机场道面外来物撞击航空发动机转子叶片速度估算

Velocity Estimation for the Impact of Foreign Object against the Aero-engine Blade

针对机场道面外来物对航空发动机转子叶片的撞击损伤规律进行研究。以试验结果为基础,研究了空气旋流使外来物从地面加速运动至飞机进气道口的速度,然后利用动量定理推导了外来物从飞机进气道口至发动机转子叶片的速度方程;以叶片为参考系,建立了外来物撞击速度及撞击角度的表达式。最后,以某型飞机及其发动机为例,研究了外来物到达发动机一级转子叶片的速度变化规律,实验结果发现:外来物的运动速度不仅与外来物的材质、形状、大小有关,而且与飞机进气道距地面高度、进气道长度、发动机工作状态密切相关;外来物撞击叶片的方向与叶片表面不垂直。

In order to overcome the defect that the impact velocity is assumed between blades and foreign object in present method, and to deeply search the law for an aero-engine blade impacted by the foreign ob- ject from the runway, the impact velocity of foreign object against the aero-engine blade is estimated in the paper. Firstly, taking the tested results as a basis,velocity induced by the air vortex from the runway surface to the inlet port is studied. Then, velocity equation from the inlet port to the blade is deduced by using the momentum theorem. Taking a blade as a reference, expressions of both the impact velocity and the im- pact direction relative to the blade are found. At last, a certain type of the airplane and its aero-engine are taken as example, the change rule of the motion velocity in inlet channel is studied. The results show that the foreign object motion velocity relates not only with the foreign object shape, dimension and material, but also with the aero-engine working state, the height and the length of the inlet port. The impact direction is out of vertical to the blade surface.