Radiation Transfer Between Flame Burning Zone and Unburned Fuel.

摘要

A fuel continues to burn by the heat returned from the flame to the unburned fuel. The heat transferred by radiation is dependent upon the intensities of the flame emission spectru,the fuel absorption,and especially on the overlap,or product,of the two spectra. The product of the two spectra was calculated point by point through the near infrared (2microns to 6microns) and integrated over wavelength for 14fuels,primarily hydrocarbons. In general,maximum overlap occurs in the regions of CO2and H2O emission bands. Overlap values vary from 3.19 x 10to the -6th power for methane to 0.178for unsymmetrical dimethylhydrazine. The overlap is shown to closely approximate the total radiation intensity absorbed by the fuel and is demonstrated to be linearly related to the fuel regression rate. Assumption of graybody absorption and emission are found to be poor approximations for those heat transfer processes. Methods are discussed for enhancing overlap and thereby the rate of energy release by the flame. (Author)