Study on Ignition Delay in High Turbo-charged Diesel Engines

Abstract

Ignition delay of diesel fuel sprays is investigated experimentally using a rapid compression-expansion machine at operating conditions of high turbo-charged DI diesel engines. A comparison of experimental results with published data shows that higher cylinder pressure can shorten ignition delay under the high pressure injection. Since this results in effects of both higher cylinder pressure and higher charged oxygen amount, we tried to examine independently the effect of each factor on ignition delay shortening at higher surrounding air pressure. The results shows that an increase in charged oxygen amount at constant surrounding gas pressure results in a drastic decrease in ignition delay, and an increase is surrounding gas pressure at constant charged oxygen amount results in a slight increase in ignition delay below the gas temperature of 900 K.