锯齿尾缘构型降低圆柱-叶栅干涉噪声的实验研究

Experimental Study on Reducing Cylinder-Cascade Interference Noise with Serrated Trailing Edge Configuration

关键词:  锯齿尾缘  声源识别  干涉噪声  传声器阵列  仿生学降噪

Key words:  Serrated trailing edge  Sound source identification  Interference noise  Microphone array  Bionics noise reduction

摘要:

通过在叶栅上游放置圆柱产生各向异性的湍流尾迹，并与下游叶片相互干涉产生干涉噪声，研究了仿生学锯齿尾缘构型对圆柱-叶栅干涉噪声的影响。针对西北工业大学航空叶轮机气动力学与气动声学实验室（TAAL）低压涡轮平面叶栅，在不同来流速度的情况下，使用远场圆弧阵列测量了叶栅远场噪声，并基于CLEAN-SC数据处理算法使用由31个传声器组成的线阵列测量识别了不同叶栅的尾缘噪声，得到了圆柱尾迹来流下锯齿尾缘构型的降噪效果。实验结果表明，不同锯齿尾缘构型的降噪效果存在差异，当来流为圆柱尾迹时，对叶栅尾缘噪声的识别测量结果显示此时锯齿尾缘降噪效果有限，最佳降噪量仅为1.296dB，当来流速度较高时，采用的锯齿尾缘构型无法降低圆柱-叶栅干涉尾缘噪声。

Abstract:

The influence of bionic serrated trailing edge configuration on cylinder cascade interference noise is studied. A cylinder was placed upstream of the cascade to produce anisotropic turbulent wake and then the anisotropic turbulence interfered with the downstream blade to produce interference noise. For the low-pressure turbine plane cascade of the Turbomachinery Aerodynamics & Acoustics Laboratory （TAAL） of Northwestern Polytechnical University， a far-field arc array was used to measure the far-field noise of the cascade under the condition of different incoming flow velocities. And based on the CLEAN-SC array data processing algorithm， the trailing edge noise of different cascades was identified by using the line array which composed of 31 microphones， and the noise reduction of serrated trailing edge configurations under the cylindrical wake was obtained. The experimental results show that the noise reduction of different serrated trailing edge configurations is different. When the incoming flow was cylindrical wake， the measurement results of cascade trailing edge noise show that the noise reduction of the serrated trailing edge is limited， and the optimal noise reduction is only 1.296 dB. When the incoming flow velocity was relatively high， the serrated trailing edge configuration used in this paper cannot reduce the cylinder-cascade interference noise.