does nonequilibrium density include ionization?

[CatarinaGarbacz]

Hi, I want to use Mutation++ to compute the density of a mixture in thermal and chemical nonequilibrium. I see we have this function available

double Thermodynamics::density(const double T, const double P, const double const X) const { double density = 0.0; for (int i = 0; i < nGas(); ++i) density += X[i] speciesMw(i); density = P / (RU T); return density; }

from my understanding, this only works if there are no electrons in the mixture since for electrons we would consider Tve instead of T. I am correct ?

Thank you

[jbscoggi]

Hey @CatarinaGarbacz, the easiest approach is just to use the state model that you want (Like ChemNonEqTTv) and then call the mixture.density() function after setting the state. That should be what need I think.

[CatarinaGarbacz]

Hi JB thanks for answering.

I am not so sure, but let me explain you better the specifics of what I'm looking for.

I want to compute the density at the flow initialization stage, where I have mass fractions, pressure and temperatures. to set the state of the mixture for the model ChemNonEqTTv, I first need to compute the density through the "nonequilibrium" equation of state (since the inputs for setstate include species densities). so I need to compute the density explicitly beforehand... and I don't see how that formula would account for electrons in the mixture... but if I'm wrong or if there's another way to account for electrons, I'm all ears :)

[jbscoggi]

Ah OK I understand now, yes I think that is an edge case that is not currently implemented. If the temperatures are equal, then you could just use the function you mentioned before, but if they are not, then it would not work. It should be easy enough to implement this though.

[CatarinaGarbacz]

makes sense! I'm not gonna implement this now since I'm full on developing on SU2, but actually I will take note of these little things that would me useful in Mutation++ and I might do it in the future, once things are more solid in SU2.

thanks again