Flame Wall-Quenching by Radiation and Conduction in Combustion of Condensed Fuels

Abstract

Abstract The effect of thermal radiation and conduction on the cold-wall flame-quenching distance in the combustion of condensed fuels is studied by use of a simple physical model under steady-state, no-flow conditions. The singular perturbation technique is employed for the flame layer analysis, and the quenching layer is assumed to be optically thin. The quenching distance is obtained as a function of various thermophysical and radiative parameters such as the conduction-radiation ratio, optical thickness and heat generation intensity by chemical reactions. A new dimensionless group, the modified Damkohler number, which characterizes the relative strength of heat generation to radiation transport, emerges from the analysis. Also, the present analysis suggests a potential experimental scheme for measuring the extinction temperature in the specified combustion configurations.