超空泡射弹尾拍分析与计算

Analysis and calculation for tail-slaps of supercavitating projectiles

对超空泡射弹进行运动学和动力学分析并数学建模,求解耦合非线性微分方程组,得到水下高速超空泡射弹运动特性。数值模拟结果表明,高速超空泡射弹在航行过程中,由于弹体头部和尾部的阻力作用,水平速度随时间迅速衰减。并且射弹的角速度呈周期性往复变化,即尾拍现象。同时由于空泡尺寸的减小导致尾拍幅度逐渐变小。射弹转动惯量越小,角速度变化幅度越平稳,相同时间内尾拍次数减少。发射深度或发射速度越大,尾拍幅度衰减越快。较大的初始角速度也会使射弹角速度很快衰减。

Kinematic and dynamic analysis on underwater high-speed supercavitating projectiles were carried out and a mathematical model was proposed to establish coupling nonlinear differential equations. The equations were resolved to obtain the kinematical characteristics of the projectiles. The numerical simulation results show that the horizontal velocity of the flying projectile decreases rapidly because of the drag forces acting on the tip and the tail of the projectile. The angular velocity of the flying projectile decreases gradually in the fluctuating form, namely, a tail-slap phenomenon. Meanwhile, the vibration extent reduces gradually resulted from the lessening of the cavity dimension. The smaller the projectile＇s moment of inertia is, the less the changing range of the angular velocity and the tail-slap times are. The greater the launching depth or velocity is, the faster the tail slap attenuation is. The higher initial angular velocity can cause the angular velocity of the projectile to attenuate more rapidly.