Abstract:The two-fluid method using linear cavitation model was utilized to simulate GDI multi-hole injector nozzle flow. The evolutionary law of the cavitation flow pattern was analyzed. Cavitation criterions were summarized and compared. Results showed that cavitation was formed at the hole corner and the gap between the moving needle and valve seat. Cavitation flow pattern was unstable and changed with time. Nozzle flow rate decreased and while exit velocity increased due to the cavitation. Also each hole flow rate was different. The critical cavitation number was efficient to predict the cavitation. The non-cavitation flow of GDI multi-hole injector could only be appeared when the injector worked in low injection pressure and high ambient pressure for stratified combustion applications.