CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   molar concentration marco (http://www.cfd-online.com/Forums/fluent/31474-molar-concentration-marco.html)

rookie May 14, 2003 12:14

molar concentration marco
 
Hello,

In the multispecies model, we can retrieve species mass fraction using C_YI(c, t, i). Does anyone know what is the marco to retrieve specie molar concentration something like C_YI?

Thank you!

Andrew Garrard May 15, 2003 08:23

Re: molar concentration marco
 

Andrew Garrard May 15, 2003 08:29

Re: molar concentration marco
 
I don't know if you can get the UDF to pull out the molar concentration or not. I believe that fluent calculates the mass fraction during the iterative process and then converts this to a molar concentration when requested, for example in a contour plot. You can get your UDF to produce a molar concentration by multiplying the mass fraction by the density and dividing by the molecular weight something like

mol_conc = yi[0] * C_R(c, t) / mw[0];

I don't know if that will you will have to play around with it, but that is how I intend to produce the molar concentration.

rookie June 12, 2003 20:51

Re: molar concentration marco
 
Hello Andrew,

Your idea works! Thank you a lot.

Rookie


All times are GMT -4. The time now is 12:17.