Numerical Analysis of Mixture Formation of a Direct Injection Gasoline Engine(<Special Issue>Recent Combustion Technology in Internal Combustion Engines)

A direct injection gasoline engine employing a new stratified combustion system has been developed. A fan-shaped fuel spray and a shell-shaped piston cavity achieved the combustion strategy. The process of stratified mixture formation and consequent stratified combustion is affected by the fuel spray characteristics, therefore numerical analysis (CFD) was applied to understand the phenomena of mixture formation process. From the results of CFD, it was clarified that the vaporization characteristic is important in realizing a suitable stratified mixture formation, in addition to the spray liquid characteristics, and CFD enables prediction and analysis of actual phenomena.