To study stall inception of the axial flow compressor

full-annulus numerical simulation in the first stage of a two-stage low-speed axial flow compressor was presented. Results showed that there existed a kind of velocity fluctuation in the circumference scale in stall inception

which was closely related to the uneven boundary layer separation that first happened on the suction of stator blade rows. With further throttling of the compressor

the fluctuation amplitude increased gradually

and eventually it induced several rotor channels to generate serious boundary layer separation

blocking these channels. The compressor system led to the rotating stall condition. The rotational stall frequency with full development had good coincidence with the experimental result.