combustion bomb simulation ...
 

Hello there:

I am trying to simulation spark ignition of an fuel injection in an initially quiescent combustion chamber (constant volume). The jet (turbulent) passes through a spark plug, which ignites the mixture. The bulk mixture is very lean. The aim is the flame from the fuel jet will help ignite the bulk mixture.

The system is axisymmetric, and I have made the proper adjustments to the k-e model so that the jet will behave "properly". The EDC model is used, with a two-step CH4 reactio mechanism. Yes, I am using CH4 as working fuel.

For some reason, my simulated reaction rate is about 10x faster than my experiments of the same geometry. I suspect that when the flame front penetrates the quiescent bulk fluid, it is moving as if it is a turbulent flame, when it should be more in line with the laminar flame speed. Is there any way I can adjust for this? What other reaction/combustion model can I use?

Thanks very much in advance, Bart.