Reducing frictional drag on aircraft surfaces has significant implications for enhancing aerodynamic efficiency and reducing fuel consumption. The work aims to systematically investigate the drag-reduction mechanism of spanwise triangular groove microstructures and focus on the optimization of groove geometric parameters to enhance their effectiveness. Previous studies primarily revealed the fundamental drag-reducing and drag-increasing mechanisms of these microstructures, but did not comprehensively investigate the specific effect of groove geometric parameters, or propose optimization strategies validated by experimental data. In contrast, this research extends earlier investigations by thoroughly exploring the effects of critical parameters, including groove depth, apex angle, and groove density, on frictional and pressure drag interactions. To explore the underlying mechanism, numerical simulations of the micro-scale flow fields around the spanwise triangular grooves were conducted with the Reynolds-Averaged Navier-Stokes (RANS) equations combined with the k-ε turbulence model. The simulations focused on evaluating the effect of groove microstructures on frictional drag, pressure drag, and total drag at various Mach numbers ranging from subsonic to supersonic conditions. The numerical results revealed that, at subsonic speed, the triangular groove microstructure induced stable micro-scale vortices within the grooves, significantly reducing the local shear rates at the wall surface, thus effectively decreasing frictional drag. However, the same microstructure caused an asymmetric pressure distribution within each groove, forming a distinct high-pressure region at the windward edge and a corresponding low-pressure region at the leeward edge. This asymmetry introduced additional pressure drag, which became increasingly significant as the Mach number rose to supersonic speed, ultimately outweighing the frictional drag reduction and causing an increase in total drag under high-speed conditions. A series of parameter optimization studies examined the effects of critical geometric parameters, including groove depth, apex angle, and groove density, on the drag characteristics. Simulation data demonstrated that a specific configuration of these parameters-namely, a groove depth of 20 µm, apex angle of 120°, and groove density ratio of 1∶2, achieved an optimized balance between reducing frictional drag and controlling pressure drag increases, thus improving overall drag-reduction effectiveness. To verify the computational findings experimentally, groove microstructures based on these optimized parameters were fabricated with a mold hot-pressing technique, resulting in precise microstructural films. These films were then applied onto specially designed wing-section models suitable for testing in the FL-3 continuous-flow trisonic wind tunnel. Experimental assessments of aerodynamic performance were conducted across multiple subsonic speeds (Mach numbers of 0.35, 0.45, 0.6, 0.8, and 0.9). The wind tunnel measurements provided direct evidence of drag reduction when compared to smooth control surfaces. Specifically, drag reduction rates for the grooved surfaces at these Mach numbers were quantified as 6.35%, 4.32%, 1.26%, 4.60%, and 4.00%, respectively. The results clarified the drag- reduction mechanism of spanwise triangular grooves, identifying the relationship between frictional drag reduction and the corresponding increase in pressure drag. The study provides optimized geometric parameters suitable for practical applications, which has been validated through wind tunnel experiments. However, at higher subsonic to supersonic speed, the pressure drag significantly increases, suggesting the necessity of further optimization to enhance performance across a wider range of flight conditions. Further studies are required to optimize groove geometries specifically for reducing the adverse effects of pressure drag at supersonic speed, thus improving the applicability of the triangular groove microstructures across a broader speed range.
Key words
functional surfaces /
aircraft drag reduction /
spanwise triangular grooves /
numerical simulation /
parameter optimization /
wind tunnel experiments
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References
[1] DUAN L, CHOUDHARI M.Effects of Riblets on Skin Friction and Heat Transfer in High-Speed Turbulent Boundary Layers[C]//50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition. Nashville, Tennessee. Reston: AIAA, 2012: 1108.
[2] MOHAMED G.Flow Control: Passive, Active, and Reactive Flow Management[M]. Cambridge: Cambridge University Press, 2000: 208-210.
[3] 秦立果, 刘建波, 李航, 等. 水下湍流减阻技术研究进展[J]. 表面技术, 2024, 53(16): 1-18.
QIN L G, LIU J B, LI H, et al.Research Advances in Drag Reduction Technologies for Submarine Turbulence[J]. Surface Technology, 2024, 53(16): 1-18.
[4] 杨海霞. 沟槽面湍流边界层减阻的数值研究[D]. 哈尔滨: 哈尔滨工程大学, 2008.
YANG H X.Numerical Study on Drag Reduction of Turbulent Boundary Layer on Groove Surface[D]. Harbin: Harbin Engineering University, 2008.
[5] 郭杰, 耿兴国, 高鹏, 等. 边界层控制法减阻技术研究进展[J]. 鱼雷技术, 2008, 16(1): 1-6.
GUO J, GENG X G, GAO P, et al.Recent Development of Drag Reduction Technologies via Boundary Layer Control[J]. Torpedo Technology, 2008, 16(1): 1-6.
[6] 徐成宇, 王永华, 焦远东, 等. 仿生鲨鱼皮表面的快速制备和减阻性能研究[J]. 表面技术, 2025, 54(5): 72-82.
XU C Y, WANG Y H, JIAO Y D, et al.Rapid Preparation and Drag Reduction Properties of Bionic Shark Skin Surfaces[J]. Surface Technology, 2025, 54(5): 72-82.
[7] 李玉磊, 南慧星, 卢家慧, 等. 纸基超疏水材料制备及应用的研究进展[J]. 包装工程, 2023(1): 23-32.
LI Y L, NAN H X, LU J H, et al.Research Progress on Preparation and Application of Superhydrophobic Paper[J]. Packaging Engineering, 2023(1): 23-32.
[8] 张宇姣, 董力群, 张亚军, 等. 基于数值模拟的超疏水材料减阻性能研究[J]. 表面技术, 2016, 45(11): 173-179.
ZHANG Y J, DONG L Q, ZHANG Y J, et al.Drag-Reducing Property of Super-Hydrophobic Material Based on Numerical Simulation[J]. Surface Technology, 2016, 45(11): 173-179.
[9] 汪家道, 禹营, 陈大融. 超疏水表面形貌效应的研究进展[J]. 科学通报, 2006, 51(18): 2097-2099.
WANG J D, YU Y, CHEN D R.Research Progress on Morphology Effect of Superhydrophobic Surface[J]. Chinese Science Bulletin, 2006, 51(18): 2097-2099.
[10] 潘光, 黄桥高, 刘占一, 等. 基于低表面能效应的疏水表面减阻机理[J]. 上海交通大学学报, 2011, 45(10): 1440-1443.
PAN G, HUANG Q G, LIU Z Y, et al.Drag Reduction Mechanism of Hydrophobic Surface Based on Low Surface Energy Effect[J]. Journal of Shanghai Jiao Tong University, 2011, 45(10): 1440-1443.
[11] 郝秀清, 王莉, 丁玉成, 等. 超疏水表面的减阻研究[J]. 润滑与密封, 2009, 34(9): 25-28.
HAO X Q, WANG L, DING Y C, et al.Study on the Dray Reduction of the Superhydrophobic Surface[J]. Lubrication Engineering, 2009, 34(9): 25-28.
[12] BODAVULA A, YADAV R.Numerical Investigation of the Effect of the Spanwise Groove on the Aerodynamic Characteristic of a Naca 0012 Airfoil Using γ-Reθt Transition Turbulence Model[J]. International Journal of Fluid Mechanics Research, 2022, 49(6): 1-17.
[13] 刘博, 姜鹏, 李旭朝, 等. 鲨鱼盾鳞肋条结构的减阻仿生研究进展[J]. 材料导报, 2008, 22(7): 14-17.
LIU B, JIANG P, LI X Z, et al.Drag-Reduction Bionic Research on Riblet Surfaces of Shark Skin[J]. Materials Review, 2008, 22(7): 14-17.
[14] 秦立果, 龚朝永, 孙红江, 等. 非光滑表面减阻研究进展[J]. 表面技术, 2022, 51(8): 107-122.
QIN L G, GONG C Y, SUN H J, et al.Review of Research on Drag Reduction of Non-Smooth Surface[J]. Surface Technology, 2022, 51(8): 107-122.
[15] BUSHNELL D M, MOORE K J.Drag Reduction in Nature[J]. Annual Review of Fluid Mechanics, 1991, 23: 65-79.
[16] 王巍, 崔申奥, 陈家华, 等. 仿生沟槽减阻研究现状与进展[J/OL]. 北京航空航天大学学报, 2025. https://www.cnki.com.cn/Article/CJFDTotal-BJHK20250307001. htm.
WANG W, CUI S A, CHEN J H, et al. Research status and progress of bionic groove drag reduction[J/OL]. Journal of Beijing University of Aeronautics and Astronautics, 2025. https://www.cnki.com.cn/Article/CJFDTotal-BJHK20250307001.htm.
[17] 封贝贝, 汪家道, 陈大融, 等. 仿羽毛沟槽薄膜减阻机理分析[J]. 功能材料, 2016, 47(5): 5001-5004.
FENG B B, WANG J D, CHEN D R, et al.Drag Reduction Mechanism of Feather-Like Riblet Film[J]. Journal of Functional Materials, 2016, 47(5): 5001-5004.
[18] LIU C K.An Experimental Study of Turbulent Boundary Layer on Rough Walls[D]. Stanford: Stanford University, 1966.
[19] VISWANATH P R.Riblets on Airfoils and Wings-A Review[C]//AIAA Fluid Dynamics Conference, 1999: 1-12.
[20] VUKOSLAVCEVIC P, WALLACE J M, BALINT J L.Viscous Drag Reduction Using Streamwise-Aligned Riblets[J]. AIAA Journal, 1992, 30(4): 1119-1122.
[21] WANG J, REN X, LI X, et al.Effect of Different Flow Directions on Drag over Riblet[J]. Journal of Applied Fluid Mechanics, 2020, 13(3): 957-967.
[22] PARK J, CHOI H.Effect of the Yaw Angle on the Riblet Performance[J]. Physics of Fluids, 2024, 36(6): 065110.
[23] 史小军, 王树立, 李恩田, 等. 肋条在湍流减阻中的数值模拟[J]. 管道技术与设备, 2008(1): 8-10.
SHI X J, WANG S L, LI E T, et al.Numerical Simulation of Horizontal Riblets in Turbulent Drag Reduction[J]. Pipeline Technique and Equipment, 2008(1): 8-10.
[24] MOHAMMADI A, FLORYAN J M.Groove Optimization for Drag Reduction[J]. Physics of Fluids, 2013, 25(11): 113601.
[25] 潘家正. 湍流减阻新概念的实验探索[J]. 空气动力学学报, 1996, 14(3): 304-310.
PAN J Z.The Experimental Approach to Drag Reduction of the Transverse Ribbons on Turbulent Flow[J]. Acta Aerodynamica Sinica, 1996, 14(3): 304-310.
[26] FENG B B, CHEN D R, WANG J D, et al.Drag Reducing and Increasing Mechanism on Triangular Riblet Surface[J]. Journal of Nanjing University of Aeronautics & Astronautics (English Edition), 2014, 31(1): 78-84.
[27] 封贝贝, 陈大融, 汪家道. 亚音速飞行器壁面沟槽减阻研究与应用[J]. 清华大学学报(自然科学版), 2012, 52(7): 967-972.
FENG B B, CHEN D R, WANG J D.Riblet Surface Drag Reduction on Subsonic Aircraft[J]. Journal of Tsinghua University (Science and Technology), 2012, 52(7): 967-972.
[28] LIU Z M.Drag Reduction Performance of Triangular (V-Groove) Riblets with Different Adjacent Height Ratios[J]. Journal of Applied Fluid Mechanics, 2023, 16(4): 671-684.
[29] 康凯, 王国付, 耿孝恒, 等. 不同肋壁夹角下肋条湍流数值模拟研究[J]. 工程热物理学报, 2022, 43(4): 960-966.
KANG K, WANG G F, GENG X H, et al.Numerical Simulations on the Turbulent Flows of Riblets with Different Riblet Angles[J]. Journal of Engineering Thermophysics, 2022, 43(4): 960-966.
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