Flame propagation to lean region in stratified mixture formed by gas fuel jet

Characteristics of the flame propagation into the lean region in the stratified mixture were investigated by the experiments and numerical simulations. In the experiments, gaseous propane was injected into the lean propane-air mixture charge, whose equivalence ratio was less than the lower flammability limit of the premixed mixture. The flame generated in the fuel jet propagated wide into the lean mixture charge region as the stoichiometry of the mixture charge was increased. Then the interactions between the rich flame and the lean mixture were investigated by the numerical simulations of counterflow premixed flame. Reaction rate of the fuel in the lean mixture depended on both opposing gas composition and temperature. These results show the flame in the rich region propagates into the lean region by the "flame inertia" of the rich flame until its relaxation.