直升机抛射物体平衡及稳定性分析

基于部件级建模理论建立了建立直升机-外挂装置系统六自由度飞行动力学模型。对所建模型进行了配平计算，与参考数据进行了对比。计算分析了不同速度下采用不同方式抛射物体时直升机的稳定性。结果表明，单侧抛射由于反冲力不对称，抛射物体对于直升机的滚转角和横向周期变距有显著的影响；随飞行速度增大，抛射物体对于直升机横向荷兰滚模态稳定性影响增大，当前飞速度达到50m/s以上时，荷兰滚模态演变为两个发散的非周期模态，稳定性明显变差，直升机应在较低速度下抛射物体。 

Analysis on trim and stability of helicopter casting objects

A six freedoms flight dynamics model for a helicopter with pylons was built based on the theory of component-level. Trim calculation was conducted, and the result compared with the existing conclusion. Stability was analyzed for the helicopter casting objects with different patterns at different flight velocities. The result indicated that there was great effect on rolling angle and lateral control-stick when the helicopter cast objects by one-side due to the asymmetry of the recoil force. With the increase of the forward-flight velocity, casting objects had a greater effect on Dutch mode. Dutch mode evolved into two divergent aperiodic modes as the helicopter cast objects at a velocity higher than 50m/s, flight stability became worse obviously. The helicopter should cast objects at a lower velocity.