柴油机起动过程喷雾撞壁试验研究

Experimental Study of Spray-wall Impingement on Diesel Engine Starting Process

基于柴油机油泵试验台设计了可视化定容弹喷雾撞壁试验系统,针对不同粗糙度燃烧室壁面,在起动工况下进行了喷雾撞壁试验,研究了喷油速率、背景气体压力和壁面粗糙度对喷雾撞壁的影响。结果表明:在高喷油速率和低背景气体压力下,喷雾撞壁时刻提前,喷雾撞壁扩散距离增大;在相同喷油速率及背景气体压力下,撞壁扩散距离随壁面粗糙度增大而减小,在喷雾进行3. 0 ms时,喷雾在粗糙度Ra=43μm壁面上的撞壁扩散距离为12. 6mm,在粗糙度Ra=65μm壁面上的撞壁扩散距离为11. 2 mm。

Based on the test platform of diesel engine oil pump,the visualized constant-capacity bomb spray wall impinging system is designed.Under the starting conditions the spray-wall impingement test is carried out which is used to study the effects of injection rate,background gas pressure and wall roughness on spray-wall impingement.The experimental results show that at high injection rate and low background gas pressure,the spray collision time is ahead of time and the spray wall diffusion distance increases.Under the same injection rate and background gas pressure,the spray wall diffusion distance decreases with the increase of wall roughness,and when the spray is 3.0ms,the wall diffusion distance of the spray on the roughness Ra =43μm wall is 12.6mm,and the wall diffusion distance on the roughness Ra=65μm wall is 11.2mm.