砂尘在典型金属壁面上的反弹特性仿真研究

含有砂尘的空气吸入发动机,会与叶片、内外机匣之间不可避免发生碰撞,影响飞行器飞行安全。通过采用显式动力分析有限元法,建立砂尘以不同入射角度、入射速度、粒径大小及其旋转速度撞击壁面的反弹模型,研究砂尘在不同条件下与不锈钢及铝合金面碰撞后的反弹特性结果,为预测砂尘在粒子分离器中的运动轨迹提供反弹特性数据支持。结果表明:随砂尘入射速度增大,反弹速度呈增大趋势,速度恢复系数基本保持稳定;相同入射条件下,铝合金材料对砂尘速度恢复系数的影响小于不锈钢材料;旋转速度、砂尘粒径对其碰撞反弹特性影响微弱,可以忽略不计;决定砂尘反弹角度仅取决于碰撞姿态和砂尘入射角度。

Simulation Study of Rebound Characteristics of Sand and Dust on Typical Metal Wall

The air suction engine containing sand and dust will inevitably collide with the blade and the inner and outer casing,which will affect the flight safety of the aircraft.By using explicit dynamic analysis finite element method,the rebound model of sand and dust impacting on the wall with different incident angles,incident velocities, particle size and rotating velocities was established.The rebound characteristics of sand and dust impacting on stainless steel and aluminium alloy surfaces under different conditions were studied,which provided data support for predicting the trajectory of sand and dust in particle separator.The results show that the rebound velocity increases with the increase of the incident velocity of sand and dust,and the velocity recovery coefficient keeps stable basically;under the same incident condition,the influence of aluminum alloy on the velocity recovery coefficient of sand and dust is smaller than that of stainless steel;the impact of rotational velocity and particle size of sand and dust on the impact rebound characteristics is weak and can be neglected.The sand and dust rebound angle depends only on the collision attitude and incidence angle of sand and dust.