钝体倾斜和垂直冲击入水时引起的超空泡流动特性实验研究

对4种不同头型的钝体、以不同初始速度在小倾斜角度和垂直状态下入水，所产生的空泡流进行了的实验观察，分析了不同工况下空泡产生和发展的特性。实验结果表明:对于倾斜入水及垂直入水，圆台头和平头(即空化器均为圆盘)实验体均能形成较稳定的入水弹道；初始入水速度较低时，空泡的闭合方式为深闭合；初始入水速度较高时，空泡的闭合方式为表面闭合，且运动速度衰减得更快。测量得知，钝体倾斜入水产生的空泡的前部外形轮廓与Logvinovich的半经验公式给出的结果相吻合。在垂直入水的情况下，调查了物体头部对空泡的起始点位置及其形态的影响。

Experimental study of supercavitating flows induced by oblique and vertical water entry of blunt bodies

Small-angle oblique and vertical water entry experiments were carried out to observe the supercavitation generated by the blunt bodies with different initial velocities. The development features of the supercavitation in different cases were analyzed. Experimental results show that for small-angle oblique and vertical water entry, the the round-head and flat-head (disc cavitator) blunt bodies can form stable trajectories. When the initial water-entry velocity is lower, the closure mode of the cavity is deep closure. When the initial water-entry velocity is higher, the closure mode of the cavity is surface closure, and its speed decay rate is larger. For the supercavity generated by the small-angle oblique water entry of the blunt bodies, the front part of the supercavity contour is in agreement with the result by G.V. Logvinovich's semi-empirical formula. For the vertical water entry of the blunt bodies, the influences of the head shapes were discussed on the beginning points and morphologies of the supercavities.