变转速旋翼直升机性能及配平研究

 为研究变转速旋翼直升机性能及配平特性,本文以旋翼动力学综合模型为基础,研究了样例变转速旋翼直升机旋翼需用功率随旋翼转速、前飞速度、起飞质量和飞行高度的变化,以及旋翼总距、纵横向周期变距和桨轴纵横向倾斜角随旋翼转速和前飞速度的变化关系。研究结果表明,降低旋翼转速可明显降低旋翼需用功率,有利于提高直升机航时、航程和升限等性能指标。旋翼转速变化对直升机配平影响明显,配平限制了旋翼工作于过低的转速,另一方面,旋翼转速过低反而有可能增加旋翼的需用功率。旋翼总距和纵横向周期变距随旋翼转速的降低而加大,旋翼桨轴的纵向倾斜角随转速变化不大,横向倾斜角随旋翼转速的降低而减小。

Study on the Performance and Trim of Helicopters with Variable Speed Rotors

To investigate the performance and trim characteristics of helicopters with variable speed rotors, this paper makes a study of the rotor power with variable rotor speed, forward speed, helicopter weight and fight altitude as well as the pitch controls and tilt of rotor shaft with respect to rotor speed and forward speed based on a comprehensive rotor modeling. The results indicate that significant power reduction is achieved by the reduction of rotor speed, which can be utilized to improve the endurance, range and flight altitude of helicopters. The variation of rotor speed has significant influence on the trim of helicopters. The trim limits the rotor working at very low rotor speeds,which may incur the increase of the rotor power. The collective and cyclic pitches increase with decreasing rotor speed. The variation of the longitudinal tilt of the rotor shaft with rotor speed is not obvious, and the lateral tilt decreases with decreasing rotor speed.