Influence of mixed dimples on aerodynamic performance of high-load compressor cascade

• Published in: Aerospace science and technology Vol. 154; p. 109492
• Main Authors: Shi, Yuanpeng, Lu, Huawei, Peng, Benli, Kong, Xiaozhi, Wang, Long
• Format: Journal Article
• Language: English
• Published: Elsevier Masson SAS 01.11.2024
• Subjects: Dimpled cascade; Five-hole probe; High-load compressor cascade; Vortex structure; Wind tunnel test; Vortex structure; High-load compressor cascade; Dimpled cascade; Five-hole probe; Wind tunnel test
• ISSN: 1270-9638
• DOI: 10.1016/j.ast.2024.109492

•The aerodynamic performance parameters of the outlet of the prototype cascade and the mixed dimpled cascade are measured. Compared with the prototype cascade, the total pressure loss of the dimpled cascade at all attack angles was reduced.•Combined with the oil flow test on the cascade surface, the distribution law and fluid composition of vortex structure in the cascade channel are analyzed. The three-dimensional schematic diagram of vortex structure in cascade channel is provided.•Mechanism of mixed dimples is provided. The boundary layer is disturbed, and the boundary layer transition occurs ahead of time, induced by the mixed dimples. The anti-separation ability of the fluid was enhanced, and the separation bubbles on the suction surface were eliminated. In this study, the effect of mixed dimples on the aerodynamic performance of a high-load compressor cascade, named National Advisory Committee for Aeronautics 65-K48, at different attack angles was numerically and experimentally investigated. Mixed dimples with four columns and eight rows were arranged at 10% to 32% of the chord length of the half-blade height. The performance parameters of the cascade outlet section and vortex structure inside the cascade were exploited. The results reveal that the boundary layer is disturbed, and the boundary layer transition occurs ahead of time, induced by the mixed dimples. The anti-separation ability of the fluid was enhanced, and the separation bubbles on the suction surface were eliminated. Meanwhile, the lateral secondary flow was inhibited, and the intensities of the passage and concentrated shedding vortices were consequently reduced. Compared with the prototype cascade, the total pressure loss of the dimpled cascade at all attack angles was reduced. The total pressure loss can be reduced by nearly 20% at –9°.