基于动网格的穿甲弹脱壳过程仿真研究

Simulation research on shelling process of armor-piercing projectile based on dynamic mesh

电磁发射的脱壳穿甲弹出炮口初速高达6Ma以上,在气动力作用下弹托会自动脱离弹体,脱壳过程稳定与否直接影响后续弹体的飞行。为了分析脱壳过程流场特性与弹托的运动姿态,利用动网格技术建立了流体力学与6DOF刚体动力学耦合的数值仿真模型,分析了脱壳过程中激波与弹体弹托相互作用以及弹托分离的规律。结果表明:首先弹托迎风槽处高压与其外表面凸起处的斜激波为弹托提供了翻转力矩,弹托与弹体之间产生的激波遇到壁面发生反射叠加耦合效应,导致表面压力增大,弹托受到径向力,与弹体逐渐分离。随着弹托轴向与径向位移增加,弹体与弹托气流耦合作用降低,各自自由飞行。同时激波耦合效应对弹体表面产生了额外压力,引起气动参数剧烈变化,对脱壳过程弹体的飞行产生了干扰。

The velocity of the electromagnetically launched shelling armor-piercing projectile is as high as 6Ma,and under the action of aerodynamic force,the projectile sabot will automatically separate from the projectile,and the stability of the shelling process directly affects the subsequent flight of the projectile.In order to describe the flow field characteristics and the the movement posture of the sabot of armor-piercing projectile during the shelling process,a numerical simulation model for coupling fluid mechanics and 6DOF rigid body dynamics was established by using dynamic mesh technology,and the law of the interaction between the shock wave and the projectile sabot and the separation of the sabot during the shelling process were analyzed.The results show that the high pressure at the windward groove of the sabot and the oblique shock waves at the convex part of its outer surface provide the flipping torque.The shock wave generated between the sabot and the projectile encounters the wall to produce a reflection superimposed coupling effect,which increases the surface pressure and provides radial force for the separation of the sabot,and the sabot and the projectile are gradually separated.As the axial and radial displacement of the sabot increases,the coupling effect of the airflow between the projectile and the sabot decreases,and they each do free flight.At the same time,the shock wave coupling effect also produces extra pressure on the surface of the projectile,causing drastic changes in aerodynamic parameters,and disturbing the flight of the projectile during the shelling process.