考虑空泡脉动的锥形体入水全过程数值模拟

Numerical Simulation of Water Entry Process of Cones Considering Cavitation Pulsation

摘要:

航行体入水作为经典的流体力学问题，长期受到学术界广泛关注。然而，现有研究多集中于航行体入水后的首次砰击压力峰值与航行体运动轨迹分析，对空泡闭合阶段的流固耦合机制鲜少涉及。值得注意的是，当航行体完全浸没后，空泡闭合引发的压力震荡现象将显著改变其运动特性，该机制尚未得到系统研究。现有研究表明，流体介质的可压缩性对于模拟空泡闭合后的运动响应具有重要的影响。采用可压缩轴对称多相有限体积法（Finite Volume Method，FVM）研究锥形体入水问题，着重揭示空泡闭合后的锥形体动力学响应。结果表明：本文建立的可压缩轴对称多相 FVM 模型能很好地模拟此类入水问题，可精确复现航行体入水、空泡闭合、射流和压力振荡等过程。同时，阐释了导致航行体加速度振荡的原因。

Abstract:

Water entry of a vehicle，as a classical fluid mechanics problem，has long attracted extensive academic attention. However，existing research predominantly focuses on analyzing initial impact pressure peak and the trajectory during water entry，and rarely involves the fluid-structure interaction mechanisms during cavity closure stages. It is worth noting that when the vehicle is completely submerged，pressure oscillation induced by cavity closure will significantly alter the kinematic behavior of the vehicle. This mechanism has not yet been systematically studied. Current studies indicate that fluid compressibility has an important influence on simulation of the kinematic response after cavity closure. In this work，the compressible axisymmetric multiphase FVM model is used to study the water entry problem of a cone，especially the kinematic response of the cone after the cavity closure. The results show that the compressible axisymmetric multiphase FVM model can simulate this kind of water entry problem well and accurately reproduce key physical processes，such as vehicle water entry，cavity closure，jet and pressure oscillations. At the same time，the causes of vehicle acceleration oscillation are analyzed and explained.