近边界面的水下爆炸冲击波传播特性及气穴效应

炸药在水下起爆后,产生的冲击波在传播过程中将主要遇到两种边界面:自由水面和结构面边界,而这些边界面的存在将显著影响冲击波的传播特性。考虑冲击波与自由面及结构面的动态耦合相互作用,基于Lagrangian-Eulerian耦合算法,建立了近边界面水下爆炸全耦合模型,通过与已有文献的研究成果及经验公式进行对比,验证了数值模型的可靠性;对自由场、近自由面、近背空气结构面及近背水结构面水下爆炸的冲击波传播特性进行了系统的研究,探讨了不同边界面条件下的水下爆炸冲击波传播特性机制。研究表明,近边界面对水下爆炸冲击波传播特性具有重要的影响,近自由面和近背空气结构面水下爆炸均产生了气穴效应。

The influence of boundaries on the shock wave propagation characteristics and cavitation effects of underwater explosion

After the underwater detonation of an explosive, the shock wave may approach two main types of boundaries: the free water surface, and the fluid-structure interface. The presence of these boundaries will significantly affect the wave propagation phenomena. A coupling numerical approach based on the La-grangian and Eulerian method is used to simulate the water-air interfaces and shock wave-structure interaction. A numerical model of free-field explosion in water is established, and the results have been com-pared with the published empirical formulas to illustrate the results of the numerical solutions. The shock wave propagation characteristics from explosions in water near different boundaries are simulated and com-pared. The unsteady cavitation just near the free surface and the structure is described and captured. The water-air and water-structure interaction effects are examined. The results show that the free surface and structure boundary have significant influence on the shock wave propagation. The presence of these boundar-ies will lead to bulk cavitation near the structure or free surface.