I am an undergraduate student and would like to know about extinctions of flames.

firstly, in non-premixed combustion a flame can extinguish if the strain rate is too high (even if the conditions there are otherwise ok for burning). I know the unstrained flamelet model cant deal with this but the strained version can. which other combustion models can deal with flame extinction and which ones cant??? is there any criteria for a model to be able to predict extinction?

secondly, in premixed combustion what is the mechanism by which flames extinguish? how does the strain rate effect these flames? do these flames just locally 'go out' or does the flame just move to areas where it can burn?

any insights or comments would be really useful as I think I am confused.

any insight into this would be hard to do. www.uscomco.org