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On the pairing process in an excited plane turbulent mixing layer

Published online by Cambridge University Press:  21 April 2006

I. Wygnanski  and
I. Weisbrot
I. Wygnanski
Affiliation:
Faculty of Engineering, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA.
I. Weisbrot
Affiliation:
Faculty of Engineering, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel
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Abstract

The flow field in a plane, turbulent mixing layer disturbed by a small oscillating flap was investigated. Three experiments were carried out: one in which the flap oscillated sinusoidally at a single frequency: a second in which the flap oscillated at two frequencies, a fundamental and a subharmonic, but the ensuing motion was dominated by the fundamental perturbation; and a third in which the amplitude of the subharmonic perturbation was increased until a distortion in the mean flow was noticeable. Two velocity components were measured at all phase angles relative to the subharmonic oscillation of the flap at densely spaced intervals. The data were used to map the phase-locked spanwise vorticity component and the phase-locked streakline patterns for the purpose of assessing the relevance of the latter to the understanding of the dynamical process involved.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 195 , October 1988 , pp. 161 - 173
Copyright
© 1988 Cambridge University Press

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References

Browand, F. K. & Ho C. M. 1983 The mixing layer: an example of quasi two-dimensional turbulence. J. Méc. Théor. Appl. Numero Special, pp. 99–120.Google Scholar
Browand, F. K. & Weidman P. D. 1976 Large scales in the developing mixing layer. J. Fluid Mech. 76, 127–144.Google Scholar
Brown, G. L. & Roshko A. 1974 On density effects and large structure in turbulent mixing layers. J. Fluid Mech. 64, 775–816.Google Scholar
Cimballa J. M. 1984 Large structure in the far wakes of two-dimensional bluff bodies. Ph.D. thesis, California Institute of Technology.
Cohen, J. & Wygnanski I. 1987 The evolution of instabilities in the axisymmetric jet. Part 2. Flow resulting from the interaction of two waves. J. Fluid Mech. 176, 221–235.Google Scholar
Crow, S. C. & Champagne F. H. 1971 Orderly structure in jet turbulence. J. Fluid Mech. 48, 547–591.Google Scholar
Gaster M., Kit, E. & Wygnanski I. 1985 Large-scale structures in a forced turbulent mixing layer. J. Fluid Mech. 150, 23–39.Google Scholar
Hama F. R. 1962 Streaklines in a perturbed shear flow. Phys. Fluids 5, 644–650.Google Scholar
Hernan, M. A. & Jimenez J. 1982 Computer analysis of a high-speed film of the plane turbulent mixing layer. J. Fluid Mech. 119, 323–345.Google Scholar
Ho, C. M. & Huang L. S. 1982 Subharmonics and vortex merging in mixing layers. J. Fluid Mech. 119, 443–473.Google Scholar
Ho, C. M. & Huerre P. 1984 Perturbed free shear layers. Ann. Rev. Fluid Mech. 16, 365–424.Google Scholar
Kelly R. E. 1967 On the stability of an inviscid shear layer which is periodic in space and time. J. Fluid Mech. 27, 657–689.Google Scholar
Michalke A. 1964 On the inviscid instability of the hyperbolic tangent velocity profile. J. Fluid Mech. 19, 543–556.Google Scholar
Oster, D. & Wygnanski I. 1982 The forced mixing layer between parallel streams. J. Fluid Mech. 123, 91–130.Google Scholar
Roberts F. A. 1985 Effects of periodic disturbance on the structure and mixing in turbulent shear layers and wakes. Ph.D. thesis, California Institute of Technology.
Weisbrot, I. & Wygnanski I. 1988 On coherent structures in a highly excited turbulent mixing layer. J. Fluid Mech. 195, 137–159.Google Scholar
Winant, C. D. & Browand F. K. 1974 Vortex pairing, the mechanism of turbulent mixing-layer growth at moderate Reynolds numbers. J. Fluid Mech. 63, 237–255.Google Scholar
Wygnanski, I. & Petersen R. A. 1985 Coherent motion in excited free shear flow. AIAA Paper 85–0539.Google Scholar