Numerical analysis of cavitation and impact load characteristics of supercavitating vehicle entering water at high speed

超空泡航行体高速入水空泡与载荷特性数值分析

¹ School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an 710072, China
² Key Laboratory of Unmanned Underwater Vehicle, Northwestern Polytechnical University, Xi’an 710072, China

Received: 23 September 2021

Abstract

In order to obtain the influence of water entry angle and speed on the cavitation and impact load characteristics of supercavitating vehicle, a high-speed water entry numerical model of supercavitating vehicle based on VOF model is established, and the accuracy of the model is verified by relative experiments. Through simulation, the cavitation evolution process, cavitation size, impact load change and surface pressure distribution of supercavitating vehicle entering water at different angles and velocities are obtained and compared. The results show that with the increase of water entry velocity, the depth of cavitation closing position increases, the cavitation size increases, the peak value of axial load increases and the surface pressure of vehicle increases; With the increase of water entry angle, the bubble closing time remains unchanged, the bubble size decreases, the axial load peak increases, and the asymmetry of pressure distribution decreases. The pressure on the upstream surface of the cavitator increases along the radius to the center of the circle, but the asymmetry decreases when it enters the water obliquely.

摘要

超空泡航行体高速入水过程中的空泡特性与载荷特性对其航行高速性与安全性十分重要, 为获得入水角度与速度对超空泡航行体空泡和载荷特性的影响, 建立了基于VOF模型的超空泡航行体高速入水数值模型, 并通过实验验证了模型的准确性。通过仿真对比了不同角度和速度下超空泡航行体入水的空泡演变过程、空泡尺寸、冲击载荷变化、航行体表面压力分布, 结果表明: 随着入水速度增大, 空泡闭合位置的深度增大, 空泡尺寸增大, 轴向载荷峰值增大, 航行体表面压力增大; 随着入水角度增大, 空泡闭合时间不变, 空泡尺寸减小, 轴向载荷峰值增大, 压力分布不对称性减弱。空化器迎流面压力沿着半径向圆心方向增大, 但斜入水时的不对称现象减弱。