Results 131 to 140 of about 384 (179)

Natural Low-Frequency Riblets

Flow, Turbulence and Combustion, 1998
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The effect of riblets on sails

Experiments in Fluids, 1995
This paper describes an experimental investigation into the effect of riblets on the aerodynamic forces generated by sails. Riblets are known to reduce the viscous drag on flat surfaces and on airfoils, but their effect on the drag — or on the lift — of a highly three-dimensional, very thin lifting surface such as a sail is unknown.
A. E. Alving, P. Freeberg
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Drag Reduction in Pipes Lined with Riblets

AIAA Journal, 1990
In the present paper, experiments are reported establishing a maximum drag reduction of five to seven percent in fully developed turbulent flow of water through 25.4mm and 50.8mm diameter pipes lined with a film of grooved equilateral triangles of base 0.11mm. The maximum reduction occurs when the height of the riblets is 11 to 16 wall units.
K. N. Liu, C. Christodoulou, O. Riccius, D. D. Joseph   +3 more
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On riblets in laminar flows

1989
Riblets are little groves dug on the surface of flying or swimming solid bodies in order to reduce their drag. Why riblets work is not known but it is believed that it is a turbulent process because they trap the main eddies that develop near the solid body surfaces.
O. Pironneau, G. Arumugam
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Grinding of Riblets on Curved Paths

Materials Science Forum, 2016
The grinding of riblets with multiple profiled grinding wheels is an efficient method to minimize the fluid friction on surfaces. In turbo machinery components, like pump impellers or compressor blades, the riblets must be ground with a curved tool path since the flow is rarely linear on such surfaces.
Berend Denkena, Thilo Grove, Jan Harmes
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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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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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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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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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Heat transfer study of riblets

1991
A wind tunnel study of the heat-transfer characteristics of surfaces with triangular profile riblets has been carried out in a two-dimensional turbulent boundary layer and the results compared with those of a smooth surface. The heat-transfer coefficient has been measured for the Reynolds number of 2.8 to 11.3×105 based on the streamwise length ...
K.-S. Choi, S. Hamid
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