Effects of rotating inlet distortion on the stall mechanism of an axial flow compressor

Abstract

To study the influence of rotating inlet distortion on a single-stage axial compressor, both experiment and full-annulus unsteady simulation methods are carried out to reveal the stall mechanism under different inflows. First, the experimental results show that compared with static distortion, rotating distortion reduces the compressor stall margin more seriously. The wavelet analysis of dynamic pressure data shows that although the addition of inlet distortions has changed the stalling process, the compressor still stalls through spike-type. The full-annulus unsteady simulations indicate that the low-velocity zone first appears at the hub under uniform inflow condition. When the compressor is subjected to rotating distortion, the low-velocity zone first appears at the tip region. Time-averaged solutions of unsteady simulations are further studied to reveal the underlying mechanisms. Compared with the flow field under uniform inflow, the addition of rotating distortion can produce co-swirl, but it also causes the change of axial velocity distribution along the radial direction. Under the combined effect of both, the blade loading of rotor tip increases significantly, altering the position where the low-velocity zone first appears.