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The interaction between the mean flow and coherent structures in turbulent mixing layers

Published online by Cambridge University Press:  26 April 2006

J. Cohen
Affiliation:
Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
B. Marasli
Affiliation:
Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
V. Levinski
Affiliation:
Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel

Abstract

The nonlinear interaction between the mean flow and a coherent disturbance in a two-dimensional turbulent mixing layer is addressed. Based on considerations from stability theory, previous experimental results, in particular the modification of the mean velocity profile, the peculiar growth of the forced shear-layer thickness and the spatial growth of the disturbance amplitude, are explained. A model that assumes a quasi-parallel mean flow having a self-similar mean velocity profile is developed. The model is capable of predicting the downstream evolution of turbulent mixing layers subjected to external excitations.

Type
Research Article
Copyright
© 1994 Cambridge University Press

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