A theoretical analysis of premixed flame propagation with an isothermal chain reaction

Abstract

An asymptotic analysis, for large activation energies, is presented of the structure of a deflagration wave supported by a two step chemical reaction mechanism with a first order chain-branching reaction and a second order chain termination reaction. In the first step the initial reactant is transformed, without liberation of heat, into an intermediate species; the reaction is auto-catalytic and has a large activation energy. In the second step the intermediate species recombines, with liberation of heat, to give the final products. Three main regimes are found in the analysis. For low recombination rates, an isothermal chain reaction flame precedes a much thicker recombination region where transport effects may be neglected.