低亚声速射弹垂直入水的流体与固体耦合数值计算研究

基于多物质的任意拉格朗日-欧拉-拉格朗日流体与固体耦合算法，考虑水的可压缩性，建立了低亚声速射弹垂直入水的流体与固体耦合计算模型。对低亚声速射弹入水时空泡、流场与弹道间的多介质耦合问题进行了数值计算，得到了不同入水条件下入水深度、速度变化曲线和空泡面闭合、空泡深闭合时间。模拟了高速射弹入水后的空泡演化过程，得到了射弹初始入水速度对空泡面、空泡深闭合时间的影响规律以及射弹加速度、应力、应变响应。将阻力系数数值计算结果与经验公式计算结果进行了比较，二者吻合良好，表明该数值计算方法是可行的。

Fluid-solid Coupling Numerical Simulation on Vertical Water Entry of Projectile at Low Subsonic Speed

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.