가솔린 엔진용 2홀 2분류와 4홀 2분류 타입 인젝터의 액적 평균 직경의 동적 거동 비교

Comparison of Dynamic Behavior of Droplet Mean Diameter with 2holes-2sprays and 4holes-2sprays Types Injector for Gasoline Engine

The influence of fuel spray characteristics on engine performance has been known as one of the major concerns to Improve fuel economy and to reduce exhaust emissions. In general, the UBHC(Unburned Hydrocarbon) emission could be reduced by decreasing the droplet size of the fuel sprays. In PFI (Port Fuel Injection) gasoline engines, the mixture of air and fuel would not be uniform under a certain condition, because the breakup and production of spray droplets are made in a short distance between the fuel injector and intake valve sheat. In this study, were investigated the transient spray characteristics and dynamic behavior of droplets from 2holes-2sprays and 4holes-2sprays type injectors used in PFI gasoline engine. Mean droplet size and optical concentration were measured by LDPA (Laser Diffraction Particle size Analyzer). The variation of droplet mean diameter and optical concentration were measured for understanding the behavior of unsteady spray.