A Model Widely Predicting Autoignition Time for Gasoline Engines

A model widely predicting auto-ignition time has been developed for gasoline engines. Preliminary decision of optimal spark ignition timing and controller design of spark ignition timing require prediction of the auto-ignition time. The auto-ignition time strongly depends on pressure and temperature in the cylinder, residual gas quantity, air-fuel ratio, and octane number and so on. In order to avoid too complicate model for the on-board implementation, such as detailed chemical kinetic calculation, modified Livengood-Wu integral equation based on Gaussian approximation of residual gas effect and divided into three temperature ranges has been developed.