On the Quenching of a Diffusion Flame Near a Cold Wall

Abstract

High activation energy asymptotic methods are used to derive an expression for the quenching distance for a diffusion flame undergoing the one-step irreversible reaction F + vO → P near a cold wall. The fluid-dynamic influences are disregarded by assuming a very small mass flux. The two-dimensionality of the problem is retained. This requires analysis of the temperature field in the pure (one-dimensional) diffusion flame region, in the pure premised flame regions, in the pure quenching region and in the so-called “Iriple-poinl region” where all of these separate zones meet. The functional form for the quenching distance is identical to that obtained by a simplified one-dimensional analysis; a larger numerical multiplicative factor accounts for the multidimensionality.