Simulation of jet development and cavitation characteristics of a hollow projectile entering water
-
摘要: 空心弹是一种内部中空、流动特性复杂的弹丸, 以其轻便稳定和强大毁伤性能备受关注。在其入水过程中, 高速水射流的产生是影响空心弹入水的关键。因此, 研究空心弹通孔孔径对射流和入水特性的影响具有重要意义。文中建立了不同孔径的空心弹垂直入水仿真模型, 并对比了不同孔径弹丸的孔内压力特性与空泡发展差异。通过研究发现, 孔径比与初始碰撞时刻的孔内压力强度存在关联, 且随着孔径比的增加, 射流的高度与速度均有所降低, 这与空心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, 并对孔径比对空化现象的影响进行了分析, 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: The hollow projectile, characterized by its hollow interior and intricate flow dynamics, has garnered significant attention due to its lightweight, stability, and potent destructive capabilities. In its water entry process, the formation of high-speed water jets is a crucial factor influencing the water entry of hollow projectiles. Consequently, studying the impact of the through-hole aperture of hollow projectiles on jet and water entry characteristics holds considerable importance. This paper establishes a vertical water entry simulation model for hollow projectiles with different aperture diameters. It compares the pressure characteristics within the hole and the variations in vacuole development among projectiles with different aperture diameters. A correlation is identified between the aperture ratio and the intensity of intra-hole pressure at the moment of initial collision. Observations reveal that the projectile's height and velocity decrease with an increase in the aperture ratio, correlating with the pressure gradient phenomenon within the hollow hole. Additionally, the intensity of the pressure gradient diminishes as the aperture ratio increases. The study briefly describes the development of the cavitation phenomenon in hollow projectiles and provides a comparative elaboration on the effect of the aperture ratio on cavitation. Results indicate a gradual decrease in the amount of vapor produced by the projectile with an increase in the aperture ratio, leading to an earlier closing time of the vacuole. This research contributes valuable insights into the complex dynamics of hollow projectile water entry.
-
Key words:
- hollow projectile /
- water entry /
- pressure gradient /
- jet /
- cavitation
-
图 5 空心弹垂直入水实验与仿真相图
Figure 5. Simulation and experimental comparison of phase diagrams of water entry
图 6 空心弹垂直入水射流高度仿真与实验对比
Figure 6. Comparison of water jet height simulation and experiment
图 7 孔径比为0.5时入水时刻液相与压力变化云图
Figure 7. Liquid phase and pressure change at the moment of water entry for pore size d/D = 0.5
图 8 监测点示意图和不同孔径比间测点压力差异
Figure 8. Schematic of the distribution of monitoring points and the difference in pressure at measurement points between different aperture ratios
图 10 射流高度与通孔孔径比大小随时间变化曲线
Figure 10. Relationship between jet height and through-hole aperture ratio size with time
图 11 射流最大速度与孔径比大小随时间变化关系
Figure 11. Maximum jet velocity versus aperture ratio size versus time
图 12 不同孔径比同时刻水相(左)与蒸汽相(右)云图
Figure 12. Cloud diagrams of water phase (left) and vapor phase (right) at the same moment for hollow projectile with different apertures
表 1 弹体参数
Table 1. Projectile parameters
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 
下载: 导出CSV
-
[1] Yushi W. Studying progress on hollow projectile technique in the western countries[J]. Projectile & Rocket Technology, 1996, 9(3): 1-10. [2] Fan H W, Huang Z G, Wang H, et al. Numerical study of high-speed vertical water entry of hollow projectiles with different aperture sizes and velocities[J]. Journal of Applied Fluid Mechanics, 2023, 16(11): 19-34. [3] Wang Z, Feng P, Liu G, et al. Load and motion behaviors of ogive-nosed projectile during high-speed water entry with angle of attack[J]. Ocean Engineering, 2022, 266: 112937. doi: 10.1016/j.oceaneng.2022.112937 [4] Yu Y, Shi Y, Pan G, et al. Effect of asymmetric nose shape on the cavity and mechanics of projectile during high-speed water entry[J]. Ocean engineering, 2022(3): 1-12. [5] 孙钊, 曹伟, 王聪, 等. 表面润湿性对球体入水空泡形态的影响研究[J]. 兵工学报, 2016, 37(4): 670-676. doi: 10.3969/j.issn.1000-1093.2016.04.014Sun Zhao, Cao Wei, Wang Cong, et al. Effect of surface wettability on cavitation of sphere during its water entry[J]. Acta Armamentarii, 2016, 37(4): 670-676. doi: 10.3969/j.issn.1000-1093.2016.04.014 [6] 卢佳兴, 魏英杰, 王聪, 等. 圆柱体并联入水过程空泡演化特性实验研究[J]. 力学学报, 2019, 51(2): 450-461. doi: 10.6052/0459-1879-18-288Lu Jiaxing, Wei Yingjie, Wang Cong, et al. Experimental study on cavity evolution characteristics in the water-entry process of parallel cylinders[J]. Chinese Journal of Theoretical and Appl-ied Mechanics, 2019, 51(2): 450-461. doi: 10.6052/0459-1879-18-288 [7] Shi Y, Xiao P, Zhao H, et al. Experimental research on the influences of head shape and surface p-roperties on the water entry cavity[J]. Journal of Marine Science and Engineering, 2022, 10(10): 1411. doi: 10.3390/jmse10101411 [8] 路中磊, 魏英杰, 王聪, 等. 开放空腔壳体入水扰动流场结构及空泡失稳特征[J]. 物理学报, 2017, 66(6): 167-181. doi: 10.7498/aps.66.064702Lu Zhonglei, Wei Yingjie, Wang Cong, et al. Experimental and numerical investigation on the flow structure and instability of water-entry cavity by a semiclosed cylinder[J]. Acta Physica Sinica, 2017, 66(6): 167-181. doi: 10.7498/aps.66.064702 [9] 侯宇, 黄振贵, 陈志华, 等. 空心圆柱低速垂直入水试验研究[J]. 工程力学, 2019, 36(9): 237-246. doi: 10.6052/j.issn.1000-4750.2018.08.0440Hou Yu, Huang Zhengui, Chen Zhihua, et al. An experimental investigation on the lo-w speed vertical water-entry of hollow cylinders[J]. Engineering Mechanics, 2019, 36(9): 237-246. doi: 10.6052/j.issn.1000-4750.2018.08.0440 [10] Sun T, Shen J, Jiang Q, et al. Dynamics analysis of high-speed water entry of axisymmetric body using fluid-structureacoustic coupling method[J]. Journal of Fluids and Structures, 2022, 111: 103551. doi: 10.1016/j.jfluidstructs.2022.103551 [11] Erfanian M R, Anbarsooz M. Numerical investigation of body and hole effects on the cavitating flow behind a disk cavitator at extremely low cavitation numbers[J]. Applied Mathematical Modelling, 2018, 62(OCT.): 163-80. -
点击查看大图
计量
- 文章访问数: 17
- HTML全文浏览量: 2
- PDF下载量: 5
- 被引次数: 0
