ON THE AUTOIGNITION AND COMBUSTION CHARACTERISTICS OF KEROSENE DROPLETS AT ELEVATED PRESSURE AND TEMPERATURE

Abstract

The effects of high ambient pressure and temperature were experimentally investigated on the autoignition delay times of isolated kerosene fuel droplets. The droplet was hanged at the tip of a quartz fiber and suddenly exposed to high ambient temperature by the help of falling electric furnace at desired ambient pressures under normal gravity. The ignition was detected visually by the use of high-speed photography. Results have shown that the autoignition delay time decreases with an increase in both temperature and pressure. Also an increase in ambient pressure reduces the ignition location distance from the droplet. The experimental results of autoignition delay times were correlated with the equation τ = AP^Bexp(D/T). The combustion of the kerosene droplet was also investigated at various ambient temperatures and at atmospheric pressure. The droplet burning rate was calculated using temporal histories of droplet diameter. The droplet combustion followed d ²-law. And a comparison between evaporation and burning rate constants has shown that their difference reduces at higher ambient temperatures.

Keywords:

• Autoignition
• Combustion
• Droplet
• High pressure
• High temperature
• Kerosene

The study was supported by the CEFV (Center for Environmentally Friendly Vehicle) of Eco-STAR project from MOE (Ministry of Environment, Republic of Korea).