Have anyone known about finite rate mutistep combustion model???? How it difference from eddy-breakup combustion model? and Can I use it for predict auto ignition of compression-ignition engine?

Hi Torn,

You mean global multistep, like 2 or 5 step mechanism? Or you mean 10 to 100 and 1000 number of reactions in a set?

I think, you can use both, you only need to have the set for low temperature region. Most of the commonly used mechanisms and multistep models are overpredicting the rate at low temperatures. I guess you want to look for low temperature mechanisms. The more equations the more difficult but more precise.(OK this statement calls for an argument ))

Difference from EDBR: EDBR doesn't care about the real chemical kinetics, the combustion rate is driven by the turbulence mixing. Chemical kinetics, on the other hand doesn't care about the turbulence mixing rate. You can even put those two models together by comparing the combustion rates, and using the one closer to the real situation. During theignition, chemical kientics is more important, later intense turbulence mixing is probably better choice.

Did I answer your question?

Matej

[sanjeetlimbu]

Dear Sir

I am trying to do autoignition for mixture heptane/N2/O2/AR: 0.562/58/30/10 mole fraction ratio

But unable to do it by any method .. I set the initial T=766K and Presuree= 14.1 bar

1. I tried the laminar rate- it showing error : flat Temp profile, flat profile for presuree



Please guide me how to get autoignition by laminar ... I am in trouble