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Nonlinear roll-up of externally excited free shear layers

Published online by Cambridge University Press:  21 April 2006

M. E. Goldstein
Affiliation:
National Aeronautics and Space Administration, Lewis Research Center, Cleveland, OH 44135, USA
S. J. Leib
Affiliation:
Case Western Reserve University, Cleveland, OH 44106, USA and NASA Resident Research Associate

Abstract

We consider the effects of strong critical-layer nonlinearity on the spatially growing instabilities of a shear layer between two parallel streams. A composite expansion technique is used to obtain a single formula that accounts for both shear-layer spreading and nonlinear critical-layer effects. Nonlinearity causes the instability to saturate well upstream of the linear neutral stability point. It also produces vorticity roll-up that cannot be predicted by linear theory.

Type
Research Article
Copyright
© 1988 Cambridge University Press

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