斯特林发动机压力涡流喷嘴的喷雾特性试验

Experimental Study on Spray Characteristics of Pressure-swirl Nozzle of Stirling Engine

采用高速摄影技术,研究了斯特林发动机压力涡流喷嘴的喷雾发展过程及喷雾特性,并考察了喷射压力和气体引射对喷雾特性的影响.结果表明,压力涡流喷嘴初始喷雾阶段雾化效果较差,持续时间较短,主喷雾发展过程有明显的空气卷吸涡流现象;柴油主喷雾锥角随喷油时间先迅速增大后逐渐减小至稳定,而贯穿距离则逐渐增大至稳定,喷雾锥角随喷油压力的提高而增大;引射空气对稳态喷雾形态有明显影响,使得喷雾扩散范围明显扩大,油气混合更加充分.

In this paper, the atomization process and spray characteristics of pressure-swirl nozzle in Stirling engine were investigated by the high-speed video imaging technique, and the effect of gas ejecting and injection pressure on the atomozation was analyzed. Experimental results showed that the atomization was poor and duration was short in the initial spray stage, while the main spray stage was characterized by air vortex; the spray angle increased quickly with the injection time and then decreased and finally stablized; the tip penetration increased with the injection time before reaching steady state, and the spray cone angle expanded with the increase of injection pressure. With the increase of ejecting air flow, the spray diffusion range was enlarged and the droplet distribution was improved, making the diesel and air better mixed.