基于小波分析的多级轴流压气机内部噪声特性研究

Investigation on internal noise characteristics of a multistage axial compressor based on wavelet analysis

基于刚性壁声波导管技术,通过直接对压气机内部噪声进行测量的方法,开展了对某型多级轴流压气机部件试验的内部噪声信号特性的研究。利用小波分析方法所具有的时-频和多分辨率的特点,结合压气机内部噪声信号频率成分的研究,论证了小波分析方法对噪声信号分析研究的有效性。根据非定常流旋涡脱落理论和小波分析的结果,认为压气机流道内部的噪声主要是由转子叶排非定常旋涡脱落引起的,频谱中的主要特征峰值是旋涡脱落频率以及其与通过频率迭加后所衍生出来的一系列特征频率。最后给出了不同转速工况下主要的特征峰值的频谱演化过程以及其随转速的变化相应的幅值变化特性,分析成果对非定常流场特性的进一步研究有一定的参考价值。

Based on the rigid wall acoustic waveguide technique, this paper carries out the research of the in- ternal noise characteristics of a multistage axial compressor through the direct measurement of compressor＇s internal noise data. Considering the good performance of wavelet analysis in time-frequency and multi-reso- lution domain,the analysis of the compressor＇s internal noise in the axial flow component testing is success- fully realized, and the wavelet analysis proves to be effective. Combining the theory of the vortex shedding of the unsteady flow and the results of the wavelet analysis, the paper proves that the intemal noise of com- pressor is mainly caused by unsteady vortex shedding of the rotor row, and the main featured peaks of the frequency spectrum are the vortex shedding frequency and a series of special frequencies derived from the superposition of vortex shedding frequency and the BPF. At last, with different speeds, the evolution of the main peak frequency spectrums and its corresponding amplitude variations are given. The conclusions will provide certain reference for further understanding of the characteristics of unsteady flow field.