in fluent, it recommended that if the reaction chemistry is stiff, it's better to turn on the stiff-chemistry solver by solver-->set-->stiff-chemistry. did anyone ever use it before? i tried, but didn't activate it, the path in the manual doesn't seem to be right.

Hi,

Which combustion model are you using? I suppose the finite rate chemistry model. If yes, then you can switch it on at the bottom of where you will choose the finite rate chemistry model.

Hope this helps.

James