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An experimental and theoretical study of internal waves generated by the collapse of a two-dimensional mixed region in a density gradient

Published online by Cambridge University Press:  29 March 2006

A. H. Schooley  and
B. A. Hughes
A. H. Schooley
Affiliation:
Naval Research Laboratory, Washington, D.C.
B. A. Hughes
Affiliation:
Defence Research Establishment Pacific, Forces Mail Office, Victoria, B.C., Canada
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Abstract

Previously reported experiments with a self-propelled body submerged in a fluid with a stable vertical density gradient have demonstrated that the turbulently mixed wake first expands more or less uniformly and then collapses vertically while continuing to expand horizontally (Schooley & Stewart 1963). It was also shown that the vertical collapse of the wake generates internal waves. Essentially two-dimensional experiments have also been used to explore some of the build-up and decay characteristics of vertical wake collapse induced by a sub-merged burst of turbulent mixing (Wu 1969; Schooley 1968). The present paper reports new experimental measurements and a linear theoretical analysis of the internal wave field created in stratified water by a burst of submerged turbulent mixing. The forcing function has been obtained in integral form for an initial-value model of wake collapse in terms of a general Brunt-Väisälä frequency profile, using normal mode theory. Numerical results have been determined for the specialized case of a completely mixed circular wake in a constant Brunt-Väisälä profile. These results are compared to the experimental measurements.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 51 , Issue 1 , 11 January 1972 , pp. 159 - 175
Copyright
© 1972 Cambridge University Press

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