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Michal September 18, 2001 09:07

Species Concentration

Is it possible to obtain a concentration of species directly from a solver for a UDF purposes?


KT September 18, 2001 17:16

Re: Species Concentration
Yes, you can use C_YI(c,t,i), where c is the cell, t is the thread, and i the species index.

Michal September 19, 2001 01:48

Re: Species Concentration
Thanks for Your response! One mor question: How to check which species index "i" describe particular species? Michal

KT September 20, 2001 14:40

Re: Species Concentration
It usually corresponds to the species list in the material panel starting with 0.

Greg Perkins September 24, 2001 02:48

Re: Species Concentration
Note C_YI returns the species mass fraction not concentration. You will need to convert to get concentration.


Michal September 25, 2001 02:32

Re: Species Concentration
Thanks for Your advices!

Another question: How to get a mixture density for UDF directly from a solver? Is it correctly to obtain this value simply by C_R(c,t)?

Greg Perkins September 25, 2001 03:45

Re: Species Concentration

so a species concentration is

CONC_i = C_YI(c,t,i)*C_R(c,t)/Mi

where Mi = molecular weight g/mol = kg/kmol of species i


Michal September 25, 2001 03:52

Re: Species Concentration
Thanks for Your very helpful answer! Now it is clear...


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