Simulation of Water Entry Jet and Cavitation Characteristics of Hollow Projectiles
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摘要: 空心弹入水过程中, 高速水射流的产生是影响其入水的关键。为深入研究空心弹通孔孔径对射流和入水特性的影响, 文中建立了不同孔径的空心弹垂直入水仿真模型, 并对比分析了不同孔径弹丸的孔内压力特性与空泡发展差异。分析结果表明, 孔径比与初始碰撞时刻的孔内压力强度有关, 且随着孔径比的增加, 射流的高度与速度均有所降低, 这与通孔内的压力梯度现象有关; 同时, 压力梯度的强度随着孔径比的增加而降低。文中还对空心弹空化现象发展进行了简要描述, 分析了孔径比对空化现象的影响, 可知随着孔径比的增大, 弹体产生的蒸汽量逐渐减少, 空泡闭合时间提前。Abstract: In the water entry process of hollow projectiles, the formation of high-speed water jets is a crucial factor influencing their water entry. In order to study the influence of the through-hole aperture of hollow projectiles on jet and water entry characteristics, a vertical water entry simulation model for hollow projectiles with different apertures was established, and the intra-hole pressure characteristics and the difference in cavity development among projectiles with different apertures were compared. The results show that the aperture ratio is related to the intensity of intra-hole pressure at the moment of initial collision. The height and velocity of the jet decrease with an increase in the aperture ratio, which is related to the intra-hole pressure gradient. Additionally, the intensity of the pressure gradient diminishes as the aperture ratio increases. This study briefly describes the development of the cavitation phenomenon in hollow projectiles and analyzes the influence of the aperture ratio on the cavitation phenomenon. The results indicate that as the aperture ratio increases, the amount of vapor produced by the projectile decreases, leading to an earlier closing of the cavity.
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Key words:
- hollow projectile /
- water entry /
- pressure gradient /
- jet /
- cavitation
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表 1 弹体参数
Table 1. Parameters of the projectile
模型 L/mm D/mm d/mm M/kg a 400 40 20 4.07 b 24 3.47 c 28 2.77 d 32 1.95 -
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