Analysis of bump–winglet synergistic control in a transonic compressor linear cascade based on vortex–shock interaction

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.