Numerical Investigation on the Cavitation Evolution and Trajectory Behaviors of High-Speed Oblique Water Entry of Projectiles

The high-speed water entry is of great significance in the development of the cross-media equipment. In this paper, the high-speed oblique water entry of a conical projectile is numerically investigated with particular emphasis on the local fluid field and trajectory behaviors. The numerical model is based on the Reynolds average Navier-Stokes (RANS) method with the Volume of Fluid (VOF) approach for capturing complicated multiphase flow characteristics. The present method is validated against the published experimental data by simulating a case of high-speed oblique water entry. The highspeed oblique water entry of the conical projectile under different impact velocities are investigated. The comprehensive process of the water entry, including the initial impact, formation, development, contraction, closure and collapse of the open cavity, have been reproduced. The flow evolution process of the high-speed water entry, which involves the cavity shape and the cavitation evolution, is analyzed comprehensively. Furthermore, the variation trends of the impulsive load, the projectile attitude and the trajectory stability are examined. The study is expected to enhance the understanding of the cavitation evolution, and is helpful for the design of the cross-media equipment.