近自由面水下爆炸冲击波切断效应研究

近自由面水下爆炸形成的冲击波到达自由面时会反射稀疏波,并伴随着水面的上升、破碎和飞溅等复杂物理现象。文章基于无网格SPH方法建立了近自由面水下爆炸数值模型,开发了计算程序,模拟了冲击波和自由面反射的稀疏波的相互作用过程,分析了切断现象的特性、产生机理以及对冲击波参数的影响。研究发现,爆心正上方且距自由面较近处,稀疏波作用最强;近自由面爆炸冲击波冲量可衰减为无限水域爆炸的1/3左右。文中的研究旨在探索冲击波在自由面处的传播规律,并为近自由面水下爆炸载荷的确定提供参考。

Research on the cutoff effect of shock wave induced by underwater explosion near free surface

The rarefaction wave will be reflected by the free surface when the shock wave induced by un-derwater explosion reaches it,with the surface lifting,breaking up and splashing.The numerical model of the underwater explosion near free surface is established based on the method of SPH,and the programs are developed to simulate the process of interaction between the shock wave and the rarefaction wave.The char-acteristics,forming mechanisms of cutoff effect and its influence on shock wave parameters are analyzed.The results show that the effect of rarefaction wave is stronger when the location is just above the explosive cen-ter and near the free surface.The impulse of the shock wave induced by underwater explosion near free sur-face can reduce to 1/3 of that of explosion in infinite field.This research is to explore the transmitting reg-ularity of shock wave and provide references for the calculation of the load of underwater explosion near free surface.