Abstract
This paper describes a newly developed one-dimensional knocking prediction program. Combustion is forcibly advanced from one side of the cells to trace the input heat release. Unburned cells are compressed by combustion and the Livengood-Wu integral equation is used to judge whether autoignition occurs or not. A higher indicated mean effective pressure was predicted for a stratified air-fuel mixture than for a homogeneous air-fuel mixture in a high-compression-ratio engine because the spark timing for trace knock was advanced. A suitable mixture stratification was found to be a combination of a slightly rich center and a slightly lean periphery. The calculated results corresponded to the experimental data obtained with a single-cylinder engine, especially with regard to the effect of advancing the spark timing for trace knock.
