Simulation Study of Injection Strategy and Tumble Effect on the Mixture Formation and Spray Impingement in a Gasoline Direct Injection Engine

A three dimensional model of 2.0L, turbocharged gasoline direct injection (GDI) engine was established using AVL-Fire. The mixture formation process and spray impingement were analyzed with various injection strategies. The results showed that, as the injection timing delay, the amount of spray impingement reduces and the mixture at the ignition timing is less homogeneous. Compared with the single-stage injection, the dual-stage injection could reduce the amount of spray impingement. The intakeports were designed to obtain high tumble ratio, then the formation of mixture in cylinder was simulated to study the effect of tumble ratio on spray impingement and mixture formation process. It turned out that the intakeports with higher tumble ratio could get better mixture formation and less amount of spray impingement.