Find Equivalence ratio in CHEMKIN

  • Last Post 14 March 2018
  • Topic Is Solved
Karna posted this 13 March 2018

How can I find equivalence ratio in CHEMKIN if I know the moles of fuel, oxidizer and other species? 

I have reactants as follow.

a*C2H2 + b*H2 + c*(O2+3.76N2) + d*CO2 + e*N2 -----> products

Where, a=0.3124, b=1.6776, c=2.1958, d=0.3702, e=1.483792

What will be an equivelence ratio for the above equation? 


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pgl posted this 14 March 2018

There's a great example of finding the equivalence ratio in our online help here.  That example is for the combustion of Propane in Air.

If you don't have access to our online help, you can look at Page 25 of this PDF.   

Good luck. Tell us if this helped?




Karna posted this 14 March 2018


In the manual, the given example is for simple propane air combustion and for that stoichiometric equation is easy to build. But what if we have a complicated combustion reaction with multiple fuels and multiple oxidizers as I wrote in my initial question and you don't know stochiometric reaction for that?

Basically, to find out equivalence ratio you need numerator and denominator. The numerator is related to fuel/oxidizer value at specific state which is easy to figure out in my question. However, denominator part is related to a stoichiometric condition, which I don't know in my case since this is not a simple prepare air combustion as stated in the manual. How can chemkin be useful in this case to find out equivalence ratio? 


In other words, how can I get the equivelence ratio from chemkin when I don't know the stoichiometric equation (denominator part of the equivalence ratio)?