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-   -   2 Step Methane-Air Chemistry Model (http://www.cfd-online.com/Forums/fluent/28930-2-step-methane-air-chemistry-model.html)

Prateep Chatterjee September 18, 2001 10:52

2 Step Methane-Air Chemistry Model
 
I've been using the single step chemistry model for methane combustion for quite long and along with the segregated solver, have been successful in simulating unsteady laminar combustion processes.

I tried using the two step model, but wasn't able to ignite the premix charge. didn't turn on backward reactions. even though the interest region is lean premix combustion, I tried a stoichiometric mixture so that the ignition process would be easier.

suggestions from the CFD gurus please! need to work with multiple step chemistry, and starting with a 2 step model is definitely in my agenda.

Marc Whale September 21, 2001 11:01

Re: 2 Step Methane-Air Chemistry Model
 
did you turned on :

cp ( mixture ) = mixing law

cp ( every species ) = piacewise - polinomial

?? Try, along with setting for viscosity and density

Marc

Erwin September 22, 2001 13:00

Re: 2 Step Methane-Air Chemistry Model
 
I have run into similar problems. I've used two different ways to get the combustion going:

1 - Initialize flow field with temperatures higher than auto-ignition temperature.

2 - Start using the eddy-dissipation model only. This will burn the fuel instantly as it mixes with the oxygen. Later turn on Magnussen model to include kinetics.


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