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Conditionally sampled measurements near the outer edge of a turbulent boundary layer

Published online by Cambridge University Press:  29 March 2006

R. A. Antonia
R. A. Antonia
Affiliation:
Department of Mechanical Engineering, The University of Sydney
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Abstract

The conditional sampling technique is used to measure ensemble averages of the longitudinal and normal velocity fluctuations u and v respectively and of the Reynolds shear stress fluctuations uv both within the turbulent and irrotational regions near the outer edge of a turbulent boundary layer. The measurements are made in both a smooth- and a rough-wall boundary layer under zero-pressure-gradient conditions. The smooth- and rough-wall results are qualitatively similar but the magnitude of the rough-wall averages is higher than that of the smooth- wall averages, corresponding with the higher value of wall shear stress on the rough surface. The maximum shear stress value encountered within a burst represents a significant proportion of the wall shear stress.

The statistical properties of the turbulence within the burst are close but not quite identical to the nearly Gaussian properties of the inner region of the boundary layer. During an attempt to distinguish between bursts of different ages or strengths at the time of measurement, it was found that bursts of relatively short duration travel at much the same longitudinal velocity as the local mean U and contribute little to the local shear stress. The longer and less frequent bursts have a mean velocity smaller than U and a maximum shear stress comparable to the shear stress at the wall.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 56 , Issue 1 , 14 November 1972 , pp. 1 - 18
Copyright
© 1972 Cambridge University Press

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References

Antonia, R. A. 1971 Dept. Mech. Engng, University of Sydney, Charles Kolling Res. Lab. Tech. Note, F-29.
Antonia, R. A. & Bradsraw, P. 1971 Imperial College Aero. Rep. no. 71-04.
Antonia, R. A. & Luxton, R. E. 1971a J. Fluid Mech. 48, 721.
Antoma, R. A. & Luxton, R. E. 1971b Dept. Mech. Engng, University of Sydney, Charles Kolling Res. Lab. Tech. Note, F-31.
Corrsin, S & Kistler, A. L. 1955 N.A.C.A. Rep. no. 1244.
Fiedler, H. & Head, M. R. 1966 J. Fluid Mech. 25, 719.
Fraser, D. 1969 Dept. Mech. Engng, University of Sydney, Charles Kolling Res. Lab. Tech. Note, F-9.
Grant, H. L. 1958 J. Fluid Mech. 4, 149.
Imaei, K. 1968 Bull. Inst. Space Aeronaut. Sci., University of Tokyo, 4, 448 (in Japanese only).
Kaplan, R. E. & Laufer, J. 1969 Proceedings of the 12th International Congress on Applied Mechanics, p. 236. Springer.
Kim, H. T., Kline, S. J. & Reynolds, W. C. 1968 Stanford University, Dept. Mech. Engng Rep. MD-20.
Klebanoff, P. S. 1955 N.A.C.A. Rep. no. 1247.
Kline, S. J., Reynolds, W. C., Schraub, F. A. & Runstadler, P. W. 1967 J. Fluid Mech. 30, 741.
Kovasznay, L. S. G. 1970 Ann. Rev. Fluid Mech. 2, 95.
Kovasznay, L. S. G., Kibens, V. & Blackwelder, R. F. 1970 J. Fluid Mech. 41, 283.
Liu, C. K., Line, S. J. & Johnston, J. P. 1966 Stanford University, Dept. Mech. Engng Rep. MD-15.
Rotta, J. C. 1956 Ing. Arch. 24, 258.
Townsend, A. A. 1949 Aust. J. Sci. Res. 2, 451.
Townsend, A. A. 1956 The Structure of Turbulent Shear Flow. Cambridge University Press.
Wygnanski, I. 1971 Israel J. Tech. 9, 105.
Wygnanski, I. & Fiedler, H. E. 1969 J. Fluid Mech. 38, 577.
Wygnanski, I. & Fiedler, H. E. 1970 J. Fluid Mech. 41, 327.