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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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