水下爆炸气泡射流载荷计算的新方法研究

由于存在强冲击、多相界面复杂运动等强非线性效应,目前对于水下爆炸气泡运动的计算方法无法给出较为可信的水射流运动特征及其载荷形式.本文基于多相可压缩流体的five-equation计算模型,引入界面函数和界面密度压缩技术,采用5阶WENO重构与HLLC近似Riemann求解器进行空间离散,时间离散采用3阶TVD Runge-Kutta法.通过上述方法来提高水下爆炸气泡溃灭过程中气-液界面的计算精度,捕捉水射流的产生、发展以及水锤冲击等典型演化过程.计算结果表明,新的计算方法能够对水下近壁面爆炸气泡的溃灭过程进行有效的模拟,初步揭示了水射流直接载荷的特征,为水射流的产生机理及其损伤效应的研究提供技术支撑.

Research on a new method of bubble jet load in underwater explosion

Due to the nonlinear effects such as strong impact and complex motion of a multiphase interface,the current calculation method of bubble motion in underwater explosion cannot provide reliable motion characteristics and load forms of a bubble jet.In this work,the interface function and interface density compression technique are introduced on the base of the five-equation model,and a fifth-order accuracy Weighted Essentially Non-Oscillation (WENO) reconstruction and HLLC approximate Riemann solver are employed to discretize the temporal term,and the third-order TVD Runge-Kutta scheme is used to discretize the temporal term.It is found that this method can improve the accuracy and capture the typical evolution process such as the generation and development of a water jet and the impact of a water hammer.The calculation results show that the model in this paper can effectively simulate the collapse process of underwater explosion bubbles near the wall,and preliminarily reveal the characteristics of water jet load caused by bubble collapse,which can provide support for the research of water jet generation mechanism and damage effect.