A Study of the Ignition Delay of Diesel Fuel Spray Using a Rapid Compression Machine

Abstract

The ignition delay of a diesel fuel was studied using a rapid compression machine that was developed in a previous study. By applying the hot-motored technique proposed by Yu and others, the delay from the start of injection to the onset of exothermic reaction and the delay required to pressure recovery were measured. The sum of the two delays was assumed to be the net ignition delay. Tests were performed for a range of air temperature dependence of the initial delay is low at high temperatures due to physical effects such as heating and vaporization. The pressure recovery delay is largely affected by the fuel-air mixing rate below 750 K. Based on the obtained data, an empirical formula of net ignition delay was proposed.