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-   -   H2/O2 ignition ??? (http://www.cfd-online.com/Forums/fluent/41247-h2-o2-ignition.html)

abel June 3, 2006 10:28

H2/O2 ignition ???
 
Hi I am simulating an h2/o2 diffusion flame using eddy dissipation ( macro mixing). the problem is in the initialisation (numerci ignition) of the h2 and o2 massic fractions. I tried the cold flow for initialisation but after 150 iterations,the message "temperature limited to 5e+03" appears while o2 mass fraction residual go high ...

what could be the problem please........

Ben Lamek June 3, 2006 15:22

Re: H2/O2 ignition ???
 
you need to mix h2 at under 200K and O2 at high temperature. But do you have the polynomila cp(T) of h2 at low temperature. It has been tryed with fluent but ideal gas law (you need compressibility factor varying with pressure) and the lack of cp made the results rubbish. You need a specific code, not fluent for this.

What are you cp?

What is your Lewis number?

Ben Lamek

abel June 8, 2006 05:03

Re: H2/O2 ignition ???
 
Hi Ben my data are as follows:

H2 : T=287 K, V=319 m/s O2 T= 100K , V=2.18 m/s in a coaxial injection.

the problem do not appear when I use PDF chemistry-Turbulence interaction model ???


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