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The structure of a separating turbulent boundary layer. Part 2. Higher-order turbulence results

Published online by Cambridge University Press:  20 April 2006

Roger L. Simpson ,
Y.-T. Chew  and
B. G. Shivaprasad
Roger L. Simpson
Affiliation:
Southern Methodist University, Dallas, Texas 75275
Y.-T. Chew
Affiliation:
Southern Methodist University, Dallas, Texas 75275 Present address: Department of Mechanical and Production Engineering, University of Singapore.
B. G. Shivaprasad
Affiliation:
Southern Methodist University, Dallas, Texas 75275
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Abstract

The velocity-probability-distribution flatness and skewness factors for u and v are reported for the separating turbulent boundary layer described by Simpson, Chew & Shivaprasad (1981). Downstream of separation the skewness factor for u is negative near the wall, whereas it is positive upstream of separation. The flatness factor for u downstream of separation differs from the upstream behaviour in that it has a local maximum of about 4 at the minimum mean velocity location in the backflow. Both upstream and downstream of separation the skewness factor for v has a profile shape and magnitudes that are approximately the mirror image or negative of the skewness factor for u. The flatness factor for v seems to be affected little by separation.

Examination of the momentum and turbulence-energy equations reveals that the effects of normal stresses are important in a separating boundary layer. Negligible turbulence-energy production occurs in the backflow. Turbulence-energy diffusion is increasingly significant as separation is approached and is the mechanism for supplying turbulence energy to the backflow.

The backflow appears to be controlled by the large-scale eddies in the outer region flow, which provides the mechanism for turbulence-energy diffusion. The backflow behaviour does not appear to be significantly dependent on the far downstream near-wall conditions when the thickness of the backflow region is small compared with the turbulent shear layer thickness.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 113 , December 1981 , pp. 53 - 73
Copyright
© 1981 Cambridge University Press

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References

Antonia, R. A. 1973 Phys. Fluids 16, 1198–1206.
Bradshaw, P. 1967 J. Fluid Mech. 29, 625–645.
Dumas, R. & Marcillat, J. 1966 C. R. Acad. Sci. Paris A 262, 700–703.
East, L. F. & Sawyer, W. G. 1979 Proc. NATO-AGARD Fluid Dynamics Symp.
Eckelmann, H. 1974 J. Fluid Mech. 65, 439–459.
Fox, R. W. & Kline, S. J. 1962 Trans. A.S.M.E. D, J. Basic Engng. 84, 303–312.
Kreplin, H.-P. 1973 M.Sc. thesis, Max-Planck-Institut für Strömungsforchung, Göttingen.
Perry, A. E. & Schofield, W. H. 1973 Phys. Fluids 16, 2068–2074.
Rotta, J. C. 1962 Prog. Aeron. Sci. 2, 1–219.
Sandborn, V. A. 1959 J. Fluid Mech. 6, 221–240.
Shiloh, K., Shivaprasad, B. G. & Simpson, R. L. 1981 J. Fluid Mech. 113, 75–90.
Simpson, R. L. & Chew, Y.-T. 1979 Proc. of 3rd Int. Workshop on Laser Velocimetry, pp. 179–196. Hemisphere.
Simpson, R. L., Chew, Y.-T. & Shivaprasad, B. G. 1980 Project SQUID Rep. SMU-4-PU. (To appear as DTIC or NTIS Report.)
Simpson, R. L., Chew, Y.-T. & Shivaprasad, B. G. 1981 J. Fluid Mech. 113, 23–51.
Simpson, R. L. & Collins, M. A. 1978 A.I.A.A. J. 16, 289–290.
Simpson, R. L., Strickland, J. H. & Barr, P. W. 1977 J. Fluid Mech. 79, 553–594.
Spangenberg, W. G., Rowland, W. R. & Mease, N. E. 1967 Fluid Mechanics of Internal Flow (ed. G. Sovran), pp. 110–151. Elsevier.
Strickland, J. H. & Simpson, R. L. 1975 Phys. Fluids 18, 306–308.
Ueda, H. & Hinze, J. O. 1975 J. Fluid Mech. 67, 125–143.
Wygnanski, I. & Fiedler, H. E. 1970 J. Fluid Mech. 41, 327–361.
Zaric, Z. 1972 4th All-Union Heat and Mass Transfer Conf. Minsk, U.S.S.R.