Experimental measurements were conducted for an axial high-speed subsonic compressor rotor on the ground. Numerical investigations were carried out at two altitudes to explore the mechanism of circumferential propagation characteristic at different Reynolds number (Re). Results showed that

on the ground

rotating instability (RI) was measured near stall condition

which was characterized by a hump frequency band in the spectrum. Characteristic frequencies of numerical pressure signals were limited in the frequency band of RI on the ground. The spectrums of the neighboring passages indicated that the flow unsteadiness rotated in the compressor. The circumferential disturbance was result of the periodic interaction between the blade tip leakage flow and the blade tip load. At the altitude of 20 km

there were several circumferential disturbances with different characteristic frequencies in the compressor near stall condition. The radial flow from the hub to tip induced by the suction surface flow separation was dominant in the tip region. The blade tip load was influenced both by the radial flow and tip leakage flow

as a result of the circumferential disturbance at low Re.