Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-28T06:12:55.143Z Has data issue: false hasContentIssue false
  • English
  • Français

The structure of the large eddies in fully developed turbulent shear flows. Part 1. The plane jet

Published online by Cambridge University Press:  20 April 2006

J. C. Mumford
J. C. Mumford
Affiliation:
Fluid Dynamics Section, Cavendish Laboratory, Madingley Road, Cambridge, U.K.
Get access Rights & Permissions [Opens in a new window]

Abstract

A series of measurements, obtained using arrays of hot-wire anemometers, has been performed in the fully developed region of a plane turbulent jet. The anemometer output signals were simultaneously sampled, digitized with sufficient resolution for numerical linearization, and recorded on magnetic tape for subsequent analysis.

The data was processed to extract information about the structure of the large eddies within the flow. Firstly, a selection of the two-point velocity correlation functions was evaluated, and diagrams of the contours of constant correlation for the stream wise velocity component were constructed. Secondly, an iterative procedure similar to the techniques generally described as ‘pattern recognition and image enhancement’ was used to form ‘ensemble’ averages of the two-dimensional patterns of the streamwise velocity component associated with the large eddies.

The results indicate that the large eddies in the fully turbulent region of the flow are roller-like structures with axes aligned approximately either with the direction of the strain associated with the mean-velocity gradient or with the direction of homogeneity (spanwise). It was found that these basic structures tended to occur in various preferred combinations. Estimates were obtained for the total intensity contribution from the large eddies, the ranges of sizes and intensities of the individual structures, and their effective packing density.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 118 , May 1982 , pp. 241 - 268
Copyright
© 1982 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Blackwelder, R. F. 1979 Dynamic measurements in unsteady flows. In Proc. Dynamic Flow Conf. 1978, Marseilles and Baltimore, p. 173.
Bruun, H. H. 1971 J. Sci. Instrum. 4, 815.
Champagne, F. H., Sleicher, C. A. & Wehrmann, O. H. 1967 J. Fluid Mech. 28, 153.
Davies, P. O. A. L. & Yule, A. J. 1975 J. Fluid Mech. 69, 513.
Favre, A. J., Gaviglio, J. J. & Dumas, R. J. 1957 J. Fluid Mech. 2, 313.
Favre, A. J., Gaviglio, J. J. & Dumas, R. J. 1958 J. Fluid Mech. 3, 344.
Fisher, M. J. & Davies, P. O. A. L. 1964 J. Fluid Mech. 18, 97.
Grant, H. L. 1958 J. Fluid Mech. 4, 149.
Kovasznay, L. S. G., Kibens, V. & Blackwelder, R. F. 1970 J. Fluid Mech. 41, 283.
Lumley, J. L. 1965 Atmospheric turbulence and radio wave propagation. In Proc. Int. Colloq. Moscow, p. 166.
Mumford, J. C. 1973 Some properties of the plane turbulent jet. Ph.D. dissertation, University of Cambridge.
Payne, F. R. & Lumley, J. L. 1967 Phys. Fluids Suppl. 10, S194.
Sabot, J. & Comte-Bellot, G. 1973 J. Fluid Mech. 74, 767.
Sternberg, J. 1967 Phys. Fluids Suppl. 10, S146.
Townsend, A. A. 1970 J. Fluid Mech. 41, 13.
Townsend, A. A. 1976 The Structure of Turbulent Shear Flow. Cambridge University Press.
Townsend, A. A. 1979 J. Fluid Mech. 95, 515.
Tritton, D. J. 1967 J. Fluid Mech. 28, 439.
Wallace, J. M., Brodkey, R. S. & Eckelmann, H. 1977 J. Fluid Mech. 83, 673.
Wygnanski, I. & Fiedler, H. E. 1969 J. Fluid Mech. 38, 577.