中文摘要：

本文实验研究了水下超声速气体射流气液两相复杂流动。利用高速摄影仪和电子相机分别实时记录了过膨胀超声速工况水下气体射流的喷射状态和整体形貌,显示了不同工况水下高速气体垂直射流的演化过程和动态不稳定性形貌。研究结果表明：在射流的初始段存在与射流内部复杂波系相关的激波反馈特性,激波反馈特性发生之前存在能量积聚的高频低幅的胀鼓过程,二者均随机发生;在射流的主体段,在气水掺混和卷吸大规模能量交换作用下,射流呈现随机的偏摆效应,并且偏摆受环境流场影响明显。

英文摘要：

Gas-liquid complex flows induced by supersonic gas jets are studied experimentally.The gas-jet flow patterns under different over-expanded conditions and the general view are recorded at real time by a high-speed camera and a digital camera respectively,the development process and instable flow of supersonic gas jets at different working conditions are visualized clearly.The experimental results indicate that,shock wave feed back occurs at the zone of flow establishment, before that bulges must be appear as a kind of representation of energy storage with relatively higher frequency and lower amplitude,both shock wave feed back and bulge are occurs at random.At the zone of established flow,the gas jets are wobbling at random due to the effect of large scale energy exchange by gas-water mixing and entrainment,and the wobble effect is affected a lot by environment flow.