Infrared flame radiation

Abstract

Gaseous and particulate absorption for a non-homogeneous medium is considered both analytically and experimentally. A simple peak partial pressure and peak temperature scaling method applicable to combustion zones is successfully employed for non-homogeneous intensity calculations. Experimentally, natural convection controlled diffusion flame radiation is investigated. Spectral measurements of the radiance and transmittance are reported for polystyrene, Delrin, and Plexiglas fuels. The homogeneous gray model is shown to predict the experimental results reasonably well, yet is useful only when experimental data exist. The homogeneous nongray approximation is found to be inapplicable to highly non-homogeneous pathlengths. Non-homogeneous nongray calculations are shown to be accurate and with the peak partial pressure and peak temperature scaling method, simple calculations are possible from fundamental properties of the flames.