Results 171 to 180 of about 3,774 (202)

Secondary flow induced by riblets

Journal of Fluid Mechanics, 1998
The effects of riblets on one wall of a channel bounding fully developed turbulent flow are investigated. Various perturbation elements including wires, fins and slots are modelled in order to understand the effects of riblets. It is found that widely spaced riblets, fins and wires create a substantial increase in turbulent activity just above ...
Goldstein, D. B., Tuan, T.-C.
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Natural Low-Frequency Riblets

Flow, Turbulence and Combustion, 1998
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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The Influence of Process Parameters on the Forming of Riblets during Riblet Rolling

Key Engineering Materials, 2014
In aeronautics, economic and environmental aspects become increasingly important. As those are very much influenced by the frictional drag of the airplane, a reduction of skin friction which causes a major portion of total aerodynamic drag is desirable.
Julia Pöplau, Sebastian Stille, Thijs Romans, Tilmann Beck, Lorenz Singheiser, Gerhard Hirt   +5 more
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Riblet drag at flight conditions

Journal of Aircraft, 1989
This paper describes perforated and nonperforated riblet tests on the fuselage of a modified Learjet model 28/29 twin-engine business jet at Reynolds numbers of 1.0-2.75 x 10/ft and Mach numbers of 0.3-0.7. Drag reductions of the order of 6% at nondimensional wall spacings of 12 were obtained using boundary-layer rakes and direct drag balances.
Michael J. Walsh, William L. Sellers, Catherine B. McGinley   +2 more
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Laminar boundary layer over riblets

Physics of Fluids, 1994
Laser doppler anemometry (LDA) measurements and numerical calculations have been made for a laminar boundary layer on triangular riblets. Calculated mean velocity distributions along the riblet contour are in good agreement with the measured ones. The results show that no transversal motion exists above and within the riblet valleys (e.g., no secondary
L. Djenidi, F. Anselmet, J. Liandrat, L. Fulachier   +3 more
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Low Air Drag Surface via Multilayer Hierarchical Riblets

ACS Applied Materials & Interfaces, 2021
Riblets inspired by shark skin exhibit a great air drag reduction potential in many industries, such as the aircraft, energy, and transportation industries. Many studies have reported that blade riblets attain the highest air drag reduction ability, with a current limit of ∼11%.
ZiDan Zhou, ShengKun Wang, ZeXiang Yan, DaoYuan Wang, JinJun Deng, Yang He, WeiZheng Yuan   +6 more
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Drag Reduction With Superhydrophobic Riblets

Volume 8: Mechanics of Solids, Structures and Fluids, 2012
Samples combining riblets and superhydrophobic surfaces are fabricated at University of Pittsburgh and their drag reduction properties are studied at the Center for Nanophase Materials Sciences (CNMS) in Oak Ridge National Laboratory with a commercial cone-and-plate rheometer. In parallel to the experiments, numerical simulations are performed in order
Charlotte Barbier, Elliot Jenner, Brian D’Urso   +2 more
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Yaw Angle Effects on Optimized Riblets

2001
The drag reducing effect of riblets, has been demonstrated previously both experimentally and theoretically. Several aspects of the application of riblet film on an long range aircraft are considered. The aim of the present investigation is to check experimentally the effects of an angle of yaw on the performance of riblets.
Hage, W., Bechert, D. W., Bruse, M.
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On Riblet's Theorem (Correspondence)

IEEE Transactions on Microwave Theory and Techniques, 1958
Riblet presented the following theorem which is concerned with the synthesis of a quarter-wave impedance transformer.
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Smart Flow Control with Riblets

Advanced Materials Research, 2013
A review of riblets as a smart flow control device is given. After the state-of-the-art examination of the drag reduction performance, different views on the drag reduction mechanism are put in perspective. Being a smart flow control device, riblets can control not only momentum, but also heat and flow noise.
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