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Ideal Gas Mixture, non reacting

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Old   January 31, 2012, 08:53
Default Ideal Gas Mixture, non reacting
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Francesco Borgosano
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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:
Code:
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
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Old   February 1, 2012, 06:19
Default ThermophysicalProperties
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Francesco Borgosano
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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
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File Type: txt thermophysicalProperties.txt (1.7 KB, 45 views)
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Old   February 2, 2012, 08:55
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Markus Rehm
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Hello

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

Markus
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Old   March 19, 2013, 12:49
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Georg Brösigke
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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

Georg
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Old   April 12, 2013, 06:52
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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?
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Old   April 12, 2013, 07:10
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Ehsan
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i also want to model a compound of gases without reaction.as 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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