两种典型尾翼形状对无伞末敏弹气动特性的影响

Effect of Two-tipical Wing Shapes on Aerodynamic Characteristics of Non-parachute Terminal-sensitive Projectile

为研究尾翼形状对双翼无伞末敏弹减速导旋性能的影响,分别对平板尾翼和S-C形尾翼结构末敏弹的气动特性进行研究。基于计算流体力学方法,获得了末敏弹气动外形的流场特性、表面压力分布和阻力系数、升力系数和转动力矩系数随攻角变化的规律。通过自由飞行试验对平板尾翼和S-C尾翼末敏弹进行了动态气动特性研究。数值计算结果显示,平板尾翼和S-C尾翼模型阻力系数在6～9间,其增阻效果明显;两模型升力系数均呈负线性变化,尾翼形状对升力系数影响较小;尾翼形状对转动力矩系数影响明显,平板尾翼几无转动力矩产生,S-C尾翼转动力矩相对较大并随攻角增加而减小。自由飞行试验表明,S-C尾翼结构自由飞行状态下增阻效果好于平板尾翼,并可使弹体获得转动力矩而维持稳定转速,能够实现稳态扫描运动。平板尾翼末敏弹自由飞行稳定性差。

To get the effect of wing shapes on the decelerating and spinning performances of double- wing non-parachute terminal-sensitive projectiles, the aerodynamic characteristics of terminal- sensitive projectiles with fiat wings and S-C wings are studied here. Based on the computational fluid dynamics method, the flow field characteristics of aerodynamic shapes of two-wing terminal-sensitive projectiles and their surface pressure distribution are obtained, and the change laws of drag coefficients, lift coefficients and torque moment coefficients versus attack angles are calculated. The dynamic aerodynamic characteristics of terminal-sensitive projectiles with two-shape wings are researched by free flight tests. Numerical results show that, when the drag coefficients are 6 ~ 9, these two-tipical wing shapes have the obvious deceleration effects. The lift coefficients of two models are negative linear versus attack angles, and wing shapes have weak effects on lift coefficient but significant effects on torque coefficients. Flat wings bring no torque moments, and the torque momentis big for the S-C wings and it decreases with the increase of the attack angle. Test results show that, under the free flight condition, the S-C wing model has the better deceleration effect than the flat wing model and it can maintain stable spin velocity and realize the steady scanning motion. The flat wing model shows worse free flight stability.