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Effect of free-stream turbulence on large structure in turbulent mixing layers

Published online by Cambridge University Press:  12 April 2006

C. Chandrsuda ,
R. D. Mehta ,
A. D. Weir  and
P. Bradshaw
C. Chandrsuda
Affiliation:
Department of Aeronautics, Imperial College, London Present address: Royal Thai Air Force Academy, Bangkok, Thailand.
R. D. Mehta
Affiliation:
Department of Aeronautics, Imperial College, London
A. D. Weir
Affiliation:
Department of Aeronautics, Imperial College, London Present address: University of the South Pacific, Suva, Fiji.
P. Bradshaw
Affiliation:
Department of Aeronautics, Imperial College, London
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Abstract

Flow-visualization investigations and correlation measurements show that the essentially two-dimensional structures which dominated the turbulent mixing layer of Brown & Roshko (1974) are formed only if the free-stream turbulence is low. If free-stream disturbances are significant, as is likely in most practical cases, including a mixing layer entraining ‘still air’ from the surroundings, three-dimensionality develops at an early stage in transition. Other recent experiments strongly suggest that the Brown-Roshko structure will not form if the initial mixing layer is turbulent or subject to instability modes other than spanwise vortices. Therefore the Brown-Roshko structure will be rare in practice. The alternative large structure in a mixing layer, found by several workers, is intense, but fully three-dimensional and thus less orderly than the Brown-Roshko structure.

The balance of evidence suggests that if the Brown-Roshko structure does appear it will eventually relax into the alternative fully three-dimensional form: the Kármán vortex street behind a bluff body provides a precedent for slow development of three-dimensionality. However the Brown-Roshko structure, if formed, may well relax so slowly as to be identifiable for the full length of a practical flow.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 85 , Issue 4 , 27 April 1978 , pp. 693 - 704
Copyright
© 1978 Cambridge University Press

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References

Batt, R. G. 1975 A.I.A.A. J. 13, 245.
Benney, D. 1961 J. Fluid Mech. 10, 209.
Bilanin, A. J., Teske, M. E., Donaldson, C. DUP. & Snedeker, R. S. 1976 N.A.S.A. Symp. Wake Vortex Minimization, Wash., p. 55.
Birch, S. F. 1977a In Turbulence in Internal Flows (ed. S. N. B. Murthy), p. 89. Hemisphere.
Birch, S. F. 1977b Paper presented at Penn. State Univ. Symp. Turbulent Shear Flow.Google Scholar
Bradshaw, P. 1966 J. Fluid Mech. 26, 225.
Bradshaw, P. 1975 In Turbulent Mixing in Nonreactive and Reactive Flows (ed. S. N. B. Murthy), p. 243. Plenum.
Bradshaw, P., Ferriss, D. H. & Johnson, R. F. 1964 J. Fluid Mech. 19, 591.
Brown, G. L. & Roshko, A. 1974 J. Fluid Mech. 64, 775.
Castro, I. P. & Bradshaw, P. 1975 J. Fluid Mech. 73, 265.
Champagne, F. H., Pao, Y. H. & Wygnanski, I. J. 1976 J. Fluid Mech. 74, 209.
Chandrsuda, C. & Bradshaw, P. 1975 Imp. Coll. Aero. Rep. no. 75–03.
Crow, S. C. & Champagne, F. H. 1971 J. Fluid Mech. 48, 547.
Dimotakis, P. E. & Brown, G. L. 1976 J. Fluid Mech. 78, 535.
Grant, H. L. 1958 J. Fluid Mech. 4, 149.
Hill, W. G., Jenkins, R. C. & Gilbert, B. L. 1976 A.I.A.A. J. 14, 1513.
Jiminez, J. 1975 Phys. Fluids 18, 1580.
Johnston, J. P., Halleen, R. M. & Lezius, D. K. 1972 J. Fluid Mech. 56, 533.
Jones, B. J., Planchon, H. P. & Hammersley, R. J. 1973 A.I.A.A. J. 11, 1146.
LAM Kit 1977 M.Phil. thesis, Mech. Engng Dept., University of Hong Kong.
Liepmann, H. W. & Laufer, J. 1947 N.A.C.A. Tech. Note no. 1257.
Oster, D., Wygnanski, I. & Fiedler, H. 1977 In Turbulence in the Internal Flows (ed. S. N. B. Murthy), p. 67. Hemisphere.
Pui, N. K. & Gartshore, I. S. 1977 Paper presented at 6th Can. Cong. Appl. Mech.
Rockwell, D. O. 1977 J. Fluid Engng 99, 240.
Rodi, W. 1975 In Studies in Convection (ed. B. E. Launder), vol. 1, p. 79. Academic Press.
Sabin, C. M. 1963 Thermosci. Div., Stanford Univ. Rep. MD-9.
Weber, D. P. 1974 Ph.D. thesis, University of Illinois at Urbana Champaign.
Widnall, S. & Sullivan, J. P. 1973 Proc. Roy. Soc. A 332, 335.
Wille, R. 1963 Z. Flugwiss. 11, 222.
Winant, C. D. & Browand, F. K. 1974 J. Fluid Mech. 63, 2.
Yule, A. 1977 Submitted to J. Fluid Mech.Google Scholar