Results 11 to 20 of about 177 (133)
Effect of Riblets Geometry on Drag Reduction [PDF]
Engineering and Technology Journal, 2010 The effect of longitudinal riblet surface models (U, V and semi-Circular and U with fillet corner riblets) on the performance of unsymmetrical airfoil (NACA23015) which has been investigated numerically and experimentally. Numerical investigation involve
Nibras M. Mahdi, Ikhlase M. Fayed
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Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2011 The interaction of the overlying turbulent flow with riblets, and its impact on their drag reduction properties are analysed. In the so-called viscous regime of vanishing riblet spacing, the drag reduction is proportional to the riblet size, but for larger riblets the proportionality breaks down, and the drag reduction eventually ...
García Mayoral, Ricardo +1 more
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Direct numerical simulation of turbulent flow above zigzag riblets
AIP Advances, 2018 We investigate the drag-reducing performance of a zigzag riblet inspired by the “Miura fold” and its influence on the streamwise vortices above a wall-bounded turbulent flow through direct numerical simulations of channel flows. The employed channel wall
Kie Okabayashi +3 more
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Direct numerical simulation for modification of sinusoidal riblets
Journal of Fluid Science and Technology, 2016 This paper proposes a new riblet configuration. A traditional sinusoidal riblet was modified with the aim of reducing pressure drag. The height of the side wall in the newly configured riblet is lowered toward the node of the sinusoidal curve to reduce ...
Kie OKABAYASHI
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Frontiers in Bioengineering and Biotechnology, 2022 The aim of this study was to reveal potential relationship between the main flow field around a shortfin mako shark and the surface morphology of shark skin.
Chengchun Zhang +8 more
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Turbulent structure effects due to ordered surface roughness
Alexandria Engineering Journal, 2020 The effects of ordered surface feature in the form of converging-diverging riblets are investigated experimentally on an airfoil. Riblet sheets are applied onto the surface of NACA 0026 airfoil at a yaw angle of α=0°,±10°, Riblet height of h = 1 mm, and ...
Zambri Harun +3 more
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International Journal of Thermofluids, 2022 In this paper the flow characteristics and velocity fields over the vertical axis wind turbines DU 06 W 200 airfoil developed by Delft University of Technology and some other innovative designs are examined by computational fluid dynamics (CFD ...
Omid Ali Zargar +6 more
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Riblet Drag Reduction Modeling and Simulation
Fluids, 2022 One of the most interesting passive drag reduction techniques is based on the use of riblets or streamwise grooved surfaces. Detailed flow features inside the grooves can be numerically detected only by Direct Numerical Simulations (DNS), still ...
Benedetto Mele
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Direct numerical simulation for investigation on yaw angle effects on riblets
Journal of Fluid Science and Technology, 2017 The yaw angle (φ) effect on riblets are investigated by parametrically conducted direct numerical simulation (DNS). Three configurations are adopted: standard straight riblet, sinusoidal riblet, and modified sinusoidal riblet. The height of the side wall
Kie OKABAYASHI
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International Journal of Thermofluids, 2021 Turbulence and heat transfer are two critical factors in the chain of world energy consumption. Hence, development of more efficient energy transfer techniques in engineering applications through control and optimization of the thermal turbulent boundary
Shima Soleimani, Steven Eckels
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