Research on the cavitation flow interference and impact loads of successively launched underwater projectiles

Abstract

The cavitation flow can have a great impact on the projectile's water-exit attitude and stability. At present, the research on cavitation flow is mainly focused on the single projectile, while less research has been conducted on the cavitation flow of projectiles successively launched underwater. In this paper, a verification of the flow simulation method and validation of the cavitation model is presented. The multiphase flow associated with cavitation flows, interference characteristics of the cavitation vortex structure, and load characteristics of the projectiles successively launched underwater are studied. The results show that owing to the flow interference, the attitude of the projectile is deflected to the outside. A large-scale cavity shedding phenomenon of the inside cavity occurs under the incoming flow. A large number of small-scale vortex rings appear above the water surface in the projectile that successively exited the water. As the cavitation number of the projectiles launched successively decreases, the turbulent vortex structure is gradually enriched. In addition, both the inside and the outside are subject to extremely high peak collapse loads. Remarkably, the peak pulsating pressure generated by the collapse of the cavity is strongly correlated with the state of the cavity when the head of the projectile touches the water surface.