入水角度对高速射弹入水过程的影响

研究入水角度对高速射弹入水过程的空泡形态、弹道特性及流体动力特性的变化规律，计算中使用VOF(volume of fluid)多相流模型，Schnerr and Sauer空化模型，同时结合重叠网格和6DOF(degrees of freedom)技术对射弹的入水过程开展数值模拟.结果表明:射弹两侧空泡形态不对称，与左侧空泡相比，右侧空泡尺寸较大；射弹入水以后，入水角越小，射弹质心处的速度越大；入水角为45°时，俯仰角、偏航角、滚转角的波动范围更小；射弹在撞击水面时，阻力和升力岀现了一个峰值，但侧向力没有岀现峰值，而是一段微小的波动；入水角度对射弹流动稳定阶段的滚转力矩、偏航力矩及俯仰力矩影响非常小.

Influence of Water Entry Angle on High-Speed Projectiles in the Water Entry Process

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.