalId_)[cellI];

    // Diffusion rate coefficient
    const scalar D0 = C1_/d*pow(0.5*(T + Tc), 0.75);

    // Kinetic rate
    const scalar Rk = C2_*exp(-E_/(specie::RR*Tc));

    // Particle surface area
    const scalar Ap = mathematicalConstant::pi*sqr(d);

    // Change in C mass [kg]
    scalar dmC = Ap*rhoc*specie::RR*Tc*YO2/WO2_*D0*Rk/(D0 + Rk)*dt;

    // Limit mass transfer by availability of C
    dmC = min(mass*fComb, dmC);

    // Change in O2 mass [kg]
    const scalar dmO2 = dmC/WC_*Sb_*WO2_;

    // Mass of newly created CO2 [kg]
    const scalar dmCO2 = dmC + dmO2;

    // Update local particle C mass
    dMassSolid[CsLocalId_] += dmC;

    // Update carrier O2 and CO2 mass
    dMassSRCarrier[O2GlobalId_] -= dmO2;
    dMassSRCarrier[CO2GlobalId_] += dmCO2;

    // Heat of reaction [J]
    return -HcCO2_*dmCO2;
}


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