CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CD-adapco (
-   -   Distribution of Phi (Equivalence ratio) (

Mahbub December 30, 2003 23:50

Distribution of Phi (Equivalence ratio)
I'm trying to simulate the mixture of Air and Methane in a combustion chamber. How can I get the distribution of Phi (Equivalence ratio)?

Lars Ola Liavåg December 31, 2003 02:00

Re: Distribution of Phi (Equivalence ratio)
Hello Mahbub,

Try PROSTAR's operate command. If your methane fuel is scalar #1 and any residual gases are scalar #2, you could use:

*set,afst,17.20105 ! stoichiometric A/F ratio

oper,getc,conc,5,1 $oper,getc,conc,6,2

oper,add,5,6,4 $oper,ssub,1,4,4 $oper,divi,4,5,4


Best regards, Lars Ola

Mahbub January 2, 2004 13:20

Re: Distribution of Phi (Equivalence ratio)
Hi Lars, Thanks a lot. Would you please tell me the unit of that scalar concentration?

Lars Ola Liavåg January 5, 2004 01:47

Re: Distribution of Phi (Equivalence ratio)
Hello Mahbub,

I'm personally using SI units but the equivalence ratio is anyway a dimensionless quantity. The inputs are the scalar mass fractions as obtained directly from STAR-CD and the stoichiometric air/fuel (mass) ratio, which is also dimensionless.


Lars Ola

All times are GMT -4. The time now is 00:01.