homogeneousCondensation.C

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#include "homogeneousCondensation.H"
#include "fundamentalConstants.H"
#include "multicomponentThermo.H"
#include "physicoChemicalConstants.H"
#include "phaseSystem.H"
#include "addToRunTimeSelectionTable.H"
 
// * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
 
namespace Foam
{
namespace fv
{
    defineTypeNameAndDebug(homogeneousCondensation, 0);
    addToRunTimeSelectionTable(fvModel, homogeneousCondensation, dictionary);
}
}
 
// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
void Foam::fv::homogeneousCondensation::readCoeffs(const dictionary& dict)
{
    reReadSpecie(dict);
 
    saturationModel_.reset
    (
        saturationPressureModel::New("pSat", dict).ptr()
    );
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
Foam::fv::homogeneousCondensation::homogeneousCondensation
(
    const word& name,
    const word& modelType,
    const fvMesh& mesh,
    const dictionary& dict
)
:
    phaseChange(name, modelType, mesh, dict, readSpecie(dict, true)),
    fluid_
    (
        mesh().lookupObject<phaseSystem>(phaseSystem::propertiesName)
    ),
    d_
    (
        IOobject
        (
            name + ":d",
            mesh.time().name(),
            mesh,
            IOobject::READ_IF_PRESENT,
            IOobject::AUTO_WRITE
        ),
        mesh,
        dimensionedScalar(dimLength, 0)
    ),
    mDotByAlphaGas_
    (
        IOobject
        (
            name + ":mDotByAlpha",
            mesh.time().name(),
            mesh,
            IOobject::READ_IF_PRESENT,
            IOobject::AUTO_WRITE
        ),
        mesh,
        dimensionedScalar(dimDensity/dimTime, 0)
    ),
    saturationModel_(nullptr)
{
    readCoeffs(coeffs(dict));
}
 
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
Foam::tmp<Foam::volScalarField::Internal>
Foam::fv::homogeneousCondensation::d() const
{
    return d_;
}
 
 
Foam::tmp<Foam::volScalarField::Internal>
Foam::fv::homogeneousCondensation::nDot() const
{
    const volScalarField::Internal& alphaGas =
        mesh().lookupObject<volScalarField::Internal>(alphaNames().first());
 
    const ThermoRefPair<multicomponentThermo> multicomponentThermos =
        this->multicomponentThermos(true, false);
 
    const multicomponentThermo& thermoGas = multicomponentThermos.first();
 
    const volScalarField& p = this->p();
    const volScalarField& T = thermoGas.T();
 
    const volScalarField::Internal rhoLiquid
    (
        multicomponentThermos.valid().second()
      ? vfToVif(multicomponentThermos.second().rhoi(specieis().second(), p, T))
      : vfToVif(thermos().second().rho())
    );
 
    const volScalarField::Internal v(constant::mathematical::pi/6*pow3(d_));
 
    return alphaGas*mDotByAlphaGas_/(rhoLiquid*v);
}
 
 
Foam::tmp<Foam::volScalarField::Internal>
Foam::fv::homogeneousCondensation::mDot() const
{
    const volScalarField::Internal& alphaGas =
        mesh().lookupObject<volScalarField::Internal>(alphaNames().first());
 
    return alphaGas*mDotByAlphaGas_;
}
 
 
Foam::tmp<Foam::volScalarField::Internal>
Foam::fv::homogeneousCondensation::tau() const
{
    static const dimensionedScalar mDotRootVSmall
    (
        dimDensity/dimTime,
        rootVSmall
    );
 
    const ThermoRefPair<multicomponentThermo> multicomponentThermos =
        this->multicomponentThermos(true, false);
 
    const multicomponentThermo& thermoGas = multicomponentThermos.first();
 
    // Phase molecular masses and densities
    const volScalarField::Internal WGas(vfToVif(thermoGas.W()));
    const volScalarField::Internal rhoGas(vfToVif(thermoGas.rho()));
 
    // Mole fraction of nucleating specie
    const volScalarField::Internal Xi
    (
        thermoGas.Y()[specieis().first()]*WGas/thermoGas.Wi(specieis().first())
    );
 
    return Xi*rhoGas/max(mDotByAlphaGas_, mDotRootVSmall);
}
 
 
void Foam::fv::homogeneousCondensation::correct()
{
    #define DebugField(field)                                                  \
        DebugInfo                                                              \
            << name() << ": "                                                  \
            << #field << ' ' << field.dimensions() << " min/avg/max = "        \
            << gMin(field) << '/' << gAverage(field) << '/' << gMax(field)     \
            << nl;
 
    using constant::mathematical::pi;
    using constant::physicoChemical::NNA;
    using constant::physicoChemical::k;
 
    const ThermoRefPair<multicomponentThermo> multicomponentThermos =
        this->multicomponentThermos(true, false);
 
    const multicomponentThermo& thermoGas = multicomponentThermos.first();
 
    const volScalarField& p = this->p();
    const volScalarField& T = thermoGas.T();
    DebugField(p);
    DebugField(T);
 
    // Phase molecular masses and densities
    const volScalarField::Internal WGas(vfToVif(thermoGas.W()));
    const volScalarField::Internal rhoGas(vfToVif(thermoGas.rho()));
    const volScalarField::Internal WLiquid
    (
        multicomponentThermos.valid().second()
      ? volScalarField::Internal::New
        (
            "W",
            mesh(),
            multicomponentThermos.second().Wi(specieis().second())
        )
      : vfToVif(thermos().second().W())
    );
    const volScalarField::Internal rhoLiquid
    (
        multicomponentThermos.valid().second()
      ? vfToVif(multicomponentThermos.second().rhoi(specieis().second(), p, T))
      : vfToVif(thermos().second().rho())
    );
    DebugField(WGas);
    DebugField(rhoGas);
    DebugField(WLiquid);
    DebugField(rhoLiquid);
 
    // Surface tension
    const volScalarField::Internal sigma
    (
        fluid_.sigma
        (
            phaseInterface
            (
                fluid_.phases()[phaseNames().first()],
                fluid_.phases()[phaseNames().second()]
            )
        )
    );
    DebugField(sigma);
 
    // Mole fraction of nucleating specie
    const volScalarField::Internal Xi
    (
        thermoGas.Y()[specieis().first()]*WGas/thermoGas.Wi(specieis().first())
    );
 
    // Saturation pressure and concentration
    const volScalarField::Internal pSat(saturationModel_->pSat(T()));
    const volScalarField::Internal cSat(pSat/p()*rhoGas/WGas);
    DebugField(pSat);
    DebugField(cSat);
 
    // Supersaturation of the nucleating specie
    const volScalarField::Internal S(Xi*p()/pSat);
    DebugField(S);
 
    // Mass, volume and diameter of one molecule in the condensed phase
    const volScalarField::Internal mMolc(WLiquid/NNA);
    const volScalarField::Internal vMolc(mMolc/rhoLiquid);
    const volScalarField::Internal dMolc(cbrt(6/pi*vMolc));
    DebugField(mMolc);
    DebugField(vMolc);
    DebugField(dMolc);
 
    // Diameter of nuclei
    d_ = 4*sigma*vMolc/(k*T()*log(max(S, 1 + small)));
    DebugField(d_);
 
    // ?
    const volScalarField::Internal deltaPhiStar(pi/3*sigma*sqr(d_));
    DebugField(deltaPhiStar);
 
    // Ratio of nucleus volume to molecular volume
    const volScalarField::Internal iStar(pi/6*pow3(d_)/vMolc);
    DebugField(iStar);
 
    // ?
    const volScalarField::Internal betaIStar1
    (
        sqrt(6*k*T()/mMolc)*sqrt((iStar + 1)/iStar)*sqr(d_/2 + dMolc/2)
    );
    DebugField(betaIStar1);
 
    // Number-based nucleation rate; i.e., number of nuclei created per second
    // per unit volume
    const volScalarField::Internal J
    (
        betaIStar1*sqr(cSat*NNA)*exp(-deltaPhiStar/(k*T()))
       *sqrt(sigma/(k*T()))
       *2*mMolc/(pi*sqr(d_)*rhoLiquid)
    );
    DebugField(J);
 
    // Mass transfer rate
    mDotByAlphaGas_ = J*iStar*mMolc;
    DebugField(mDotByAlphaGas_);
 
    #undef DebugField
}
 
 
void Foam::fv::homogeneousCondensation::addSup
(
    const volScalarField& alpha,
    const volScalarField& rho,
    fvMatrix<scalar>& eqn
) const
{
    const label i = index(alphaNames(), eqn.psi().name());
 
    // !!! Note at present multiphaseEuler cannot linearise w.r.t alphaA in the
    // continuity equation for alphaB. So we can only create a linearised
    // source for this model in the gas volume-fraction equation.
 
    if (i == 0)
    {
        eqn -= fvm::Sp(mDotByAlphaGas_, eqn.psi());
    }
    else
    {
        massTransfer::addSup(alpha, rho, eqn);
    }
}
 
 
bool Foam::fv::homogeneousCondensation::read(const dictionary& dict)
{
    if (phaseChange::read(dict))
    {
        readCoeffs(coeffs(dict));
        return true;
    }
    else
    {
        return false;
    }
}
 
 
// ************************************************************************* //