Numerical investigation into the mechanism of spike-type stall inception in an axial compressor rotor

Whole-passage simulations were conducted to simulate the stall inception process in a subsonic compressor rotor. The predicted results agreed well with available steady-state and time-resolving experimental data. The detailed flowfield analyses further demonstrated that the test rotor was of spike-type stall inception. The self-sustained unsteady cycle of tip separation vortex (TSV) was the underlying flow mechanism for the occurrence of the so-called 'tip clearance spillage flow' and 'tip clearance backflow'. Furthermore, the correlation between the selfsustained cycles of TSV in the preceding and native passages was the flow mechanism for emergence of spike. For the test rotor, the distinctive flowfield feature during the development of spike was the involvement of 'tip clearance back-spillage flow'.