摘要
在倒拖工况下对四气门发动机气缸内流场进行了实验研究和分析。试验工作是在一台经过改造后的四气门发动机上进行的。采用加长活塞结构及透明活塞顶 ,利用激光多普勒测速仪 (LDA) ,分别对气缸轴线以及燃烧室内和气缸上部两条水平直线上的速度分布进行了测量 ,结果表明 :在进气过程中 ,气缸内产生了双涡结构 ;在压缩过程初期 ,由于从进气门流向排气门侧的滚动涡旋逐渐增强 ,而另一侧的反向涡旋逐渐减弱 ,形成了单一大尺度的滚动涡流 ;在压缩过程中后期 ,滚流经历了加强、衰减、变形和破碎的过程。
The research and analysis of the in-cylinder flow fields in a four valve engine under the motored condition have been carried out. A four valve engine was reformed into an experimental engine with an extended piston and a transparent piston head. The results of the LDA measurements of the gas motion at points on the cylinder axis, and on two horizontal lines in the combustion chamber and in the upper part of the cylinder, show that a twin vortex forms in the cylinder during the intake process, and because of the tumble vortex from the intake valve to the exhaust valve increases gradually and decreases gradually at the opposite side. A single large scale tumble vortex is finally evolved at the initial stage of the compression process after the inlet valves closek. At the middle and later stage of the compression process, the tumble motion experiences a process of enhancement, decay, distortion and breaking up.
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2001年第2期49-52,57,共5页
Chinese Internal Combustion Engine Engineering
基金
国家自然科学基金资助项目
