直升机对风切变的响应

The Response of Helicopter to windshear

本文研究了直升机对风切变的动态响应。文中采用两种不同的风切变模型,按规范要求,利用对数模型分析了直升机对风切变的动态响应,利用线性模型分析计算了风切变参数对直升机动稳定性特征根的影响。所用的桨叶具有水平铰外伸量,桨叶根部有弹性约束,且仅考虑桨叶的刚性挥舞运动。诱导速度在桨盘处的分布则采用王氏固定涡系涡流理论所导出的诱导速度非均布公式。本文对直升机动力学方程不作线化处理。 本文推导计及风切变速度的旋翼力和力矩、旋翼挥舞运动方程和直升机动力学方程,最后以某型直升机为算例,用较好的计算方法计算了平衡数据和稳定性特征根以及对风切变的响应,并分析了风切变参数对稳定性的影响。

The response of helicopter to windshcar is investigated in this paper. Two different windshear models are used. According to the specification logarithmic windshear model is used for calculating the response of helicopter to windshcar, linear windshear model is used for calculating the effects of windshear parameter on helicopter stability roots. An articulated rotor with a blade hinge offset from the center of rotation and with a spring about the flap hinge is considered and only rigid blade flapping motion is concerned. The nonuniform distribution of induced velocity on the rotor disk which is derived from the wang's generalized fix vortex theory is taken into account. The linear partial-differential small-perturbation equation is not used.In this paper, the detailed derivation of the expressions of rotor forces and rotor moments, the equations of the rotor flapping motion and the equation of helicopter which are all concerned with windshear are derived. The calculations of the trim data, the stability characteristic roots and the response of the helicopter to windshear for a helicopter model have been made. Analysis for the effects of windshear parameters on stability roots indicate some useful results.