Ignition Delay Dependence on Operating Conditions in Diesel Engines

Abstract

Ignition delays were systematically measured under wide and various engine operating conditions, including engine speeds, intake gas temperatures, intake gas pressures, intake oxygen concentrations changed with EGR, fuel injection pressures, and coolant temperatures in a DI diesel engine. An empirical formula to predict the ignition delay based on the Arrhenius equation was obtained with a multiple regression analysis from the experimental results. Ignition delays can be predicted accurately with the final proposed equation, which has three parameters, including the fuel injection pressure as well as the in-cylinder gas temperature and the oxygen partial pressure at the start of fuel injection.