On the structure of premixed and diffusion laminar spherico symmetrical flames

Abstract

Premixed and diffusion laminar spherico-symmetrical flames are studied by means of a non-adiabatic model which considers variable temperature at infinity. The flame is supposed to be maintained by a porous sphere through which the gaseous mixture or one of the reactant gases is injected. Stationary conditions are assumed and chemical kinetics of the process is approximated by means of an overall reaction rate. Solution of the problem is achieved by means of an approximate analytical method. Flame temperature, mass flow per unit area at the flame surface, thickness and radius of the flame and temperature at the sphere surface are given as functions of the mass flow. The influence of the main parameters of the process: temperature at infinity, dimensionless ratio of the activation energy to the heat of reaction and sphere radius is also considered. Some experimental results for diffusion flames are also given in the paper.