Study on the mechanism and load characteristics of secondary cavitation near free surface in underwater explosion

Although the cavitation phenomenon in underwater explosion has been researched for more than 100 years, phase transition models based on mass and heat exchange between liquid its vapor phases have only established past decade. In this study, secondary was first captured by a four-equation system. The bulk near free surface induced numerically investigated, three typical cases were investigated to explore their motion mechanisms load characteristics hydrodynamics generation. It found that will occur under condition both initial shock wave intensity distance water bubble are satisfied specific relationship. Producing difficult at relatively deep detonation depth because of weak rarefaction reflected from smaller charges. statistical data small charge indicated duration increases with increase weight but growth trend slows down gradually. However, maximum volume increased linearly an weight. present results can expand currently limited database multiphase fluids provide insight into interactions wave, cavitation, bubble, surface.