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Modification of large eddies in turbulent boundary layers

Published online by Cambridge University Press:  26 April 2006

Shi-Ing Chang
Affiliation:
Department of Aerospace Engineering, University of Southern California, Los Angeles, CA 90089-1191, USA
Ron F. Blackwelder
Affiliation:
Department of Aerospace Engineering, University of Southern California, Los Angeles, CA 90089-1191, USA

Abstract

Turbulent boundary layers were altered with a tandem array of manipulators arranged to produce a maximum drag reduction. The Reynolds number based on the momentum thickness, Reθ, at the first manipulator position was between 1700 and 2400. Temperature was used as a passive contaminant to explore the dynamical relationship between the near-wall and outer regions of the manipulated layer. Heat was introduced by warming the wall uniformly to 15°C above the ambient temperature or with a line heater in the wake of the manipulator. Temperature and velocity measurements showed a reduction in fluctuation amplitude and a strong decrease in larger scale mixing accompanied by a reduction of the Taylor microscale and integral lengthscale. Isocorrelations indicated that the eddy size was decreased in all three directions. The net result of the manipulators was a marked decrease in the entrainment of irrotational fluid into the boundary layer. The results suggest that the manipulators do not directly affect the wall region but rather decrease the entrainment, and hence the growth of the boundary layer, leading to possible drag reduction.

Type
Research Article
Copyright
© 1990 Cambridge University Press

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References

Anders, J. B. 1985 Aerospace Technology Conference and Exposition, Long Beach, California, SAE Tech. Paper Series 861769.
Anders, J. B. 1989 AIAA-89–1011.
Antonia, R. A., Browne, L. W. B. & Chambers, A. J. 1981 Rev. Sci. Instrum. 52, 1382.
Antonia, R. A., Danh, H. Q. & Prabhu, A. 1977 J. Fluid Mech. 80, 153.
Blackwelder, R. F. & Chang, S.-I. 1986 AIAA-86–0287.
Blackwelder, R. F. & Haritonidis, H. 1983 J. Fluid Mech. 132, 87.
Blackwelder, R. F. & Kaplan, R. E. 1976 J. Fluid Mech. 76, 89.
Bonnet, J. P., Delville, J. & Lemay, J. 1987 In Proc. RAeS Intl Conf. Turbulent Drag Reduction by Passive Means, London, pp. 45.
Champagne, F. H. 1978 In Dynamics Measurements in Unsteady Flows (ed. L. S. G. Kovasznay), p. 101. Dynamic Flow Conference, Skovlunde, Denmark.
Chang, S.-I. 1987 Modification of large eddies in a turbulent boundary layer. Ph.D. dissertation, University of Southern California.
Chen, C.-H. P. 1975 The large scale motion in a turbulent boundary layer. Ph.D. dissertation, University of Southern California.
Chen, C.-H. P. & Blackwelder, R. F. 1978 J. Fluid Mech. 89, 1.
Coles, D. 1968 In Proc. Computation of Turbulent Boundary Layer, Vol. 1, p. 1. Stanford Conference.
Corke, T. C., Guezennec, Y. & Nagib, H. M. 1980 In Proc. Viscous Drag Reduction Symposium, Dallas. AIAA, Vol. 72, p. 128.
Corrsin, S. 1949 NACA Tech. Note 1864.
Corrsin, S. & Kistler, A. L. 1955 NACA Rep. 1244.
Coustols, E., Cousteix, J. & Belanger, J. 1987 In Proc. RAeS Intl Conf. Turbulent Drag Reduction by Passive Means, London, pp. 250.
Fiedler, H. 1978 In Dynamics Measurements in Unsteady Flows (ed. L. S. G. Kovasznay), p. 81. Dynamic Flow Conference, Skovlunde, Denmark.
Guezennec, Y. G. & Nagib, H. M. 1985 AIAA-85–0519.
Gutmark, E. & Blackwelder, R. F. 1987 Exp. Fluids 5, 217.
Hedley, T. B. & Keffer, J. F. 1974a J. Fluid Mech. 64, 625.
Hedley, T. B. & Keffer, J. F. 1974b J. Fluid Mech. 64, 645.
Kovasznay, L. S. G., Kibens, V. & Blackwelder, R. F. 1970 J. Fluid Mech. 41, 283.
Larue, J. C. 1974 Phys. Fluids 17, 1513.
Lemay, J., Provencal, D., Gourdeau, R., Nguyen, V. D. & Dickinson, J. 1985 AIAA-85–0521.
Lemay, J., Savill, A. M., Bonnet, J.-P. & Delville, J. 1987 In Proc. 6th Turbulent Shear Flows Symposium, Toulouse. Springer.
Plesniak, M. W. & Nabig, H. M. 1985 AIAA-85–0518.
Prabhu, A., Vasudevan, B., Kailasnath, P. K., Kulkarni, R. S. & Narasimha, R. 1988 Turbulence Management and Relaminerization, Heidelberg, pp. 97. Springer.
Sato, H. & Kuriki, K. 1961 J. Fluid Mech. 11, 321.
Savill, A. M. & Mumford, J. C. 1988 J. Fluid Mech. 191, 389.
Savill, A. M., Truong, T. V. & Ryhming, I. L. 1988 J. Mëc. Théor. Appl. 7, 353.
Schubauer, G. B. & Skramstad, H. K. 1948 NACA Rep. 909.
Spalding, D. B. 1961 Trans. ASME E: J. Appl. Mech. 28, 455.Google Scholar
Subramanian, C. S. & Antonia, R. A. 1981 Intl J. Heat Mass Transfer 24, 1833.
Thomas, R. M. 1973 J. Fluid Mech. 57, 549.
Westphal, R. V. 1986 AIAA-86–0283.