A question about hEqn.H in reactingFoam
 

Hi Foamers:
There is a term of "chemistrySh" in energy equation in reactingFoam,I think it is reacting source term,but what the term represents ?Is there any theroy corresponging to "chemistrySh".I have no idea with the following codes:
Info<< "Solving chemistry" << endl;
chemistry.solve
(
runTime.value() - runTime.deltaTValue(),
runTime.deltaTValue()
);
// turbulent time scale
if (turbulentReaction)
{
tmp<volScalarField> tepsilon(turbulence->epsilon());
const volScalarField& epsilon = tepsilon();
tmp<volScalarField> tmuEff(turbulence->muEff());
const volScalarField& muEff = tmuEff();
tmp<volScalarField> ttc(chemistry.tc());
const volScalarField& tc = ttc();
forAll(epsilon, i)
{
if (epsilon[i] > 0)
{
// Chalmers PaSR model
scalar tk = Cmix.value()*Foam::sqrt(muEff[i]/rho[i]/epsilon[i]);
kappa[i] =
(runTime.deltaTValue() + tc[i])
/(runTime.deltaTValue() + tc[i] + tk);
}
else
{
// Return to laminar combustion
kappa[i] = 1.0;
}
}
}
else
{
kappa = 1.0;
}
chemistrySh = kappa*chemistry.Sh()();
}