文中以改善火炮底凹弹的飞行阻力为目标,针对火炮弹丸不同底凹结构对减阻效果的影响展开研究。通过基于N-S方程的数值模拟,得到带底凹结构弹丸的绕流流场参数分布以及弹丸的气动阻力,讨论了相同底凹深度、不同形状底凹结构对弹丸流场、减阻效果的影响。研究发现,弹丸底部凹腔产生位于凹腔内的回流流动对底凹结构的减阻效果起决定性作用。研究的三种凹腔形状中,“收缩”形状的底凹结构有最小的气动阻力。

In order to improve aerodynamic drag of projectile with base cavity, drag reducing effect got from projectiles with different base cavity was investigated. Based on Navier-Stokes (N-S) equations, distribution of flow field parameters and aerodynamic drag was obtained by numerical simulation method. The effect of base cavity with same length but different shape on flow field and drag reduction were discussed. The results show that the recirculation region, which is caused by the base cavity and located inside the cavity, plays a pivotal role in reduction of the drag. In the paper, the projectile with a “contraction" shape has the minimum aerodynamic drag.