Experimental and numerical study of the water entry of projectiles at high oblique entry speed

The water entry of cylindrical projectiles at high oblique speed has been investigated experimentally and numerically. Projectiles with three types of noses and different lengths are tested. The projectiles are lunched at different angles, and the development of supercavities are recorded using high-speed camera. During the water entry, deflections occur due to the deviation of the initial velocity and/or the hydrodynamic impact force. The evolution of the supercavities of projectile without deviation is observed. It is found that the collapse of cavity and the generation of new cavity occur alternatively. The motion and the evolution of supercavities at the initial stage of the water entry are simulated through computational fluid dynamics, the typical pressure distributions have been analysed. The drag coefficients are dominated by the nose shape. •The cavity profiles depends on the nose shape of the projectile, ogival nose induces smaller cavity.•The collapse of old cavity and generation of new cavity occur alternatively during the high speed water entry.•The pressure distribution and the drag coefficient are dominated by the nose shape, rather than mass and velocity.