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Drag reduction in a rectangular duct usingriblets

Published online by Cambridge University Press:  04 July 2016

A. R. Moore
Affiliation:
Department of Aerospace EngineeringUniversity of Bristol, Bristol, UK
M. V. Lowson
Affiliation:
Department of Aerospace EngineeringUniversity of Bristol, Bristol, UK

Abstract

An experimental investigation has been made into theeffects of riblets on the drag in a rectangular ductof aspect ratio 10. It has been found that a maximumdrag reduction of approximately 10% occurs in fullydeveloped turbulent flow. This figure is larger thanthe 6–8% drag reduction usually found for externalflow. The maximum drag reduction occurred when theheight of the riblets was between 7 and 13 wallunits. Analysis of the developing region of the flowhas shown a maximum drag reduction of approximately8% at a wall unit value of 13, consistent withresults in external flows. The effects of riblets ontransition has also been investigated. It was foundthat riblets delayed transition by 2–4% in criticalRe as measured by peak flatness, and caused someextension in the length of the transition process,so that the completion of transition was delayed bybetween 4–8%, with the stronger effect at the lowerReynolds numbers.

Information

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1995 

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References

1. Walsh, M.J. Turbulent boundary layer drag reduction using riblets, AIAA Paper 82–0169, 1982.Google Scholar
2. Walsh, M.J. Riblets as a viscous drag reduction technique, AIAA J, 21, pp 485486.Google Scholar
3. Walsh, M.J. and Lindemann, A.M. Optimisation and application of riblets for turbulent drag reduction, AMA Paper 84–0347, 1984.Google Scholar
4. Liu, K.N., Christodoulou, C., Riccius, O. and Joseph, D.D. Drag reduction in pipes lined with riblets, AIAA J, 28, (10), pp 16971698.Google Scholar
5. Nitschke, P. Experimental investigation of the turbulent flow in smooth and longitudinal grooved pipes, NASA TM-77480, 1984.Google Scholar
6. Lowson, M.V., Jewson, A.H. and Bates, J.H.D. Drag reduction by riblets in a two-dimensional duct, Section 4.1, Drag Reduction in Fluid Flows, Sellin, R.H.J, and Moses, R.T. (Eds), Ellis Horwood, 1989.Google Scholar
7. Rohr, J., Anderson, G.W. and Reidy, L.W. An experimental investigation of the drag reduction effects of riblets in pipes, Drag Reduction in Fluid Flows, Sellin, R.H.J, and Moses, R.T. (Eds), Ellis Horwood, 1989, pp 263270.Google Scholar
8. Newmann, D. and Dinkelacker, A. Drag reduction by longitudinal riblets on the surface of a streamwise aligned body of revolution, Drag Reduction in Fluid Flows, Sellin, R.H.J, and Moses, R.T. (Eds), Ellis Horwood, 1989, pp 9398.Google Scholar
9. Kodov, V.E., Kuznetsov, V.R., Mineev, B.I. and Secundov, A.N. The influence of Free Stream Turbulence and Surface Ribbing on the Characteristics of Transitional Boundary Layers, In: Proceedings International Symposium on Near Wall Turbulence Dubrovnik, 1988.Google Scholar
10. Chen, J.J.J., Leung, Y.C. and Ko, N.M.W. Flow in Grooved Channels, In: Proceedings 9th Australasian Fluid Mechanics Conference Auckland, December 1986.Google Scholar
11. Chu, D.C. A Direct Simulation of Laminar and Turbulent Flows Over Streamwise Aligned Riblets, PhD Thesis, Princeton, 1992.Google Scholar
12. Ladd, D.M., Rohr, J.J., Reidy, L.W. and Hendricks, E.W. The effects of riblets on laminar to turbulent transition, Experiments in Fluids, 1993, 14, pp 19.Google Scholar