Abstract
The effect of a plasma feedstock gas on the composition of combustion products in plasma-assisted combustion was investigated by a spectroscopic measurement of the ethylene (C_2H_4) flame ignited and held by a plasma jet (PJ). Spectra of CH, CN and C_2 were detected in emissions from the flame ignited by N_2 PJ. On the other hand, only CH spectrum was detected in emission of the flame ignited by O_2 PJ. The decrease in the CN emission downstream was much faster than those in CH and C_2 emissions. In the case of N_2 PJ, an increase in the electric power to the PJ torch decreased the flame length.
