常見例句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. 在彈丸前體外形和外界大氣密度不變的條件下，提出了利用彈丸炮口馬赫數(shù)和頂點馬赫數(shù)確定旋轉彈丸最佳尾錐角的方法。boattail 船形尾部 返回 boattailed