Flame Propagation Through Atmospheres Involving Concentration Gradients Formed by Mass Transfer Phenomena

Abstract

The purpose of the present work is to establish experimentally the nature of the phenomena and the rate of fire spread through explosive media involving concentration gradients in a fuel-air mixture. Most of the work reported has been limited to upward flame propagation using methane as a fuel. Wide deviations from the quasi-steady approach were observed when a flame propagates along a negative concentration gradient in lean methane-air mixtures. It appears that the observed rate of fire spread in stratified lean mixtures can be correlated directly in terms of local concentration gradients and the corresponding propagation rates under homogeneous conditions.