非等强度多道冲击波作用下空泡溃灭机制分析

航空航天、生物医学等领域均存在冲击波与空泡作用问题，冲击波尤其是多道冲击波作用下空泡溃灭包含着复杂的多相瞬变行为与物理现象。基于自主搭建的可压缩多相流并行数值平台，对液体中单一/多道冲击波与空泡的作用过程进行了数值模拟。通过对冲击波作用下空泡内波系性质，以及多道冲击波与空泡作用后的系列反射波系在液体中的相互作用过程进行详细解析，分析了不同冲击波作用下空泡的形变演化过程，探究了空泡的溃灭机制与特性。研究发现，相较于单一冲击波的作用，多道冲击波作用下空泡内部及周围液体流场中的波系结构更为复杂，然而无论是单一冲击波或是多道冲击波工况，其最终诱发的空泡溃灭形态均十分相似。而且，当空泡发生溃灭前所受到多道冲击波的总强度与单一冲击波强度相等时，空泡的溃灭波强度也十分相近，为多道冲击波与空泡作用效果的定量化评估提供了理论基础和依据。

Mechanism of cavity collapse induced by multiple shock waves of different strengths

The cavity collapse induced by the shock wave, especially multiple shock waves, is a compressible multiphase problem which contains transient fluid dynamics and complex physical phenomena. As this problem widely exists in many application fields, for example the spacecraft fuel injection and the extracorporeal shock wave therapy processes, it is necessary to carry out detailed analyses on it. In this study, the interaction process between single/multiple shock waves and the cavity in liquid is numerically simulated based on our in-house compressible multiphase parallel platform. The procedures of wave evolution and cavity collapse under different initial shock wave configurations are investigated in detail. It is found that, comparing with the configuration of one single shock wave, the wave system structures in both the liquid flow field and the cavity are more complex under the configuration of multiple shock waves. However, the cavity collapse processes are quite similar under all these conditions. It is also found that when the total intensity of multiple shock waves, which have interacted with the cavity before the cavity collapsing, is equal to that of the single shock wave, the collapse wave intensities would be quite equivalent. This phenomenon provides a roughly quantified evaluation of the effect of multiple shock waves interacting with the cavity.