高速弹体水平入水产生冲击波特性

The underwater shock wave characteristics caused by high speed horizontal water entry projectiles

高速弹体入水产生的冲击波对弹体的水下运行与毁伤性能有着至关重要的作用.为得到高速弹体入水产生的冲击波及其传播特性,利用一级轻气炮高速发射平头和球形两种不同弹体水平入水,通过以不同方式分布于水下的压力传感器测量因此而形成冲击波峰值压力衰减特性.实验结果表明:初始冲击波峰值压力随着距离和角度以不同的方式衰减;在波的传播方向上,其满足指数衰减的形式,压力介于距离的倒数与距离平方的倒数之间的曲线之间.在球形波阵面上则以正弦曲线的形式衰减,这种沿距离和角度衰减的冲击波峰值不受弹体的初始速度的影响.

The shock waves caused by the high-speed water entry projectiles have significant effects on the trajectory and damage performance of under-water projectiles. In this paper, the light-gas gun based system was exploited to accelerate the flat and spherical projectiles into a water-filled vessel at different initial velocities horizontally. The impact induced underwater shock waves caused by the two typical projectiles were investigated on the characteristics of propagation and attenuation. The pressure history captured by the transducers installed with different distributions in water column was analyzed in terms of the attenuate characteristics according to the distances and angles. The results indicate that the peak pressure of initial shock waves undergoes an exponential decay and the pressure among the curves 1/x and 1/x2 according to the distance. The decay characteristics of pressure on the spherical surface comply with the sine curve. The attenuation experienced by the pressure for different experimental conditions are independent with initial velocity of projectiles.