Passive Control with Blade-End Slots and Whole-Span Slot in a Large Camber Compressor Cascade

Suitable slot structure of the compressor blade can generate highmomentum jet flow through pressure difference between the pressure and suction surface, it has been proved that the slot jet flow can reenergize the local lowmomentum fluid to effectively suppress the flow separation on the suction surface. In order to explore a slotted method for better comprehensive suppressing effects on the boundary layer separation near blade midspan and the threedimensional corner separation, a diffusion stator cascade with large camber angle is selected as the research object. Firstly, the Slotted_1 and Slotted_2 wholespan slotted schemes are set up, then the Slotted_3 scheme with wholespan slot and bladeend slots is proposed, finally the performance of original cascade and slotted cascades is computed under a wide range of incidence angles at the Mach number of 0.7. The results show that: in the full range of incidence angles, compared with the wholespan slotted cascades, the development of the endwall secondary flow on the suction surface of Slotted_3 cascade is effectively suppressed, the degree of the mutual interference between the secondary flow and the main flow is reduced. Besides, on the suction surface of Slotted_3 cascade, the boundary layer separation near blade midspan and the corner separation are basically eliminated. As a result, compared with those of original cascade, the total pressure losses of Slotted_3 cascade are reduced in the full range of incidence angles, and its operating range of incidence angles is broadened. Moreover, compared with the wholespan slotted schemes, Slotted_3 scheme has a better adaptability to wide range of incidence angles.