空气域压力对高速射弹入水流场影响

Effects of operating pressure on high-speed projectile's water-entry flow

为研究空气域压力对射弹入水流场的影响,采用流体体积法(VOF)多相流模型对锥头圆柱体高速入水过程进行数值模拟,得到射弹入水速度与入水深度以及空泡形态的分析结果,并将数值模拟结果与基于牛顿第二定律和文献的理论结果进行对比,验证数值方法的正确性.基于该方法针对不同空气域压力条件对入水过程进行分析,结果表明空气域压力对自由液面上方的喷溅形态、空泡表面闭合时间以及空泡内部空化效应影响较大.空气域压力越大,空泡敞开阶段的空泡口处半径越小,空泡发生表面闭合的时间越早,空泡内部空化效应越强.

In order to research the effects of operating pressure on the projectile＇ s water-entry flow, numerical simulation for process of the high-speed water-entry induced by the cylinder body with a cone head was performed in the way of volume of fluid （VOF） model. Results of the velocity, depth and cavity shape of projectile were achieved and contrasted with the theoretical results obtained by Newton＇ s second law of motion and the literature to verify the correctness of the numerical simulation method. Based on the method, processes with a series of operating pressure were analyzed. Results show that the effects of operating pressure on the phenomena, such as the spatter above the free liquid surface, the cavity surface closure time and the cavitation inside the cavity are great. With the operating pressure being higher, the cavity diameter near the free surface becomes smaller; the cavitation inside is more marked; the time for surface closure happens earlier.