In this paper, the horizontal water-entry experiments of truncated-ogive projectiles at the velocity range of 100~150 m/s were conducted using a light-gas gun and a high-speed camera to record the whole water-entry process. The characteristics of the velocity attenuation and the drag coefficients of truncated-ogive projectiles were obtained, and the trajectory stability and the characteristics of velocity attenuation for the flat-nosed, the ogive-nosed and the truncated ogive-nosed projectiles were compared and analyzed. The cavity expanding behaviors induced by the truncated ogive-nosed projectile's water entry were studied and a theoretical model of the cavity expansion was established. The relationships between the radial cavity radius, cavity wall velocity and time, penetration distance at fixed locations and fixed times were obtained, and good agreements were found between the experimental observations and the theoretical analysis.
May A. Effect of surface condition of a sphere on its water-entry cavity[J]. Journal of Applied Physics, 1951, 22(10):1219-1222. doi: 10.1063/1.1699831
[2]
May A. Vertical entry of missiles into water[J]. Journal of Applied Physics, 1952, 23(12):1362-1372. doi: 10.1063/1.1702076
[3]
Birkhoff G, Isaacs R. Transient cavities in air-water entry[R]. Navord Report, 1951.
[4]
Lee M, Longoria R G, Wilson D E. Cavity dynamics in high-speed water entry[J]. Physics of Fluids, 1997, 9(3):540-550. doi: 10.1063/1.869472
Zhang Wei, Guo Zitao, Xiao Xinke, et al. Experimental investigations on behaviors of projectile high-speed water entry[J]. Explosion and Shock Waves, 2011, 31(6):579-584. doi: 10.11883/1001-1455(2011)06-0579-06
Guo Zitao, Zhang Wei, Wang Cong. Experimental and theoretical study on the high-speed horizontal water entry behaviors of cylindrical projectiles[J]. Journal of Hydrodynamics, Ser. B, 2012, 24(2):217-225. doi: 10.1016/S1001-6058(11)60237-0
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