直升机前飞状态旋翼结冰风洞试验研究

为研究直升机旋翼在不同前飞状态的结冰情况，研制了直升机旋翼模型结冰试验台，在中国空气动力研究与发展中心结冰风洞4.8 m×3.2 m试验段中进行了旋翼结冰风洞试验。以某型直升机2 m直径旋翼缩比模型为试验对象，分析了旋翼转速、初始拉力系数对旋翼结冰的影响。结冰试验过程中保持旋翼操纵恒定，利用天平测量了旋翼拉力和扭矩性能的动态变化，并采用二维冰形切割及三维冰形扫描的方式分别测量了桨叶展向典型剖面的翼型及桨叶的整体结冰形态。试验得到了旋翼结冰关键数据，分析结果表明:旋翼桨叶结冰主要集中在桨叶前缘和下表面，结冰会在降低旋翼升力的同时增大旋翼扭矩和功率；小拉杆杆端轴承的积冰可能造成卡塞，变距拉杆上的积冰可能造成杆端轴承卡塞，从而使旋翼操纵失效。 

Icing wind tunnel investigation of helicopter rotor model in forward flight state

To investigate the effect of ice accretion on helicopter rotors in forward flight in different flight states, a helicopter rotor icing test system was developed. A rotor model icing test was conducted in the 4.8 m× 3.2 m test section of the China Aerodynamics Research and Development Center icing wind tunnel. The effect of the rotational speed and initial thrust on the performance of a 2 m-diamter rotor model was examined. During the icing test, the control angle of the rotor was maintained constant, and the dynamic variation of the rotor thrust and torque was measured by a balance. The ice shape of the airfoil at typical span stations and of the entire blade was measured by two-dimensional ice cutting and three-dimensional scanning system, respectively. Test results showed that ice accretion occurred primarily on the blade leading edge and lower surface, and that icing increased rotor torque and power while decreasing rotor thrust. The rod end bearing of the pitch link could be stuck by accreted ice, resulting in a loss of rotor control.