直－九直升机地面共振当量模型及稳定性分析

Equivalent Model Establishment and Ground ResonanceInvestigation for Z-9 Helicopter

本文推导了直升机地面共振当量模型中的当量质量、当量刚度与当量阻尼的计算公式，分析了机体动力特性及其主要影响因素，并运用当量地面共振二维模型计算了直一九直升机旋翼／机体耦合地面共振稳定性。在此基础上分析了机体阻尼与旋翼阻尼各自对直－九直升机地面共振稳定性的影响。计算与分析结果表明，未国产化的直－九直升机在使用范围内不会发生地面共振，这与直一九宜升机实际使用情况相符合。所用计算模型及计算机程序可直接用于直－九直升机国产化中地面共振稳定性分析。

The calculation formula of equivalent mass, stiffness and damping are derived for Z-9 helicopter equivalent model. The main factors imposing effect on the body dynamics are analyzed. The equivalent two dimensional model of ground resonance are used to investigate the Z-9 rotor/body coupled ground resonance stability. Based on the calculation the influences of the body damping and the rotor damping on the stability are analyzed separately. The conclusion of the calculation and analysis indicates that Z-9 helicopters which are not nationalized in production is stable with in the normal operation range in fair agreement with the practical operation. The model and program can be used directly in stability analysis of ground resonance for Z-9 helicopter.