中文摘要：

用射钉枪和一级轻气炮对高速物体（细长体）出入水时的超空泡流动现象进行了实验研究，并用高速摄影仪拍摄了相关流场．研究表明，由气泡组成的超空泡尾部的尾涡呈周期性脱落．在出水过程中，物体的速度总体上是在减小的；但是在出水后，如果水花喷溅到物体尾部，物体会获得一定程度的短暂加速．在入水过程中，物体与空泡壁面的碰撞以及非对称性空泡脱落，会导致水下物体的弹道发生变化．根据实验结果，测量了入水后物体的阻力系数Cd，Ca≈0．7～1．2．

英文摘要：

Using a pneumatic gun and a single stage light gas gun, the supercavitation phenomena during water entry and exit of high-speed bodies （slender Bodies） were investigated experimentally. The flow fields were visualized by a high speed camera. The study shows that the trailing vortices consisting of small bubbles shed periodically behind a supercavity. During water exit, the bodies＇ velocities decrease generally, but a short acceleration may occur when the water splash impacts on the bottom of the body. During water entry, the hydroballistics of the underwater body may change due to the asymmetric bubble shedding behind the body and the collision between the body and the cavity＇s wall. According to experimental results, the drag coefficient in water Ca was measured, and Cd≈0. 7-1.2.