变转速旋翼气动特性分析及试验研究  

Analysis and Experimental Investigation on the Aerodynamic Characteristics of Variable Speed Rotor

作　　者：徐明[1] 韩东[1] 李建波[1] 

机构地区：[1]南京航空航天大学直升机旋翼动力学国家级重点实验室,江苏南京210016

出　　处：《航空学报》2013年第9期2047-2056,共10页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(11202097);航空科学基金(2011ZA52004)~~

摘　　要：直升机旋翼以固定不变的转速工作,仅能使有限状态的旋翼效率达到最优,而通过旋翼转速的变化,可以实现不同飞行状态下的旋翼效率最优。为了研究不同旋翼转速时的旋翼气动特性,首先建立了适合旋翼在低转速飞行情况下的气动特性分析模型,该模型包含了Leishman-Beddoes非定常动态失速模型与适合于低马赫数(Ma<0.3)分析的Sheng失速修正模型;其次,在低速风洞2.5m旋翼模型试验台上试验研究了模型旋翼的悬停效率及前飞需用功率与旋翼转速之间的关系。试验与计算结果的对比表明:所建立的气动分析模型能够准确地计算旋翼在低转速情况下的气动特性;通过优化旋翼转速,增大了桨叶剖面迎角,提高了桨叶剖面的升阻比;并且当旋翼以最优转速旋转时,模型旋翼的悬停效率最大可以提高32%,前飞需用功率最大可以降低22%。When helicopters work at fixed rotor speeds, optimal rotor efficiency cannot be achieved in all flight states. It can only be realized at different flight states by varying rotor speeds. In order to investigate the aerodynamics of variable speed rotors, an analytical model applying to low speed rotors is first derived. The Leishman-Beddoes unsteady and dynam- ic stall model and a modified Sheng dynamic stall model for low Mach numbers （Ma〈0.3） are introduced. Then, a test in a 2.5 m diameter helicopter rotor model test rig at a low speed wind tunnel is conducted, and the effects of rotor speeds on the figure of merit and the rotor power required are investigated. Finally, the comparisons between the experimental data and calculation demonstrate that the aerodynamic characteristics for low speed rotors can be accurately predicted by the analyti- cal model. By optimizing the rotor speed, the lift to drag ratio of an airfoil can be effectively improved by the increase of the angle of attack. When the rotor is working at the optimal rotor speed, the figure of merit can be improved by 32% and the rotor power can be maximally reduced by 22%.

关 键 词：变转速旋翼 气动特性 动态失速 最优转速 悬停效率 功率 

分 类 号：V211.52[航空宇航科学与技术—航空宇航推进理论与工程]