Numerical simulation of laminar stoichiometric hydrogen–air flame structure

Numerical simulations of flame structure and laminar burning velocity are performed for a stoichiometric hydrogen–air mixture under standard initial conditions. A comparative analysis is presented of the results obtained using three detailed kinetic mechanisms (DKMs), which differ both in the set of elementary reaction steps and reacting species and in the values of rate constants. It is found that the decrease in H2 concentration has a weakly pronounced two-stage character. In the presence of an additional initiation channel H2+O2=OH+OH, a pronounced second maximum of the intermediate H2O2 concentration appears. In the absence of this channel, a two-stage increase in OH concentration is observed. Based on an analysis of the sensitivity of heat release to reaction rate constants, the complex behavior of the OH and H2O2 profiles is explained. Despite the differences revealed, all three DKMs predict similar values of burning velocity and heat release rate.