直升机吊挂飞行稳定性和操纵性分析

摘要

建立直升机吊挂飞行的直升机/吊挂物/吊索耦合飞行动力学模型.其中直升机基本飞行动力学模型,包括挥、摆耦合的旋翼桨叶挥舞、摆振模型和弹性扭转模型,采用动态入流理论的旋翼尾迹模型,并考虑了旋翼尾迹对吊挂物的影响,还有直升机六自由度运动模型;建立了吊挂物刚体运动模型和根据风洞实验结果确定的吊挂物气动力模型,吊索采用柔索模型.在此基础上,比较了无吊挂配平操纵量与实验结果和吊挂飞行配平计算结果,分析了吊挂物对直升机平衡稳定性的影响以及直升机质心位置和吊点位置对稳定性的影响,在频城里进行了吊挂飞行的操纵性分析,计算结果与飞行实测进行了对比,二者吻合较好.%A coupled mathematical model of helicopter, slung load and sling motions is developed for helicopter slung load flight. In the basic helicopter flight dynamic model, the flag and lag coupled model and the blade torsion model are developed. A three state dynamic inflow model of the main-rotor wake is used. The influence of rotor wake on the slung load is considered. The six degree-of-freedom equations of motion of the aircraft and slung load are developed. The aerodynamic load applied on the slung load is determined based on wind tunnel test. Elastic cable models of sling are developed. The trim results without slung-load are compared with flight test results and the slung-load flight condition. The relationship between the stability characteristics and the location of the helicopter center of gravity and the slung-load lift points is discussed. The frequency domain response validation with flight test is conducted. The computed results are in good agreement with flight test results.