How to understand "Y[inertIndex] = scalar(1) - Yt" in YEqn.H
 

Hi Foamers:
As we can see the following codes in YEqn.H:

{
label inertIndex = -1;
volScalarField Yt(0.0*Y[0]);
forAll(Y, i)
{
if (Y[i].name() != inertSpecie)
{
volScalarField& Yi = Y[i];
solve
(
fvm::ddt(rho, Yi)
+ mvConvection->fvmDiv(phi, Yi)
- fvm::laplacian(turbulence->muEff(), Yi)
==
kappa*chemistry.RR(i),
mesh.solver("Yi")
);
Yi.max(0.0);
Yt += Yi;
}
else
{
inertIndex = i;
}
}
Y[inertIndex] = scalar(1) - Yt;
Y[inertIndex].max(0.0);
}
What does the "Y[inertIndex]"meas?How can I understand it?and what does the "Y[inertIndex]"use?
Thanks in advance!

I guess:
It is mass fraction of the inert species.
For example the N2 mass fraction in the following:
CH4+2(O2+3.76N2) --> CO2+2H2O+7.52N2

Thanks Moslem,I think you are right!

what is Yt ?
 

Hi people ,
can u explain me what is Yt
initialised in the code as -
volScalarField Yt(0.0*Y[0]);

Y_total exclude the inertSpecie

thnx zhanGyan