抄録
There are two types of stall inception in axial compressors. The first one is characterized by long length-scale disturbances called as "modal waves", and the second one is by a short length-scale distrubance known as "spike". In this paper, the development of rotating stall when varying the gap length between a rotor and an upstream stator is investigated by the wavelet analysis of the casing wall pressure signals. The route leading to stall switches from short to long wavelenghth with changing the gap length. In deep stall condition, these two disturbances are interfered with each other regardless of the gap length.
