Study of Infrared CO₂ Radiation From Liquid-Fueled Combustor

Measurements of CO₂ infrared radiation were performed on exhaust gases from a combustor. The combustor is a 30% flat (rectangular) model of an annular turbojet-engine combustion chamber. This is a turbulent non-premixed kerosene-air flame with equivalence ratios within the range of 0.15–0.75. The infrared radiation images are obtained by a IR camera equipped with a narrow bandpass filter that falls on the CO₂ fundamental band. Temperature profiles were measured by thermocouple at the combustor outlet. The INFRAD program was used to calculate infrared radiation from the CO₂ gas component of the exhaust gases from the combustor. The simulation was performed, taking into account the effects of radiation emission and absorption along an optical path. The calculations allow prediction of apparent gas temperatures using the IR camera readings. The calculated results are compared with experimental measurements. They are found to be in reasonable agreement.