正负尾桨距下尾桨两侧噪声特性试验研究

Noise Experimental Investigation on Both Sides of Tail Rotor for Positive/Negative Collective

开展正、负尾桨距条件下的尾桨噪声试验研究,并分析推力侧与拉力侧的尾桨噪声指向性差异。首先,在消声试验室中搭建了尾桨悬停状态噪声试验平台;其次,利用布置的传声器阵列,测量了不同传播距离下的噪声量级、尾桨拉力侧和推力侧不同观察角下的噪声水平以及尾桨在正负尾桨距和不同转速下的噪声水平。试验测量结果与理论分析吻合,试验结果表明在拉力侧和推力侧均存在噪声指向性,且拉力侧的噪声水平高于推力侧;在一些观察角下,噪声值不是在0°尾桨距时最小。

In this paper, noise experiment of tail rotor was carried out in the conduction of positive and negative collective. The noise directivities of tail rotor on the thrust and tension sides were also analyzed in the experiment. Firstly, the test platform was established in anechoic laboratory for hover state. Secondly, the noise levels against propagation distance and observation angle on both sides of the tail rotor were measured by using microphone array. Meanwhile, the noise levels at positive and negative collective and in different rotation speeds were also recorded. The test results were in agreement with the theoretical analysis. The test results show the follow conclusion. There are both noise directivities on the tension and thrust side, but the noise level of the tension side is higher than the thrust side. The minimum noise level was not at zero collective under some observation angles.