中文摘要：

为研究二维水槽中高速气体射流的振荡流流型，建立了一套操作方便、可重复性好的实验系统。利用高速摄影仪研究了水下高速气体射流的形貌，显示了气体逆流而上撞击喷口表面的回击现象，发现了在喷口附近间歇性产生的胀鼓现象。结果表明：湍流气／水界面仍然存在于过膨胀射流中；射流在回击之前总是发生多次的膨胀，并且膨胀次数越多、膨胀幅度越大，回击的强度越高，对喷口表面的蚀损就越严重；超音速工况时的回击频率约为5．3Hz。

英文摘要：

This paper describes an experimental study on the vibrating flow characteristics of twodimensional submerged high-speed gas jets. A convenient and repeatable experimental system is established. By using a high-speed camera, the image of flow patterns for the high-speed gas jets in water is obtained and the so-called back-attack and bulge phenomenon are found. The experimental results indicate that, the turbulent boundary of the gas-water still exists in over-expanded jet. Bulging of jet occurs many times before occurrence of back-attack, and the intensity of back-attack increases with increasing bulge frequency and intensity. The frequency of back-attack is 5. 3Hz in case of supersonic underwater gas jet flow.