Through numerical investigations on the characteristics of tip leakage flow oscillation in a low speed axial compressor

it was found that at large flow rate conditions

the tip flow field did not vary with time. As flow rate decreased

the tip flow field gradually started to fluctuate

meanwhile the tip leakage flow oscillated periodically

showing that the origin position

vortex structure pattern and impinging position on the pressure surface of neighboring blade changed with time. The tip leakage vortex and its detached vortex induced low pressure regions on the neighboring blade surface

leading to the oscillation of pressure distribution in blade tip region. Then this also affected the generation of the tip leakage flow in the neighboring passages. The interaction effect of tip leakage flow and the neighboring blade was the main cause of the tip flow field fluctuation. Furthermore

the tip leakage flow oscillations had phase lag between neighboring blade passages

which induced a flow disturbance with non-blade-number periodicity propagating circumferentially around the rotor.