中文摘要：

采用氢气泡流场显示技术，在水槽中对内燃机进气道内流动进行了试验研究。将若干发泡丝布置在进气道进口，接上电源电解水，在流道内拉出多层流面，利用激光片光源对流场打光，通过高清摄像机记录下流动图像。进气道内流动图像表明：由于进气道方转圆和拐弯不够光滑，导致在进气道下游形成流向涡；此外，在进气道出口附近，气门杆后形成的回流堵塞也较大，这些均不利于进气道流通能力的提高。研究结果表明：氢气泡流场显示技术是一种简单有效的研究内燃机进气道内旋涡流动的新方法。

英文摘要：

Using hydrogen-bubble technique flow-field visualization of the internal combustion engine intake port was carried out in a water-tunnel. Several copper wires were positioned at intake port inlet and many sheets of hydrogen-bubble stream were generated when water electrolyzed. The dynamic flow fields were displayed by means of laser-sheet and recorded by a video camera recorder to show the real complex flow in the intake port. It shows that because the port turns not smoothly enough and its section transforms from square to round, there are stream-wise vortex induces downstream in the intake port and much trapped vortex blockage behind valve stems at outlet of the intake port. Those were unfavorable to improve volumetric coefficient of the intake port. It demonstrates that the flow-field visualization technique provides a new simple and effective means to study the intake swirl in internal combustion engine.