Diffusion Flame Radiative Properties in Gas-Solid Combustion

Abstract

The main purpose of this work is to calculate the radiative properties and the radiative fluxes at each location through a fully developed turbulent boundary layer over a solid reacting surface with a diffusion flame. The radiative properties of gas combustion products are obtained using a spectral method especially well adapted for small scale tests. The initial temperature and species profiles needed are given by the resolution of the conservation equations without radiation. The computed emissivities for various gas mixtures including or not soot are in agreement with previous results. The computational method has been used for different systems: polyethylene or polystyrene with O₂ or air. The results confirm that the contribution of radiation heat transfer to burning rate is negligible compared to convective heat transfer in a laboratory scale test. Radiative heat transfer tends to increase combustion rate only for high soot volume fraction. The values obtained for the various fluxes are in good agreement with the experimental measurements and observations made previously.