超音速条件下船尾形弹尾减阻机理研究

Research on Drag Reduction Mechanism of Projectile Boattail Under Supersonic Condition

采用计算流体力学方法对超音速条件下不同马赫数的船尾外形模型进行数值分析。对比弹箭船尾部流场、船尾表面以及弹底的压力系数分布结果表明,弹箭尾阻随尾锥角增加线性增大;弹箭底阻受弹底面积和尾锥角影响,并且随着收缩比增大线性增大;弹箭整体阻力系数与底阻和尾阻有关,尾部长度一定时,存在使阻力系数最小的尾锥角,其大小与弹箭飞行速度有关。

The numerical analysis was carried out under different Mach Numbers by using computational fluid dynamics(CFD)method.By comparing the flow field at the tail of the projectile,the distribution of the pressure coefficient on the stern surface and the bottom of the projectile,The results show that the boattail resistance of the projectile was affected by the boattail angle and increases linearly with the increase of boattail angle;the bottom resistance of the projectile was affected by the area of the projectile base and boattail angle,and increases linearly with the shrinkage ratio;The overall resistance coefficient is affected by the bottom resistance and the tail resistance.When the boattail length is constant,there is a boattail angle to minimize the drag coefficient,and the size of boattail angle is related to the speed of the projectile.