The Response of Premixed Flames to Pressure Perturbations

Abstract

Abstract The response of a premixed laminar flame lo small perturbations in pressure, with characteristic times comparable to the natural time scale of the flame, is studied within the coniext of the Near-Equidif-fusional Flame (NEF) theory. The main emphasis is on flame extinction. It is found that small dynamic variations in pressure, of the order of the reciprocal of the activation energy, have a substantial influence on the burning rate, and may even cause it to drop to zero (extinction). This is in contrast to an earlier study due to Peters and Ludford, which considered only slow variations in pressure, and concluded that substantially larger pressure variations, of the same order as the ambient pressure, would be needed to quench the flame.