Study on the Primary breakup of Fuel Spray in Multi-hole Injector for Direct Injection Gasoline engines

Abstract

In recent years, Computational Fluid Dynamics (CFD) has been widely used in engine development, and it is known that the accuracy of the droplet breakup model has a great influence on the modeling of fuel sprays in CFD. In this laboratory, WAVE-MTAB model is used as a droplet breakup model for gasoline spray and its applicability is verified. However, WAVE-MTAB model was developed for diesel sprays, and it is reported to have limitations in its applicability to gasoline engines that inject relatively low pressure fuel. The purpose of this study is to elucidate the primary breakup form of the fuel spray in the multi-hole injector for direct gasoline injection, and to develop a breakup model that corresponds to the actual phenomenon. In order to visualize the primary breakup process of the fuel spray under low injection pressure conditions, we took enlarged images of the spray near the nozzle hole using a high-speed camera and microscope lens.