Abstract: The effect of water entry angles on the cavitation shape， trajectory characteristics and hydrodynamic characteristics of high-speed projectiles is studied. The VOF(volume of fluid)multiphase flow model， Schnerr and Sauer cavitation model， overlapping grid and 6DOF (degrees of freedom) technology are used to carry out the numerical simulation of the water entry process of a projectile. The results show that the cavitation shape on both sides of the projectile is asymmetric， and the size of the cavitation on the right side is larger than that on the left side. After the projectile enters the water， the smaller the water entry angle， the greater the velocity at the projectile centroid. When the water entry angle is 45°， the fluctuation range of the pitch angle， yaw angle and roll angle is smaller. When the projectile hits the water surface， the drag force and lift force show a peak， but the side force does not show a peak but a slight fluctuation. The water entry angle has little effect on the rolling moment， yawing moment and pitching moment in the stable stage of the projectile flow.

Key words: high speed projectile; numerical simulation; cavitation shape; trajectory characteristics; hydrodynamic characteristics