底凹弹侧壁斜孔减小底阻分析

Analysis of Base Drag Reduced by Side Holes in the Projectile with Base Cavity

超音速条件下，弹丸的空气阻力包括波阻、底阻和摩阻，其中底阻约占总阻的２０％～４０％，减小弹丸飞行中的空气阻力对改善其弹道性能是十分有利的。该文提出了一个底凹弹在超声速条件下侧壁开孔减小底阻的数学力学模型。该模型经计算结果表明，与以往的实验结果相吻合，可作为探索底凹弹侧壁开孔减阻效应和工程计算的基础。文末对侧壁斜孔的不同参数对底阻的影响作了计算分析和讨论。

The flight drag of a projectile includes wave,base,friction drag under supersonic speed, and the base drag is about 20￣40 percent in total drag. To reduce the flight drag of a projectile is very useful to its trajectory. A mechanical model about a projectile with base cavity and side holes,which could reduce the base drag in supersonic speed,has been put forward in this paper. Since the comparison between calculations and experimental results is in good agreement,the model could be taken as a basis for studying the drag reducing effect of side holes and to make an engineering prediction. In the end, the influence of different parameters of side holes on base drag has been discussed.