Ansys Employee

Your mesh isn't fine enough for the physics: you need significant refinement for the combustion region. Also, we generally recommend hex or poly (not available in R17) elements for accuracy: combustion calculations tend to be very stiff (reaction rate is tightly coupled with temperaure and vice versa). 

I don't know what you mean by "law". The combustion models may have limiters but they're for extreme cases and shouldn't be used "just because". Fix the mesh before messing with numerical stabilisation functions.