Effects of variable blowouts on aerodynamic loss reduction performance of compressor bionic blades

Abstract

A passive flow control method, inspired by blowouts, is employed to eliminate flow separation and reduced losses associated with higher compressor loads. By implementing bionic-blowout variant dimples on the blade suction surface, the flow characteristics of the dimple-shaped cascade were investigated. The loss generation mechanism was also analysed. Firstly, the reliability of the numerical method was confirmed through experimental validation. Subsequently, biomimetic principles were applied to arrange dimples on the suction surface of the cascade blades, and the effects of various blowouts were analysed The result revealed that vortices within the dimples induce external fluid into the dimples, enhancing the turbulent kinetic energy of the external fluid and improving wall-adjacent flow adherence. The bionic-blowout variant dimples creates a "rolling bearing" effect that reduces frictional losses, which control flow separation. Within a certain blowout range, the bionic-blowout variant dimples significantly improve the flow conditions. At -6° angle of attack, the total pressure loss of the dimple-structured cascade decreased by 35.85%, and the pressure ratio increased by 2.35%. The bionic-blowout variant dimples on the blade suction surface exhibit a three-dimensional disturbance effect. The induced vortex structures regulates the boundary layer transition and suppress the formation of laminar separation bubbles, effectively improving the flow conditions near the corner region.