Jet development and impact load of underwater explosion bubble on solid wall
Jet development and impact load of underwater explosion bubble on solid wall
复制标题
水下爆炸气泡对固体壁的射流发展及冲击载荷
DOI：
10.1016/j.apor.2019.102013
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发表时间：
2020-02-01
影响因子：
4.3
通讯作者：
Chen, Liang
中科院分区：
文献类型：
--
作者：
Tian, Zhao-Li;Liu, Yun-Long;Chen, Liang
水下爆炸的毁伤效应一直是船舶力学中的一个重要问题。由于结构的不连续性和显著的非线性变形，气泡演化和射流冲击载荷是船舶结构抗冲击设计中最困难的部分之一。本文采用欧拉有限元法，结合流体体积法和压力平衡技术求解多介质流动，对水平固壁附近的激波和非球形气泡的演化过程进行了连续模拟。在圆柱坐标系下建立了数值模型，并通过与电火花气泡实验结果的比较进行了验证。在此基础上，对水下爆炸冲击波的传播和气泡的演化进行了数值模拟，研究了水下爆炸冲击载荷的特性。此外，还分析了墙的位置（上下）和与墙的距离的影响。结果表明，射流冲击载荷的特性比冲击波的特性复杂得多。在下壁附近，浮力和Bjerknes力以相反的影响竞争主导气泡运动。相反，它们相互增强作用，形成向上壁的液体射流。压力峰值、冲击范围和持续时间非线性地依赖于情况参数的组合，而不是单调地依赖于单个参数。在适当的参数组合范围内，射流冲击载荷可以达到最大值，并且由于压力峰值相当，持续时间更长，因此比冲击波更具破坏性。
The damage effects of an underwater explosion have always been a crucial problem in the ship mechanics. Notably, the bubble evolution and the jet impact load are one of the most difficult parts in the shock-resistance design of ship structures due to the discontinuities and significant nonlinear deformation. In this paper, the Eulerian finite-element method is introduced to continuously simulate the shock wave and non-spherical bubble evolution stages near a horizontal solid wall with the volume of fluid method and pressure balance technique used to resolve the multi-medium flow. The numerical model is established in a cylindrical coordinate system and validated by comparing the results with a spark-generated bubble experiment. After that, based on the present model, the shock wave propagation and the bubble evolution are simulated to study the characteristics of the impact loads of an underwater explosion. Besides, the influences of the wall location (upside or downside) and the stand-off distance from the wall are also analyzed. The results show that the features of the jet impact load are much more complicated than those of the shock wave. Nearby a downside wall, the buoyancy and Bjerknes force compete to dominate the bubble motion with opposite influences. By contrast, They enhance the effect of each other to develop a liquid jet towards the upside wall. The pressure peak, impact range, and duration time nonlinearly depend on the combination of the case parameters and are not monotonic to a single one. Within a proper range of the parameter combination, the jet impact load can reach its maximum and be more destructive than the shock wave because of a comparable pressure peak and a much longer duration.