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Turbulence structure manipulation in a channel flow by outer layer devices

Published online by Cambridge University Press:  04 July 2016

G. Iuso
G. Iuso*
Affiliation:
Dipartimento di Ingegneria Aeronautica, Politecnico di Torino, 10129 Torino, Italy
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Abstract

An experimental study has been performed manipulating a fully developed turbulent channel flow, by means of blade manipulators known as outer layer devices (Olds). A large amount of investigation has been performed for boundary layer flow, whereas little research is available for internal flow manipulation. The influence on drag reduction for different configurations (single and tandem) and for some geometric parameters (distance from the wall and blade gap), have been analysed. Reynolds number effect has also been investigated. Some of the mechanisms involved in the skin friction reduction process are examined, in terms of time-space integral scales, Reynolds stresses and spectral analysis. Results show better efficiency for tandem configurations. These give high local skin friction reductions, up to 20%, which are strongly dependent on the manipulator distance from the wall, but have very little dependence on the blade gap and Reynolds number. Turbulence analysis displays reduced fluctuations in all three directions — as with space-time integral scales. Evidence of suppression for the large structures is also shown by spectral analysis. From a global balance it has been verified that no net drag reduction is obtained due to the additional drag introduced by the manipulators.

Type
Research Article
Information
The Aeronautical Journal , Volume 98 , Issue 980 , December 1994 , pp. 388 - 394
Copyright
Copyright © Royal Aeronautical Society 1992 

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References

1. Andrew, S.W. Aircraft drag reduction technology, Agard CP-365, May 1984.Google Scholar
2. Bushnell, D.M. Turbulent drag reduction for external flow, Agard R-723, May 1985.Google Scholar
3. Kline, S.J., Reynolds, W.C., Schraub, F.A. and Runstadler, P.W. The structure of turbulent boundary layer, J Fluid Mech, 1967, 30, pp 741–733.Google Scholar
4. Blackwelder, R.F. The eddy structures in bounded shear flows, Agard Report 786, Special course on skin friction drag reduction, March 1994, VKI - Bruxelles.Google Scholar
5. Prabhu, A., Kailas, N., Kullkarni, R.S. and Narashima, R. Blade manipulators in channel flows, In: Proc IUTAM Symp Turbulence Management and Relaminarisation, Bangalore, Springer, 1987, p 97.Google Scholar
6. Pollard, A., Savill, A.M. and Thomann, H. Turbulent pipe flow manipulation: some experimental and computational results for single manipulator rings, Appl Sci Res, 1989, Special Volume 46, (3).Google Scholar
7. Pollard, A., Savill, A.M. and Thomann, H. Turbulent pipe flow manipulation: some experimantal and computational results for tandem rings, In: Proc. 10th Australian Fluid Mechanics Conference, pp 9-31.Google Scholar
8. Nguyen, V.D. and Dickinson, J. Some observations of static pressure distributions in pipe flow perturbeted by a LEBU ring, ERCOFTAC Bulletin 4, 1989.Google Scholar
9. Mah, Y.A., Khoo, B.C. and Chew, Y.T. Blade manipulators in fully developed turbulent flow, In: Proc Joint ASME/JSME Conf, Portland, 1991.Google Scholar
10. Khoo, B.C., Chew, Y.T. and Mah, Y.A. Skin friction following BLADE manipulation in a turbulent pipe flow, Exp Fluids, 1993, 15, pp 274–278.Google Scholar
11. Van Den Berg, B European meeting on turbulent drag reduction, NLR Report MP 860606, Lausanne, 1986.Google Scholar
12. Pollard, A., Thomann, H. and Savill, A.M. Manipulation and modelling of turbulent pipe flow: some parametric studies of single and tandem ring devices, In: Proc 4th European turbulent drag reduction working meeting, Lausanne, 1989.Google Scholar
13. Kline, H. and Friedrich, R. Large eddy simulation of manipulated boundary layer and channel flow, In: Proc. 4th European turbulence drag reduction working meeting, Lausanne, 1989.Google Scholar
14. Savill, A.M., Kline, H. and Friedrich, R. Pattern recognition analysis of structure in manipulated channel flow simulations, J Turbulence, 1994,1,(1).Google Scholar
15. Vasudevan, B., Prabhu, A., Narashima, R. Blade manipulators in turbulent channel flow, Exp Fluids, 1994,12, pp 200–208.Google Scholar
16. Savill, A.M. and Mumford, J.C. Manipulation of turbulent boundary layers by outer flow devices: skin friction and visualization results, J Fluid Mech, 1988,191,pp 89–418.Google Scholar
17. Corke, T.C.A. A New View on Origin, Role, and Manipulation of Large Scales in Turbulent Boundary Layers, PhD. Thesis, Illinois Inst of Technology, Chicago, IL, December 1981.Google Scholar