In t his p aper r otating s tall a nd t he inlet v ortex in c entrifugal fans with inlet v ane control has been studied in laboratory . the harmonic wavelet is firstly used for time - frequency analysis and feature extraction of pulsation amplitude and frequency and development of rotating stall and inlet vortex . the development rule of rotating stall and inlet vortex and the effect to fans performance from the two has been found 文中对采用入口导流器调节的离心通风机的旋转失速和进口涡流问题进行了实验研究，并借助谐波小波对旋转失速和进口涡流的频率、幅值特性及动态过程进行了时频分析和特征提取，揭示了旋转失速和进口涡流发展的规律及二者对风机性能的影响。
