Research on the flow field and trajectory characteristics of high-speed projectile entry water in waves.

This article focuses on the numerical investigation of the effects of ocean waves on the high-speed oblique water entry of finned supercavitating projectiles, which are ammunition designed for high-velocity underwater motion using the supercavitation principle. Using a computational fluid dynamics (CFD) model based on Reynolds-averaged Navier–Stokes (RANS) equations combined with turbulence, multiphase flow, and cavitation models, the study analyzes how wave phase and inclination alter cavitation formation, hydrodynamic forces, and projectile trajectory stability during water entry at speeds around 1220 m/s. Results indicate that variations in wave inclination change the actual water-entry angle, significantly affecting cavity asymmetry near the free surface, impact forces on the projectile—especially on the tail fins—and the amplitude and frequency of tail slap motions, which influence post-entry stability. However, when the actual water-entry angles are similar, the forces and trajectories remain consistent across different wave conditions, suggesting that wave slope has minimal effect on high-speed entry trajectories beyond the free surface region.