大长径比低旋尾翼稳定火箭弹最佳转速的确定

Determination of Angular Velocity of the Slow-rotation of Slender Rockets with the Fins

为了提高射击精度和密集度,对于尾翼稳定火箭弹,一般都采用低速旋转的方式消除推力偏心、质量偏心和气动偏心等的影响。但低旋时火箭弹转速应避免共振转速,即保证出炮口后弹轴章动角迅速衰减;大长径比尾翼火箭弹在飞行时自身还会产生弹性随机振动,转速设计还应避开火箭弹的固有振动频率,以防止发生结构共振。文中采用ANSYS有限元软件计算火箭弹的固有振动频率和动力响应特性,并依据这些计算结果给出最佳转速的确定方法。

For rockets with fins stable, we usually take low-rotation to vanish the thrust offset, eccentric mass and aerodynamic offset for improving shooting precision and denseness. But while lowly rotating, rockets should avoid the oscillating angular velocity of them, or say, rockets' nutation angular attenuates immediately after they are shooted. Slender rockets with fins will vibrate at random during flying, so when the angular velocity of them is designed, the natural frequency should be also avoided to prevent themselves from oscillating in step structurally. In the paper ANSYS is used to calculate the natural frequency of the rocket and vibrating response, from which the best scheme of the angular velocity of the slender rocket will be determinated.