中文摘要：

在水洞中采用氢气泡流场显示技术对发动机气缸内流动进行了试验研究.结果表明,在不同气门升程下,缸内流动结构整体上是相同的.离缸盖底面越近,进气道出口射流形成的旋涡数目越多.随着观察截面远离缸盖底面,旋涡逐渐汇合,且旋涡强度不断减弱,最终演变为双涡结构.气门升程越小,气缸内双涡结构出现的位置离缸盖底面越近.氢气泡流场显示技术为研究发动机缸内旋涡流动提供了一种简单有效的方法.

英文摘要：

The technique of hydrogen-bubble flow visualization in a water-tunnel is adopted to conduct an experimental study on the in-cylinder flow of engine.The results show that by and large the flow structure in cylinder is almost identical at different valve lifts.With the section moving closer to the cylinder top plane,the number of vortex generated by the jet-flow at intake duct outlet increases; and with the section moving away from cylinder top plane,the vortexes gradually merge with their intensity weakening and finally form a double vortex structure,which is closer to cylinder top plane at smaller valve lift.The flow-field visualization technique provides a simple and effective way for studying the vortex flow in the cylinders of an engine.