Investigation of free-field underwater explosion with Eulerian finite element method
Investigation of free-field underwater explosion with Eulerian finite element method
复制标题
欧拉有限元法研究水下自由场爆炸
DOI：
10.1016/j.oceaneng.2018.08.001
复制
发表时间：
2018
影响因子：
5
通讯作者：
Wang Shiping
中科院分区：
文献类型：
--
作者：
Liu Yunlong;Zhang A-Man;Tian Zhaoli;Wang Shiping
本文对自由场中的水下爆炸进行了数值研究。利用流体体积法（VOF）捕捉多相界面，建立了水下爆炸问题的欧拉有限元方法。对MUSCL算法进行改进以保持其在轴对称模型中的保守性，并采用二阶早期近似（ETA2）处理计算区域的无反射边界条件。通过与实验结果的比较，验证了数值模型在激波和气泡振荡模拟中的有效性。利用该数值模型，对两种不同初始深度的水下爆炸情况进行了数值模拟，分析了近场压力特性。近场气泡脉动载荷在气泡周围表现出显著的不对称性，这归因于气泡上方和下方的2个高压区域。通过比较不同浮力参数下气泡的演化过程，发现浮力参数的增大可以延缓气泡的穿透，延长气泡的溃灭时间。
Underwater explosion in free field is investigated in this paper numerically. With the multiphase interface captured by the Volume of Fluid (VOF) method, the Eulerian finite element method (EFEM) for underwater explosion is established. The MUSCL algorithm to advect the element centered variables is modified to maintain its conservativeness in the axisymmetric model, and the second order Early Time Approximation (ETA2) is adopted to deal with the non-reflecting boundary condition of the computational domain. By comparing with the experiment results, the numerical model is proved in both shockwave and bubble oscillation simulation. With the numerical model, 2 underwater explosion cases with different initial depths are simulated and the near-field pressure characteristics are analyzed. The near-field bubble pulsation load exhibits noteworthy asymmetry around the bubble, which is attributed to the 2 high pressure regions above and beneath the bubble, respectively. By comparing the evolution of bubbles with different buoyancy parameters, it is found that the increase of the buoyancy parameter can delay the penetration and extend the collapse of the bubble.