直升机涵道尾桨气动噪声特性风洞试验研究

Experimental study on aerodynamic noise characteristics of helicopter ducted tail rotor

基于中国航空工业空气动力研究院FL–52航空声学风洞试验条件,对直升机涵道尾桨模型的气动噪声特性进行了试验研究。对试验数据进行了射流剪切层影响修正,获得了涵道尾桨在悬停、前飞状态下的噪声频谱及远场指向性。分析了噪声随桨尖马赫数的变化规律,结果显示涵道尾桨气动噪声符合载荷噪声特性。对比了桨叶沿桨毂周向分布规律对气动噪声频谱特征的影响。获得了悬停和前飞状态下涵道对噪声传播的遮蔽效果影响,悬停状态下尾桨旋转平面内噪声降低约2 dB,前飞状态下尾桨旋转平面内噪声降低5~8 dB。

Using the FL–52 aero-acoustic wind tunnel test system of the Aerodynamics Research Institute,the experimental study on the ducted tail rotor noise characteristics is carried out.The influence of the jet shear layer on the test data is corrected,and the noise spectrum and far-field directivity of the culvert tail rotor in hover and forward flight are obtained.The variation laws of the noise with the Mach number of the tail rotor tip are analyzed,and the results show that the aerodynamic noise of the ducted tail rotor conforms to the load noise characteristics.The effects of the blade distribution along the hub on the spectral characteristics of the aerodynamic noise are compared.The shielding noise reduction effect of the duct on the noise propagation under typical working conditions is obtained in hover,the noise in the rotating plane is 2 dB lower than that in other positions in forward flight,the noise reduction in the rotating plane is 5–8 dB.