关键词: 射弹, 入水, 流体与固体耦合, 空泡面闭合, 空泡深闭合, 阻力系数

Abstract: A fluid-solid coupling calculation model of vertical water-entry of projectile at low subsonic speed is established based on multi-material arbitrary Lagrangian-Eulerian-Lagrangian coupling method. Compressibility effects in fluid mechanics are considered in the proposed model. The multi-medium coupling numerical calculation technology of cavity-fluid-projectile is used to simulate the vertical water entry of projectile. The curves of underwater depth and projectile velocity, and the times of cavity surface closure and cavity deep closure at different velocities of water entry are obtained. The evolutionary process of cavity and the phenomenon during high-speed water entry of projectile are stimulated. The acceleration, stress and strain responses of projectile are obtained, and the influence laws of velocity of water entry on the times of cavity surface closure and cavity deep closure are also obtained. The numerical results show good agreement with the calculated results of empirical formulas. The calculated results show that the proposed numerical method is reliable. Key

Key words: projectile, waterentry, fluid-solidcoupling, cavitysurfaceclosure, cavitydeepclosure, dragcoefficient