Correlation of Mixture Formation and Combustion Processes in D.I. Diesel Sprays

Abstract

A micro-hole nozzle and an ultra-high injection pressure were employed to investigate the effects of the nozzle hole diameter and injection pressure on the spray, mixture formation, and combustion processes. The laser absorption-scattering (LAS) technique was adopted to obtain the qualitative and quantitative information on spray characteristics. A high-speed video camera system was employed to record auto-ignition and combustion processes. OH chemiluminescence was used as a marker of auto-ignition and as a measure of the flame lift-off length. The effects of injection parameters on auto-ignition and flame lift-off length were presented. The data on gas entrainment and fuel vaporization acquired in the evaporating sprays under the same ambient conditions were correlated to the auto-ignition process and flame lift-off length.