Superequilibrium O concentrations and prompt NO formation in laminar premixed methane-air flames

Superequilibrium concentrations of oxygen atoms which enhance the productio n of prompt NO in laminar premixed methane-air flames are usually computed using elaborate flame codes. This paper presents a simple method to compute superequilibrium O atom concentrations and simplifies the prompt NO mechan ism using steady state relationships such that the flamefront NO production depends solely on the rates of just 3 reactions. The results show that the contribution of the N2O mechanism to the total NO increases dramatically w ith pressure and that the Fenimore mechanism is more important than the Zel dovich and N2O pathways in the cooler regions of the flame.