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The density of organized vortices in a turbulent mixing layer

Published online by Cambridge University Press:  29 March 2006

D. W. Moore
Affiliation:
Department of Mathematics, Imperial College, London
P. G. Saffman
Affiliation:
Applied Mathematics, California Institute of Technology, Pasadena

Abstract

It is argued on the basis of exact solutions for uniform vortices in straining fields that vortices of finite cross-section in a row will disintegrate if the spacing is too small. The results are applied to the organized vortex structures observed in turbulent mixing layers. An explanation is provided for the disappearance of these structures as they move downstream and it is deduced that the ratio of average spacing to width should be about 3·5, the width being defined by the maximum slope of the mean velocity. It is shown in an appendix that walls have negligible effect.

Type
Research Article
Copyright
© 1975 Cambridge University Press

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