B312 TWO KIND OF ROTATING STALL CHARACTERISTIC ANALYSIS OF CENTRIFUGAL FANS BASED ON HARMONIC WAVELET

Abstract

In this paper two kind of rotating stall of blade row is tested on a 4-73No8D centrifugal fan in lab. In order to extract feature of rotating stall of 4-73 fan series, orthogonal harmonic wavelet and the reformed non-orthogonal HW, the delay rate of which in time domain is improved by author, are introduced to analyze time-frequency characteristic of different stall. The time-frequency feature of two kind of stall is obtained and the effectiveness and advantage of harmonic wavelet applying to analyze the unstable flow of centrifugal fans is proved.