Impact of centroid position on dynamic behavior of cavitating projectiles in water

The influence of centroid position on the dynamic performance of supercavitating projectiles during high-speed oblique water entry is examined in this study. Numerical simulations are conducted to explore the relationship between varying centroid positions and their effects on supercavitation formation, surface wetting, and projectile speed. It is revealed that shifts in centroid position significantly impact the projectile's dynamic characteristics. Specifically, projectiles with centroids located closer to the tail are found to be more susceptible to tail slap upon water entry, resulting in increased surface wetting due to higher buoyancy and water pressure at the tail. In contrast, projectiles with centroids positioned near the cavitator exhibit slower wetting rates during the initial stages of water entry. The continuous counterclockwise motion of the projectile due to its own inertia, combined with the adhesiveness of water, results in an ongoing increase in the wetted area, leading to an expansion of the local high-pressure region within the wetted zone. Additionally, variations in centroid position are shown to influence both the overall speed of the projectile and the speed of its cavitator, with increased lateral oscillations observed as the centroid shifts toward the tail. Variations in centroid position result in significant differences in the hydrodynamic forces acting on the projectile, directly leading to notable changes in its entry speed within the scope of this study. The lateral displacement at the tail of the projectile is observed to increase significantly as the centroid moves closer to the tail.