Flow instability and aerodynamic performance deterioration in transonic compressors are often triggered by the interaction between tip leakage vortices and shock waves. To mitigate these issues, this study investigates a transonic compressor linear cascade and proposes a flow-control strategy based on a bump–winglet configuration. The geometry is optimized with the objective of minimizing total pressure loss near stall, and the regulation mechanism of vortex–shock interaction is examined using a validated numerical method. The results show that the optimized cascade reduces aerodynamic losses across the entire incidence range, from the design point to near-stall conditions. At near-stall incidence, the total pressure loss coefficient decreases by 3.13%, while the static pressure coefficient and overall pressure rise increase by 2.20% and 0.28%, respectively. The stable operating range is also extended by more than 0.5°. Compared with the original cascade, the optimized cascade significantly reduces the axial extent of the low-pressure core on the suction side. The onset of the low-pressure core is delayed by 40.68%, and its spatial range is reduced by 46.55%. These changes effectively restrict the development of leakage flow inside the passage and substantially enhance flow-field stability. Furthermore, compared with using the bump or the winglet alone, the combined bump–winglet structure can generate a synergistic effect, achieving a performance improvement greater than the sum of their individual contributions.
Yang et al. (Thu,) studied this question.