Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-27T14:03:45.015Z Has data issue: false hasContentIssue false
  • English
  • Français

Properties of the large structure in a slightly heated turbulent mixing layer of a plane jet

Published online by Cambridge University Press:  20 April 2006

S. Rajagopalan  and
R. A. Antonia
S. Rajagopalan
Affiliation:
Department of Mechanical Engineering, University of Newcastle, N.S.W., 2308, Australia
R. A. Antonia
Affiliation:
Department of Mechanical Engineering, University of Newcastle, N.S.W., 2308, Australia
Get access Rights & Permissions [Opens in a new window]

Abstract

The convection speed and average inclination of the large structure in the turbulent mixing layer of a plane jet have been obtained using different techniques. Ensemble-averaged shapes of the signatures of velocity and temperature associated with this structure are also presented. An array of cold wires is used to simultaneously observe the temperature fluctuation θ at several points in space. A cold-wire/X-wire combination is used to measure θ, the streamwise u and the normal v velocity fluctuations. The front of the structure moves faster than the back and the average inclination of this structure to the jet axis is approximately 40°. A detection scheme, based on positive peaks of the cubed values of the temperature derivative, is used to identify the large structure and obtain average signatures of θ, u, v, and of the products uv, θ and vθ. These signatures are consistent with a vortex-like description of the large structure. They also reflect the existence of a thin interconnecting region or ‘braid’ between two consecutive vortical structures. This region is identified by the sharp changes in temperature and is interpreted as part of the large structure. In the central part of the mixing layer, at least 80% of the Reynolds shear stress and 50% of the average normal heat flux appear to be contributed by the large structure.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 105 , April 1981 , pp. 261 - 281
Copyright
© 1981 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. 1977 On the role of phase information in conditional sampling. Phys. Fluids Suppl. 20, 232.Google Scholar
Browand, F. K. 1975 Ensemble-averaged large scale structure in the turbulent mixing layer. Turbulent Mixing in Non-Reactive and Reactive Flows (ed. S. N. B. Murthy), p. 317. Plenum.
Browand, F. K. & Weidman, P. D. 1976 Large scales in developing mixing layer. J. Fluid Mech. 76, 217.Google Scholar
Brown, G. L. & Roshko, A. 1974 On density effects and large structure in turbulent mixing layers. J. Fluid Mech. 64, 775.Google Scholar
Bruun, H. H. 1977 A time-domain analysis of the large-scale flow structure in a circular jet. Part 1. Moderate Reynolds number. J. Fluid Mech. 83, 641.Google Scholar
Chen, C. P. & Blackwelder, R. F. 1978 Large-scale motion in a turbulent boundary layer: a study using temperature contamination. J. Fluid Mech. 89, 1.Google Scholar
Clark, A. R. & Hussain, A. K. M. F. 1979 On convection velocities in a mixing layer: effects of the initial condition. Proc. 2nd Symposium on Turbulent Shear Flows, p. 2.30. Imperial College, London.
Davies, P. O. A. L. & Yule, A. J. 1975 Coherent structures in turbulence. J. Fluid Mech. 69, 513.Google Scholar
Dean, R. B. & Bradshaw, P. 1976 Measurements of interacting turbulent shear layers in a duct. J. Fluid Mech. 78, 641.Google Scholar
Dimotakis, P. E. & Brown, G. L. 1976 The mixing layer at high Reynolds number: large structure dynamics and entrainment. J. Fluid Mech. 78, 535.Google Scholar
Fiedler, H. E. 1974 Transport of heat across a plane turbulent mixing layer. Adv. Geophys. A 18, 93.Google Scholar
Fiedler, H. E. 1975 On turbulence structure and mixing mechanism in free turbulent shear flows. Turbulent Mixing in Non-Reactive and Reactive Flows (ed. S. N. B. Murthy), p. 381. Plenum.
Gibson, C. H., Friehe, C. A. & McConnell, S. O. 1977 Structure of sheared turbulent fields. Phys. Fluids Suppl. 20, 156.Google Scholar
Hussain, A. K. M. F. & Clark, A. R. 1981 On the coherent structure of the axisymmetric mixing layer: a flow-visualization study. J. Fluid Mech. 104, 263.Google Scholar
Hussain, A. K. M. F. & Zaman, K. B. M. Q. 1980 Vortex pairing in a circular jet under controlled excitation. Part 2. Coherent structure dynamics. J. Fluid Mech. 101, 493.Google Scholar
Lau, J. C. & Fisher, M. J. 1975 The vortex-street structure of ‘turbulent’ jets. Part 1. J. Fluid Mech. 67, 299.Google Scholar
Oster, D., Wygnanski, I., Dziomba, B. & Fiedler, H. 1978 On the effect of initial conditions on the two dimensional turbulent mixing layer. Structure and Mechanisms of Turbulence I (ed. H. Fiedler), Lecture Notes in Physics, vol. 75, p. 48. Springer.
Rajagopalan, S. & Antonia, R. A. 1979 Interaction between large and small scale motions in a two-dimensional duct flow. Phys. Fluids 23, 1101.Google Scholar
Sokolov, M., Hussain, A. K. M. F. & Kleis, S. J. 1979 A spark-induced turbulent ‘spot’ in a turbulent mixing layer. Proc. 2nd Symp. on Turbulent Shear Flows, p. 11.13. Imperial College, London.
Sreenivasan, K. R. & Antonia, R. A. 1977 Skewness of temperature derivatives in turbulent shear flows. Phys. Fluids 20, 1986.Google Scholar
Sreenivasan, K. R., Antonia, R. A. & Britz, D. 1979 Local isotropy and large structures in a heated turbulent jet. J. Fluid Mech. 94, 745.Google Scholar
Sreenivasan, K. R. & Tavoularis, S. 1980 On the skewness of the temperature derivative in turbulent flows. J. Fluid Mech. 101, 783.Google Scholar
Subramanian, C. S. & Antonia, R. A. 1979 Some properties of the large scale structure in a slightly heated turbulent boundary layer. Proc. 2nd Symp. on Turbulent Shear Flows, p. 4.18. Imperial College, London.
Sunyach, M. 1971 Contribution à l’étude des frontières d’écoulements turbulents libres. Thèse Docteur ès Sciences, Université Claude Bernard, Lyon.
Winant, C. D. & Browand, F. K. 1974 Vortex pairing: the mechanism of turbulent mixing layer growth at high Reynolds number. J. Fluid Mech. 63, 237.Google Scholar
Wygnanski, I. 1979 The recognition of an evoked large-scale structure. Proc. Dynamic Flow Conf. - Dynamic Measurements in Unsteady Flows, 1978, p. 191. Baltimore, Marseille.
Wygnanski, I. & Fiedler, H. E. 1970 The two-dimensional mixing region. J. Fluid Mech. 41, 327.Google Scholar
Yule, A. J. 1978 Large-scale structure in the mixing layer of a round jet. J. Fluid Mech. 89, 413.Google Scholar