本研究旨在通過應用仿生魚鱗結構來優化壓縮機葉柵的流場特性，從而提升其性能和穩定性。隨著現代工業對高效能、高可靠性壓縮機的需求日益增長，傳統壓縮機在性能、效率和穩定性方面仍面臨諸多挑戰。通過仿生學的啟發，本研究利用OpenFoam數值模擬並透過速度場、壁面剪應力及渦流可視化等方法探討仿生魚鱗結構設計參數，包括魚鱗高度0.4mm至0.8mm，及魚鱗間距2、3和6mm，最終設計出具有減少二次流損失提升穩定性的壓縮機葉柵。
模擬結果表明，魚鱗結構設計在低高度0.4mm能保持減阻關鍵的回流區，且擁有較佳的局部流體加速效果。在魚鱗間距太大6mm的情況下，會失去部分回流區。因此，在低高度0.4mm與較近的間距2mm擁有最好的減阻效果。在仿生魚鱗葉柵方面，仿生魚鱗結構能夠有效減少二次流的損失，主要原因是其產生的渦流能抑制角分離線的發展，並減少馬蹄渦對二次流回流區及後續所發展的集中脫落渦的影響。但葉片的曲面外型，以及通道渦的影響，導致前方魚鱗所產生的流場有所偏差，葉片後緣的魚鱗無法在魚鱗之間產生完好的回流區。最終結果顯示，應用仿生魚鱗結構的葉柵在總壓損失方面明顯低於傳統葉柵，表明該結構具有良好的應用前景。
本研究不僅提供了一種新穎的壓縮機葉柵設計方法，還為未來的研究方向提供了重要參考。

As the demand for high-performance and reliable compressors grows, traditional designs face challenges in performance, efficiency, and stability. Inspired by biomimicry, this study employs numerical simulation using OpenFOAM to investigate the design parameters of a bionic fish-scale structure through methods such as velocity field analysis, wall shear stress evaluation, and vortex visualization. The parameters explored include fish scale heights ranging from 0.4 mm to 0.8 mm and scale spacings of 2, 3, and 6 mm. The goal is to develop a compressor cascade that reduces secondary flow losses and enhances stability.
The simulation results indicate that the fish-scale structure with a low height of 0.4 mm can maintain a crucial recirculation zone for drag reduction while also providing better local fluid acceleration. However, when the fish scale spacing is too large, part of the recirculation zone is lost. Therefore, the combination of a low height (0.4 mm) and closer spacing (2 mm) exhibits the most effective drag reduction. Regarding the bionic fish-scale cascade, the fish-scale structure effectively reduces secondary flow losses. This reduction is primarily due to the vortices generated by the scale structure, which suppress the development of the corner separation line and mitigate the impact of the horseshoe vortex on the secondary flow recirculation zone and the subsequent concentrated shedding vortices. The results demonstrate that the total pressure loss in a cascade with the bionic fish-scale structure is significantly lower than that of a conventional cascade.

1. Bhushan, B., Biomimetics: lessons from nature–an overview. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2009. 367(1893): p. 1445-1486.
2. Bushnell, D.M. and K. Moore, Drag reduction in nature. Annual review of fluid mechanics, 1991. 23(1): p. 65-79.
3. Zhang, M., et al., A review on modeling of bionic flow control methods for large-scale wind turbine blades. Journal of Thermal Science, 2021. 30: p. 743-757.
4. Cao, H., et al., Flow topology and noise modeling of trailing edge serrations. Applied Acoustics, 2020. 168: p. 107423.
5. Liu, Z., et al., Drag Reduction Performance of Triangular (V-groove) Riblets with Different Adjacent Height Ratios. Journal of Applied Fluid Mechanics, 2023. 16(4): p. 671-684.
6. Dong, J., et al., Flow control mechanism of compressor cascade: A new leading-edge tubercles profiling method based on sine and attenuation function. Physics of Fluids, 2023. 35(6).
7. Wu, L., et al., Water-trapping and drag-reduction effects of fish Ctenopharyngodon idellus scales and their simulations. Science China Technological Sciences, 2017. 60: p. 1111-1117.
8. Welahettige, P. and K. Vaagsaether. Comparison of OpenFOAM and ANSYS FLUENT. in Proceedings of The 9th EUROSIM Congress on Modelling and Simulation, EUROSIM. 2016.
9. Kurz, R. and K. Brun, Fouling mechanisms in axial compressors. 2012.
10. Herrig, L.J., J.C. Emery, and J.R. Erwin, Systematic two-dimensional cascade tests of NACA 65-series compressor blades at low speeds. 1957.
11. Hergt, A., et al. Advanced Study of Secondary Flow Structures in a Highly Loaded Compressor Cascade. in 11 th European Conference on Turbomachinery Fluid dynamics & Thermodynamics. 2015. EUROPEAN TURBOMACHINERY SOCIETY.
12. Meyer, R., et al., A parameter study on the influence of fillets on the compressor cascade performance. Journal of theoretical and applied mechanics, 2012. 50(1): p. 131-145.
13. Djedai, H., et al., Numerical investigation of three-dimensional separation control in an axial compressor cascade. International Journal of Heat and Technology, 2017. 35(3): p. 657-662.
14. Zambonini, G., Unsteady dynamics of corner separation in a linear compressor cascade. 2016, Université de Lyon.
15. Saha, U. and B. Roy, Experimental investigations on tandem compressor cascade performance at low speeds. Experimental thermal and fluid science, 1997. 14(3): p. 263-276.
16. Reutter, O., et al., Advanced endwall contouring for loss reduction and outflow homogenization for an optimized compressor cascade. International journal of turbomachinery, Propulsion and Power, 2017. 2(1): p. 1.
17. Zambonini, G., X. Ottavy, and J. Kriegseis, Corner separation dynamics in a linear compressor cascade. Journal of Fluids Engineering, 2017. 139(6): p. 061101.
18. Tang, Y., Y. Liu, and L. Lu, Solidity effect on corner separation and its control in a high-speed low aspect ratio compressor cascade. International Journal of Mechanical Sciences, 2018. 142: p. 304-321.
19. Peters, M., T. Schmidt, and P. Jeschke, Influence of blade aspect ratio on axial compressor efficiency. Journal of the Global Power and Propulsion Society, 2019. 3: p. 639-652.
20. Bechert, D., M. Bruse, and W. Hage, Experiments with three-dimensional riblets as an idealized model of shark skin. Experiments in fluids, 2000. 28(5): p. 403-412.
21. Modesti, D., et al., Dispersive stresses in turbulent flow over riblets. Journal of Fluid Mechanics, 2021. 917: p. A55.
22. Su, L., et al., Effect of undulating blades on highly loaded compressor cascade performance. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2021. 235(1): p. 17-28.
23. Hergt, A., et al., Riblet application in compressors: toward efficient blade design. Journal of Turbomachinery, 2015. 137(11): p. 111006.
24. Wang, C., et al., Implementation of flow loss minimization incorporating the riblet technique on cascade profile and experimental validation. Aerospace Science and Technology, 2023. 133: p. 108153.
25. Liu, Y., et al., Modified k-ω model using kinematic vorticity for corner separation in compressor cascades. Science China Technological Sciences, 2016. 59: p. 795-806.
26. Liu, Y., J. Sun, and L. Lu, Corner separation control by boundary layer suction applied to a highly loaded axial compressor cascade. Energies, 2014. 7(12): p. 7994-8007.
27. Weller, H., OpenFOAM: The Open Source CFD Toolbox User Guide. The OpenFOAM Foundation Ltd.: London, UK, 2010.
28. Wang, H., et al., Combined flow control with full-span slot and end-wall boundary layer suction in a large-camber compressor cascade. Aerospace Science and Technology, 2021. 119: p. 107121.
29. White, F.M., C. Ng, and S. Saimek, Fluid mechanics. 2011: McGraw-Hill, cop.
30. Herrig, L.J., J.C. Emery, and J.R. Erwin, Effect of section thickness and trailing-edge radius on the performance of NACA 65-series compressor blades in cascade at low speeds. 1951.
31. Lewin, E., D. Kozˇulovic´, and U. Stark. Experimental and numerical analysis of hub-corner stall in compressor cascades. in Turbo Expo: Power for Land, Sea, and Air. 2010.
32. Wang, H., et al., Effect investigation of single-slotted and double-slotted configurations on the corner separation and aerodynamic performance in a high-load compressor cascade. Aerospace Science and Technology, 2023. 135: p. 108203.
33. Liu, Y., et al., Effect of slot at blade root on compressor cascade performance under different aerodynamic parameters. Applied Sciences, 2016. 6(12): p. 421.
34. Zess, G. and K.A. Thole, Computational design and experimental evaluation of using a leading edge fillet on a gas turbine vane. J. Turbomach., 2002. 124(2): p. 167-175.
35. Marsh, H., Secondary flow in cascades-the effect of compressibility. 1975.
36. Koch, R., M. Sanjosé, and S. Moreau. Large-eddy simulation of a linear compressor cascade with tip gap: Aerodynamic and acoustic analysis. in AIAA Aviation 2021 Forum. 2021.
37. Zhou, H., et al., Research on the drag reduction property of puffer (Takifugu flavidus) spinal nonsmooth structure surface. Microscopy Research and Technique, 2020. 83(7): p. 795-803.
38. Muthuramalingam, M., L.S. Villemin, and C. Bruecker, Streak formation in flow over biomimetic fish scale arrays. Journal of Experimental Biology, 2019. 222(16): p. jeb205963.