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On the elimination of refractive-index variations in turbulent density-stratified liquid flows

Published online by Cambridge University Press:  19 April 2006

Trevor J. Mcdougall
Trevor J. Mcdougall
Affiliation:
Research School of Earth Sciences, Australian National University, P.O. Box 4, Canberra 2600
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Abstract

The variations in refractive index in stratified liquid flows have been a major impediment to the use of laser-Doppler anemometry in these situations. This paper describes a method whereby these refractive-index variations can be drastically reduced while retaining the dynamically important density differences. The method uses two solutes to produce the density differences and it is shown that double-diffusive convection (of the salt-finger type) can be avoided by using a suitable pair of solutes. A theoretical model of the lateral wander of a single laser beam propagating through a turbulent medium is developed and this explains the success of the method.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 93 , Issue 1 , 12 July 1979 , pp. 83 - 96
Copyright
© 1979 Cambridge University Press

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