Influence of boundary layer suction on unsteady flow field of a compressor cascade

Abstract The aspirated compressor is one of the effective technological approaches for breaking through the loading limits of conventional compressors. In this study, unsteady flow field simulations with boundary layer suction were conducted for a compressor cascade exhibiting trailing edge separation. The numerical results demonstrate that the simulations successfully capture the vortical structures within the turbulent boundary layer on the suction surface, and that the trailing edge shedding vortices originate primarily from the suction surface. With increasing incidence, the onset location of vortices on the suction surface moves upstream toward the blade leading edge, and the shedding vortices downstream of the cascade become more irregularly distributed. After the application of boundary layer suction, a paired Kármán vortex street forms at the blade trailing edge. Meanwhile, the temporal pressure signals at the monitoring points exhibit clear periodicity, with a significantly increased dominant frequency and a substantially reduced amplitude.