Instabilities induced by variation of Brunt-Vaisala frequency in compressible stratified shear flows

Narayanan, A Satya and Sachdev, PL (1982) Instabilities induced by variation of Brunt-Vaisala frequency in compressible stratified shear flows. In: Physics of Fluids, 25 (8). 1317 -1321.

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Abstract

The stability characteristics of a Helmholtz velocity profile in a stably stratified, compressible fluid in the presence of a lower rigid boundary are studied. A jump in the Brunt-Vaisala frequency at a level different from the shear zone is introduced and the variation of the Brunt-Vaisala frequency with respect to the vertical coordinate in the middle layer of the three-layered model is considered. An analytic solution in each of the layers is obtained, and the dispersion relation is solved numerically for parameters relevant to the model. The effect of shear in the lowermost layer of the three-layered model for a Boussinesq fluid is discussed. The results are compared with the earlier studies of Lindzen and Rosenthal, and Sachdev and Satya Narayanan. In the present model, new unstable modes with larger growth rates are obtained and the most unstable gravity wave modes are found to agree closely with the observed ones at various heights. Physics of Fluids is copyrighted by The American Institute of Physics.

Item Type:	Journal Article
Publication:	Physics of Fluids
Publisher:	American Institute of Physics
Additional Information:	Copyright of this article belongs to American Institute of Physics.
Department/Centre:	Division of Physical & Mathematical Sciences > Mathematics
Date Deposited:	25 Aug 2009 11:02
Last Modified:	19 Sep 2010 05:36
URI:	http://eprints.iisc.ac.in/id/eprint/21306

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