Influence of Angle of Attack on the Hydrodynamic Characteristics of Supercavitating Projectile in Water-exit Process

doi:10.12382/bgxb.2024.0408

Abstract

Abstract:

The water-exit process of supercaviting projectile often has an angle of attack due to launch perturbation, cross-current, wave, etc., which affects the trajectory of projectile and interferes with the successful water-exit of projectile. A numerical model for the water-exit process of supercaviting projectile with angle of attack is established based on the volume-of-fluid multiphase flow model and the moving computational domain method, and the water-exit processes of projectile at with different angles of attack and velocities are simulated. The calculated results show that a small angle of attack of the projectile has little effect on the cavity morphology in the water movement stage, and the shoulder and tail of projectile are wet with the increase in the angle of attack. A secondary cavity produced by the shoulder wetting may be rewrapped in the tail, and leads to the longer and obvious asymmetric radial distribution of cavity on the inflow side. The cavity has a tendency to expand after the projectile penetrates the water surface. The surface pressure of projectile is high at the beginning of the movement, and the high pressure region decreases rapidly as a cavity is generated, and the local high pressure occurs in the subsequent movement due to local wetting, cavity closure near the water surface, and splash collision with the water surface. The local high pressure occurs mostly on the inflow side, resulting in a higher pressure on that side than on the backflow side. The lateral forces and yaw moments appearing on the projectile cause the trajectory and attitude of the projectile to change and the angle of attack to decrease. The larger the initial angle of attack is, the more obvious its effect on the angle of attack, yaw angle change and trajectory of projectile is. When the projectile is at an angle of attack of 5° and the velocity continues to increase, the effect of velocity on the cavity morphology, the motion trajectory and yaw angle of projectile is weakened.

Key words: supercaviting projectile, water-exit, angle of attack, cavity evolution, hydrodynamics

CLC Number:

TJ297

LI He, WANG Xu, LÜ Xujian. Influence of Angle of Attack on the Hydrodynamic Characteristics of Supercavitating Projectile in Water-exit Process[J]. Acta Armamentarii, 2025, 46(5): 240408-.

Figures/Tables 24

Fig.1 Schematic diagrams of the projectile model, angle of attack and yaw angle

Table 1 Calculational cases

工况	初始攻角/(°)	初始速度/(m·s^-1)
1	0	200
2	1	200
3	3	200
4	5	200
5	5	100
6	5	300

Fig.2 Calculation domain and reference coordinate system settings

Fig.3 Schematic diagram of mesh division

Fig.4 Change of resistance coefficient and velocity with time for different mesh number conditions

Fig.5 Supercaviting projectile modelling in Ref. [18]

Fig.6 Comparison of experimental and simulated cavity morphologies of a projectile exiting water at high velocity

Fig.7 Comparison of experimental and simulated cavity lengths and projectile motion displacements

Fig.8 Cavity evolution and flow field velocity distribution at the initial stage of projectile motion at different angles of attack

Fig.9 Cavity evolution and surface wetting characteristics in water-exit process of projectile at different angles of attack

Fig.10 Cavity profiles of projectile water-exit at different angles of attack

Fig.11 Pressure distribution of projectile in water-exit process at different angles of attack

Fig.12 Distribution of projectile surface monitoring points

Fig.13 Change of pressure at monitoring points on the surface of projectile with time

Fig.14 Velocity distribution of projectile in water-exit process at different angles of attack

Fig.15 Changes of projectile motion parameters with time at different angles of attack

Fig.16 Changes of yaw moment coefficients of projectiles with time at different angles of attack

Fig.17 Schematic diagram of the change in the angle of attack of projectile

Fig.18 Cavity evolution and surface wetting characteristics of projectile in water-exit process at different velocities

Fig.19 Comparison of cavity profiles for projectiles exiting the water at 200m/s and 300m/s

Fig.20 Distribution of pressure and velocity fields for the projectile exiting the water at different velocities

Fig.21 Change of pressure with time at the monitoring point on inflow side of projectile

Fig.22 Changes of projectile motion parameters with time at different velocities

Fig.23 Changes of projectile yaw moment coefficients with time at different velocity

References 22

[1]	姚忠, 王瑞, 祁晓斌, 等. 初始扰动对高速射弹尾拍过程流体动力特性与弹道特性的影响[J]. 兵工学报, 2020, 41(增刊1): 46-53.
	YAO Z, WANG R, QI X B, et al. The influence of initial disturbance on the hydrodynamic and ballistic characteristics of high-speed projectile during tail slapping[J]. Acta Armamentarii, 2020, 41(S1): 46-53. (in Chinese)
[2]	WANG X, QI C, LIU C, et al. Experimental study on the cavity dynamics of a sphere entering flowing water[J]. Physics of Fluids, 2024, 36: 022102.
[3]	ZHANG S, XU H, SUN T Z, et al. Water-exit dynamics of a ventilated underwater vehicle in wave environments with a combination of computational fluid dynamics and machine learning[J]. Physics of Fluids, 2024, 36: 023312.
[4]	ASHRAF I, DORBOLO S. Exit dynamics of a square cylinder[J]. Ocean Engineering, 2024, 297: 117106.
[5]	ASHRAF I, DORBOLO S. Effect of the surface dimples on the exit dynamics of a sphere at a constant velocity[J]. Applied Ocean Research, 2024, 147: 103996.
[6]	YUN H L, LIU Q B, ZENG Z, et al. Experimental study on water-exit of cylinder[J]. Ocean Engineering, 2024, 293: 116585.
[7]	ZHANG Q S, MING F R, LIU X J, et al. Experimental investigation of the dynamic evolution of cavity during the free water-exit of a high-pressure venting vehicle[J]. Physics of Fluids, 2023, 35: 122118.
[8]	ZHAO Q K, CHEN T, XIAO W, et al. Research on the characteristics of cavitation flow and pressure load during vertical water exit of different head-shaped vehicles[J]. Ocean Engineering, 2022, 265: 112663.
[9]	TAKAMURE K, UCHIYAMA T. Calculation model for water mass entrained by the water exit of a particle using two projected images captured from orthogonal directions[J]. Ocean Engineering, 2022, 266: 112848.
[10]	NGUYEN V T, PHAN T H, DUY T N, et al. Unsteady cavitation around submerged and water-exit projectiles under the effect of the free surface: a numerical study[J]. Ocean Engineering, 2022, 263: 112368.
[11]	ZHANG X Y, LYU X J, FAN X D. Numerical study on the vertical water exit of a cylinder with cavity[J]. China Ocean Engineering, 2022, 36(5): 734-742.
[12]	GUO Z Q, ZHAO Y, ZHANG X Y, et al. On the cavity flow of a cylinder exiting water obliquely[J]. Ocean Engineering, 2023, 281: 114683.
[13]	高山, 施瑶, 潘光. 航行体出水过程空化结构演变与溃灭载荷特性研究[J]. 振动与冲击, 2024, 43(2): 306-314.
	GAO S, SHI Y, PAN G. Evolution of cavitation structure and collapse load characteristics during underwater vehicle exiting-water process[J]. Journal of Vibration and Shock, 2024, 43(2): 306-314. (in Chinese)
[14]	CHEN Y, LI J, GONG Z X, et al. LES investigation on cavitating flow structures and loads of water-exiting submerged vehicles using a uniform filter of octree-based grids[J]. Ocean Engineering, 2021, 225: 108811.
[15]	ZHANG G Y, LIANG G Q, YANG X, et al. Numerical investigations on water entry and/or exit problems using a multi-resolution Delta-plus-SPH model with TIC[J]. Ocean Engineering, 2024, 292: 116560.
[16]	SUN T Z, ZHANG J Y, WEI H P, et al. Experimental investigation of the influence of floating ices constraint on the cavity dynamics of an axisymmetric body during the water exit process[J]. Ocean Engineering, 2022, 244: 110383.
[17]	WANG H, HUANG Z G, CAI X W, et al. Analysis of the water-exit cavity evolution and motion characteristics of an underwater vehicle under the effect of floating ice[J]. Ocean Engineering, 2024, 300: 117374.
[18]	SHI H H, ZHOU D H, LU L W, et al. On the water exit of supercavitating projectiles with different head shapes[J]. Shock Waves, 2021, 31: 597-607.
[19]	LI J M, ZHENG J, JING S B. Influence of cavitation state and launch angle on water-exit process of vehicle based on moving domain method[J]. Journal of Physics: Conference Series, 2023, 2472(1): 012028.
[20]	卢佳兴, 王聪, 魏英杰, 等. 回转体齐射出水过程空泡演化规律与弹道特性实验研究[J]. 兵工学报, 2019, 40(6): 1226-1234. doi: 10.3969/j.issn.1000-1093.2019.06.013
	LU J X, WANG C, WEI Y J, et al. Experimental research on cavity evolution pattern and trajectory characteristics in the water-exit process of salvoed revolving bodies[J]. Acta Armamentarii, 2019, 40(6): 1226-1234. (in Chinese)
[21]	WANG Q, CAO W, ZHANG T Y, et al. Research on cavity collapse characteristics during high-speed water-exit of the supercavitating projectile[J]. Physics of Fluids, 2023, 35(7): 073307.
[22]	陈伟善. 高速超空泡射弹尾拍运动特性数值研究[D]. 南京: 南京理工大学, 2020.
	CHEN W S. Numerical study on the motion characteristics of the tail-slap of the high-speed supercavitating projectile[D]. Nanjing: Nanjing University of Science & Technology, 2020.