The influence of the Lewis number on the propagation of a plane thermal wave

Abstract

The results of a numerical calculating of the propagation of plane wave of reaction described by the equations of one-dimensional unsteady heat conduction and diffusion are presented. To describe the rates of energy supply and the change in mixture composition, macrokinetic equations are used. The set of dimensionless variables used is such that, in the simplest case (when thermal parameters and density are constant), only the igniter temperature, the initial temperature of the mixture and the ratio of activation energy to calorific value of a fuel, have a decisive influence on the propagation process. The reaction rate constant enters only in the recount of results into physical variables and does not affect the stability limits. In the range of Lewis numbers from 0 to 1, stationary, oscillatory, and pulsating modes of reaction wave propagation are obtained. The boundaries that determine the types of the propagating thermal waves are constructed.