The results show that the unstart boundary of supersonic inlets is mainly concerned with Mach number of freestream without considering the variation of angle of attack.

在不考虑攻角变化的条件下，进道不起主要与来流马赫数有。

On condition that the front body shape of the projectile is unchangeable,a formula is obtained for determining the relation between the optimum boattail angle and the supersonic flight region.

在弹丸前体外形和外密度不变的条件下，提出了利用弹丸炮口马赫数和顶点马赫数确定旋转弹丸最佳尾锥角的方法。