Experimental Study on Spectral Characteristics of Kerosene Swirl Combustion

An experimental study has been conducted to investigate characteristics of emission spectra from combustion of kerosene liquid fuel, i.e., jet A-1. Radicals of interest in hydrocarbon combustion are OH*, CH*, and C2*. An experimental study about chemiluminescence characteristics of liquid fuel combustion has been devised to investigate emission characteristics depending on various operating parameters. A swirl combustor is designed for providing similar environments to those of actual liquid rocket engines. The model combustor has a central fuel injector making a hollow cone spray, which is surrounded by swirling flow. Kerosene flame exhibited highly luminous characteristics being attributed to CO2* chemiluminescence. OH* and CH* chemiluminescence intensities show a very similar trend as a function of equivalence ratio. And their intensities decrease along with an increase in equivalence ratio. The chemiluminescence intensity ratios between these two radicals show very close values to one regardless of equivalence ratio. C2* chemiluminescence intensity reveals relatively strong relations with equivalence ratio compared to CH* and OH*. Its intensity values increase as mixture becomes rich and also an increase in inlet air temperature enhances its intensities. The ratios between C2* and CH* manifest a linear relation as a function of equivalence ratio. (C) 2015 The Authors. Published by Elsevier Ltd.