Abstract: Some experiments show that a kind of special acoustic phenomenon, quite different from that of a normal conditiou of a compreeor, will appear on a compressor test in rotating stall condition. However, little has been known about these problems until now.An aeroacoustic model about the rotating stall of a compressor is described in this paper. The acoustic nature of rotating stall can be preliminarily explained according to this model. Based on the analysis of the nature of frequency and propagation of the sound from rotating stall, an acoustic measuring method for characteristic parameters, such as the number and propagation speed of stall cell, can be obtained. Compared with existing methods, it is an untouched measure without disturbing the flow. The initial experiment results obtained from a transonic axial compressor facility show that this method is feasible. The sound pressure produced by rotating stall is numerically analyed with the change of the width of stall zone, the number and propagation speed of stall cell.

Key words: compressor noise, compressor rotating stall, aeroacoustics