tmp<scalarField>
alphatPhaseChangeJayatillekeWallFunctionFvPatchScalarField::calcAlphat
(
const scalarField& prevAlphat
) const
{
// Lookup the fluid model
const phaseSystem& fluid =
db().lookupObject<phaseSystem>("phaseProperties");
const phaseModel& phase
(
fluid.phases()[internalField().group()]
);
const label patchi = patch().index();
// Retrieve turbulence properties from model
const phaseCompressibleTurbulenceModel& turbModel =
db().lookupObject<phaseCompressibleTurbulenceModel>
(
IOobject::groupName(turbulenceModel::propertiesName, phase.name())
);
const scalar Cmu25 = pow025(Cmu_);
const scalarField& y = turbModel.y()[patchi];
const tmp<scalarField> tmuw = turbModel.mu(patchi);
const scalarField& muw = tmuw();
const tmp<scalarField> talphaw = phase.thermo().alpha(patchi);
const scalarField& alphaw = talphaw();
const tmp<volScalarField> tk = turbModel.k();
const volScalarField& k = tk();
const fvPatchScalarField& kw = k.boundaryField()[patchi];
const fvPatchVectorField& Uw = turbModel.U().boundaryField()[patchi];
const scalarField magUp(mag(Uw.patchInternalField() - Uw));
const scalarField magGradUw(mag(Uw.snGrad()));
const fvPatchScalarField& rhow = turbModel.rho().boundaryField()[patchi];
const fvPatchScalarField& hew =
phase.thermo().he().boundaryField()[patchi];
const fvPatchScalarField& Tw =
phase.thermo().T().boundaryField()[patchi];
scalarField Tp(Tw.patchInternalField());
// Heat flux [W/m2] - lagging alphatw
const scalarField qDot
(
(prevAlphat + alphaw)*hew.snGrad()
);
scalarField uTau(Cmu25*sqrt(kw));
scalarField yPlus(uTau*y/(muw/rhow));
scalarField Pr(muw/alphaw);
// Molecular-to-turbulent Prandtl number ratio
scalarField Prat(Pr/Prt_);
// Thermal sublayer thickness
scalarField P(this->Psmooth(Prat));
scalarField yPlusTherm(this->yPlusTherm(P, Prat));
tmp<scalarField> talphatConv(new scalarField(this->size()));
scalarField& alphatConv = talphatConv.ref();
// Populate boundary values
forAll(alphatConv, facei)
{
// Evaluate new effective thermal diffusivity
scalar alphaEff = 0.0;
if (yPlus[facei] < yPlusTherm[facei])
{
scalar A = qDot[facei]*rhow[facei]*uTau[facei]*y[facei];
scalar B = qDot[facei]*Pr[facei]*yPlus[facei];
scalar C = Pr[facei]*0.5*rhow[facei]*uTau[facei]*sqr(magUp[facei]);
alphaEff = A/(B + C + vSmall);
}
else
{
scalar A = qDot[facei]*rhow[facei]*uTau[facei]*y[facei];
scalar B =
qDot[facei]*Prt_*(1.0/kappa_*log(E_*yPlus[facei]) + P[facei]);
scalar magUc =
uTau[facei]/kappa_*log(E_*yPlusTherm[facei]) - mag(Uw[facei]);
scalar C =
0.5*rhow[facei]*uTau[facei]
*(Prt_*sqr(magUp[facei]) + (Pr[facei] - Prt_)*sqr(magUc));
alphaEff = A/(B + C + vSmall);
}
// Update convective heat transfer turbulent thermal diffusivity
alphatConv[facei] = max(0.0, alphaEff - alphaw[facei]);
}
void alphatFixedDmdtWallBoilingWallFunctionFvPatchScalarField::updateCoeffs()
{
if (updated())
{
return;
}
// Lookup the fluid model
const ThermalPhaseChangePhaseSystem
<
MomentumTransferPhaseSystem<twoPhaseSystem>
>& fluid =
refCast
<
const ThermalPhaseChangePhaseSystem
<
MomentumTransferPhaseSystem<twoPhaseSystem>
>
>
(
db().lookupObject<phaseSystem>("phaseProperties")
);
const phaseModel& liquid
(
fluid.phase1().name() == dimensionedInternalField().group()
? fluid.phase1()
: fluid.phase2()
);
const label patchi = patch().index();
// Retrieve turbulence properties from model
const compressibleTurbulenceModel& turbModel =
db().lookupObject<compressibleTurbulenceModel>
(
IOobject::groupName
(
compressibleTurbulenceModel::propertiesName,
dimensionedInternalField().group()
)
);
const scalar Cmu25 = pow025(Cmu_);
const scalarField& y = turbModel.y()[patchi];
const tmp<scalarField> tmuw = turbModel.mu(patchi);
const scalarField& muw = tmuw();
const tmp<scalarField> talphaw = liquid.thermo().alpha(patchi);
const scalarField& alphaw = talphaw();
scalarField& alphatw = *this;
const tmp<volScalarField> tk = turbModel.k();
const volScalarField& k = tk();
const fvPatchScalarField& kw = k.boundaryField()[patchi];
const fvPatchVectorField& Uw = turbModel.U().boundaryField()[patchi];
const scalarField magUp(mag(Uw.patchInternalField() - Uw));
const scalarField magGradUw(mag(Uw.snGrad()));
const fvPatchScalarField& rhow = turbModel.rho().boundaryField()[patchi];
const fvPatchScalarField& hew =
liquid.thermo().he().boundaryField()[patchi];
const fvPatchScalarField& Tw =
liquid.thermo().T().boundaryField()[patchi];
scalarField Tp(Tw.patchInternalField());
// Heat flux [W/m2] - lagging alphatw
const scalarField qDot
(
(alphatw + alphaw)*hew.snGrad()
);
scalarField uTau(Cmu25*sqrt(kw));
scalarField yPlus(uTau*y/(muw/rhow));
scalarField Pr(muw/alphaw);
// Molecular-to-turbulent Prandtl number ratio
scalarField Prat(Pr/Prt_);
// Thermal sublayer thickness
scalarField P(this->Psmooth(Prat));
scalarField yPlusTherm(this->yPlusTherm(P, Prat));
scalarField alphatConv(this->size(), 0.0);
// Populate boundary values
forAll(alphatw, faceI)
{
// Evaluate new effective thermal diffusivity
scalar alphaEff = 0.0;
if (yPlus[faceI] < yPlusTherm[faceI])
{
scalar A = qDot[faceI]*rhow[faceI]*uTau[faceI]*y[faceI];
scalar B = qDot[faceI]*Pr[faceI]*yPlus[faceI];
scalar C = Pr[faceI]*0.5*rhow[faceI]*uTau[faceI]*sqr(magUp[faceI]);
alphaEff = A/(B + C + VSMALL);
}
else
{
scalar A = qDot[faceI]*rhow[faceI]*uTau[faceI]*y[faceI];
scalar B =
qDot[faceI]*Prt_*(1.0/kappa_*log(E_*yPlus[faceI]) + P[faceI]);
scalar magUc =
uTau[faceI]/kappa_*log(E_*yPlusTherm[faceI]) - mag(Uw[faceI]);
scalar C =
0.5*rhow[faceI]*uTau[faceI]
*(Prt_*sqr(magUp[faceI]) + (Pr[faceI] - Prt_)*sqr(magUc));
alphaEff = A/(B + C + VSMALL);
}
// Update convective heat transfer turbulent thermal diffusivity
alphatConv[faceI] = max(0.0, alphaEff - alphaw[faceI]);
}
