가솔린 분무의 유동 특성에 관한 연구

The injected fuel spray does not have much time to be mixed with inducted air before ignition. Thus it is a important parameter to keep the sufficient spray momentum at the targeting plane. In this paper, the initial spray development of Pintle-type injector was visualized to analyze the atomization characteristics with shadowgraph. The time history of the Sauter mean diameter was obtained with digital image processing technique. Auto-correlation PIV was used to measure droplet velocities and define a spray momentum. The results show that droplet breakup actively takes place at the 20 mm downstream of injector tip and a group of droplets fly 4 msec between 50 mm and 80 mm from injector tip with Sauter mean diameter of about 110μim. The big droplets in the front spray has broken into a lot of small ones with time.