Instability of a free-shear layer in the vicinity of a viscosity-stratified layer

Sahu, K C and Govindarajan, R (2014) Instability of a free-shear layer in the vicinity of a viscosity-stratified layer. Journal of Fluid Mechanics, 752. pp. 626-648. ISSN 0022-1120

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Abstract

The stability of a mixing layer made up of two miscible fluids, with a viscosity-stratified layer between them, is studied. The two fluids are of the same density. It is shown that unlike other viscosity-stratified shear flows, where species diffusivity is a dominant factor determining stability, species diffusivity variations over orders of magnitude do not change the answer to any noticeable degree in this case. Viscosity stratification, however, does matter, and can stabilize or destabilize the flow, depending on whether the layer of varying velocity is located within the less or more viscous fluid. By making an inviscid model flow with a slope change across the 'viscosity' interface, we show that viscous and inviscid results are in qualitative agreement. The absolute instability of the flow can also be significantly altered by viscosity stratification.

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IITH Creators:
IITH CreatorsORCiD
Item Type: Article
Uncontrolled Keywords: convective/absolute instability; multiphase flows; shear layers
Subjects: Chemical Engineering > Biochemical Engineering
Divisions: Department of Chemical Engineering
Depositing User: Team Library
Date Deposited: 23 Dec 2014 06:10
Last Modified: 05 Mar 2015 09:42
URI: http://raiithold.iith.ac.in/id/eprint/1230
Publisher URL: http://dx.doi.org/10.1017/jfm.2014.361
OA policy: http://www.sherpa.ac.uk/romeo/issn/0022-1120/
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