后掠叶片锯齿尾缘宽频噪声实验研究

本文采用线性传声器阵列分别对具有常规尾缘及锯齿形尾缘的后掠叶片的尾缘噪声进行了实验测量;运用CLEAN-SC数据处理方法精确地识别出叶片尾缘噪声的声学参数.并且基于多组实验结果的对比,深入研究了不同的尾缘锯齿长度、周期、几何比例对后掠叶片尾缘噪声降噪效果的影响.实验结果表明:在低湍流度、自由来流情况下,在总声压级降噪方...

Experimental Study on Broadband Noise Reduction of Swept Blade With Serrated Trailing Edge

In this paper,the trailing edge noise of the swept blade with conventional trailing edge and serrated trailing edges is measured experimentally by linear microphone array;and the acoustic parameters of trailing edge noise of swept blade are accurately identified by the CLEAN-SC algorithm.Based on the comparison of multiple sets of experimental results,the influence of different amplitudes,widths and geometric ratios of the serrated trailing edge of swept blade on the noise reduction effect is studied in depth.The experimental results show that in the case of low turbulence intensity and free upcoming flow,in consideration of overall sound pressure level,the longer the amplitude of serrations,the more obvious the noise reduction effect;the bigger the serration width,the better the noise reduction effect of trailing edge.For the same geometric ratio of the trailing edge serrations,the larger the overall size of serrations,the better performance the trailing edge noise reduction.For a specific swept blade,there must be an optimal size of the serrated trailing edge which can reduce the noise most.In all experiments,the maximum Sound Pressure Level(SPL)reduction is 1.2 dB.Moreover,the noise reduction effect of“stream-wise”trailing edge serration is far better than the“symmetric”serration,and all“symmetric”serrations never have a noise reduction effect.