Abstract
In this article, the horizontal water-entry of flat-nose projectiles of two different lengths at impact velocities of 400 m/s-600 m/s is studied experimentally and theoretically. Based on the solution of the Rayleigh-Besant problem, a set of projectile dynamic equations are derived and a cavity model is built to describe the projectile’s water entry dynamics. A parameter in the cavity model is determined by employing the principle of energy conservation. The results indicate that the flat-nose projectiles enjoy a good stability of trajectory, the drag coefficient and the velocity decay coefficient are dependent on the cavitation number, and increase along the penetration distance but with a relatively small variation. The maximum cavity radius decreases monotonically with the penetration distance. Projectiles with the same nose shapes at different initial velocities have a basically consistent cavity dimension before the deep pinching off phenomenon occurs. Good agreements are observed between results obtained by the analytical model and the experimental results.
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Biography: GUO Zi-tao (1979-), Male, Ph. D. Candidate
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Guo, Zt., Zhang, W. & Wang, C. Experimental and Theoretical Study on the High-Speed Horizontal Water Entry Behaviors of Cylindrical Projectiles. J Hydrodyn 24, 217–225 (2012). https://doi.org/10.1016/S1001-6058(11)60237-0
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DOI: https://doi.org/10.1016/S1001-6058(11)60237-0