Simulation of a supersonic hydrogen–air autoignition-stabilized flame using reduced chemistry

A three-step mechanism for H2-air combustion (Boivin et al., Proc. Comb. Inst. 33 (2010)) was recently designed to reproduce both autoignition and flame propagation, essential in lifted flame stabilization. To study the implications of the use of this reduced chemistry in the context of a turbulent flame simulation, this mechanism has been implemented in a compressible explicit code and applied to the simulation of a supersonic lifted co-flowing hydrogen–air flame. Results are compared with experimental measurements (Cheng et al., C&F (1994)) and simulations using detailed chemistry, showing that the reduced chemistry is very accurate. A new explicit diagnostic to readily identify autoignition regions in the post-processing of a turbulent hydrogen flame simulation is also proposed, based on variables introduced in the development of the reduced chemical mechanism.