The structure of inhibited counterflowing nonpremixed flames

Numerical simulations of the structure of laminar counterflow methane-air nonpremixed flames with chemical (chloromethane) and inert (nitrogen) agents added to the oxidizer stream were performed using a previously developed computer code. The computations were substantiated by measurements of the temperature and velocity fields. The simulated flame structure demonstrated that the addition of chloromethane to the oxidizer side of a nonpremixed flame leads to a broadened reaction zone, increased flame temperatures, decreased concentrations of key flame radicals, and decreased rates of important exothermic chemical reactions. The addition of nitrogen to the oxidizer side of the flame had a very different impact on the flame structure, leading to decreased flame temperatures and decreased concentrations of key flame radicals. The reaction pathways associated with inhibition by chloromethane were identified through an analysis of the calculated flame structure. Simulated flames inhibited by molecular chlorine and hydrochloric acid are also discussed.