高速旋转条件下的弹丸气动特性研究

为了能定量揭示弹丸旋转对马格努斯效应的影响,数值模拟了旋转弹丸在不同来流与转速条件下的流场分布,分析了马格努斯现象的产生机理,以及通过弹体表面压力分布分析了旋转对各气动力的影响,得知旋转对升阻力影响很小,可忽略不计; 得到了攻角、马赫数以及转速变化时马格努斯效应对弹丸表面压力分布的影响。结果表明,弹尾部是影响马格努斯效应的主要部位,小攻角情况下马格努斯力及力矩系数随攻角及转速呈线性变化,而随马赫数增大,旋转效应对弹丸影响越来越小。提出并验证了适用于小攻角、超声速情况下马格努斯力及力矩系数的经验公式,可为相关旋转弹丸的改进与设计提供指导。

Aerodynamic Characteristics of A Projectile With High Spinning Speeds

In order to quantitatively reveal the influence of spinning projectile on Magnus effect,the flow-field distribution around the spinning projectile were numerically simulated based on computational fluid dynamics.The generating mechanism of Magnus phenomenon and effects of the rotation on the lift and drag were analyzed by surface pressure distribution analysis of the missile body.The impact on lift and drag is little,and the impact can be neglected.Influences of Magnus effect on surface pressure distribution of projectile were obtained while different angle of attack,Mach number and spinning speeds varying.The result shows that boattail is the main impact part of Magnus effect.The Magnus force and moment coefficients vary linely with attack angle and spinning speed,and the influence of rotation effect on projectile becomes smaller and smaller with the increase of Mach number.The empirical formulae of Magnus force and moment coefficients for small attack angle and supersonic cases were put forward and verified,which can provide guidance for corresponding design and improvement of spinning projectiles.