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Ancioi January 31, 2012 08:53

Ideal Gas Mixture, non reacting
Dear all,

I'm a newbie in OOP programming and numerical modelling. I'm trying to simulate a gas mixture flowing in a complex 3D geometry, but I don't know how to write my thermophysical model. I tried to learn something from the forum but I didn't find a clear response.

I have a gas mixture of: 90% Helium, 9% N2 and 1% Xenon. I would like to use the ideal gas law to calculate rho during the numerical simulation.

I thought something like:

thermoType thermoModel<pureMixture<constTransport<specieTermo<hConstTermo<perfectGass>>>>>;
What kind of thermoModel could I use?Have I to write another file to define the different species?How could I define the different species?

Thanks in advance

Ancioi February 1, 2012 06:19

1 Attachment(s)
About my previous question,

I send you in attachment my ThermophysicalProperties file. I guess should be right, but my doubt is that in this way I have an homogeneous mixture. And this is not what I want, because I have inhomogenoeus mix.

Where can I define my rho... something like rho=0.9*rho_He+0.09*rho_N2+0.01*rho_Xe, or maybe define the partial pressure?

I look forward to hearing you

markusrehm February 2, 2012 08:55


have a look at the combustion examples there you will find how to define mass or volume fractions.


gork March 19, 2013 12:49

Dear Foamers,

I have a similar problem in finding a thermophysical model for the simulation of an inert mixture of gases. All I want is to use temperature dependent thermophysical properties of a gas mixture where I can arbitrarily define its composition.

I am so far as to believe that this must be either trivial or very hard, because all I can find concerning this topic are threads like this, where the answer is rather unsatisfying.

Do I understand correctly that the pureMixture model is not capable of treating mixtures the way I want?

Looking at the combustion tutorials did not help me very much to be honest, because those are dealing with chemical reactions - or is it a common workaround to use those models without chemical reaction?

thanks in advance, best regards


Henning86 April 12, 2013 06:52

im working on a simliar problem i need a mixture of different gases. But the puremixture is not supporting that.

Im trying now to implement the combustionthermodynamics in rhoCentralFoam.

has anyone experience with that?

immortality April 12, 2013 07:10

i also want to model a compound of gases without well as question that propounded i have a question that
Which combination should i choose for gases coming out from a typical gas turbine combustion chamber? I want to analyze this compound to another device without any combustion or reaction.

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