侧倾底凹结构对火炮弹丸阻力的影响

Research on Shrinkage Shape of Base Cavity Upon Aerodynamic Drag of Projectile

建立了火炮底凹弹丸的数值计算模型,基于Navier-Stokes方程对底凹弹的超声速绕流流场进行了求解,得到了弹丸的流场参数与阻力系数,探讨了不同底凹侧壁倾斜角度对底凹结构减阻性能的影响。研究发现:就提高弹丸底压以减小其气动阻力而言,带有“收缩角”的底凹结构优于传统的圆柱状底凹结构;底凹结构的“收缩角”存在最优值。

Focuses on the drag reducing efficiency of the base cavity,the projectile with the base cavity was investigated numerically.The supersonic flow field of the projectile with base cavity was simulated with the Navier-Stokes(N-S)equations,the flow field parameters and the aerodynamic drag were obtained.The influence of the slope angle upon the base cavity upper wall on the drag reducing efficiency of the base cavity was discussed.The numerical results show that,compared with the traditional cylinder base cavity shape,the projectile with a base cavity which is shrinkage shape has better drag reducing efficiency.There is optimal slope angle upon upper wall of the base cavity.