Effect of fluid properties variations on spatio-temporal instability of convection

Suslov, Sergey A. (2002) Effect of fluid properties variations on spatio-temporal instability of convection. In: APM 2001: 29th Summer School on 'Advanced Problems in Mechanics, 21-30 Jun 2001, St Petersburg (Repino), Russia.

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Abstract

The classical problem of stability of convection flow in a tall vertical differentially heated rectangular cavity is considered. It is shown that realistic nonlinear fluid properties variations associated with a large cross-cavity temperature gradient lead to significant deviations from the flow scenarios predicted using conventional Boussinesq approximation. It is well known that in the Boussinesq limit of a small temperature gradient the conduction state bifurcates supercritically to a stationary transverse roll pattern associated with the shear of the primary flow, and this instability is of absolute character. Here we show that when the fluid properties vary, a new buoyancy driven oscillatory instability arises, the transition to shear driven instability becomes subcritical, and a range of parameters appears for which the character of instability is convective. Analytical results are obtained by deriving and solving the Ginzburg-Landau-type disturbance amplitude equation and are checked against the results of direct numerical simulation.


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: Yes
Item Status: Live Archive
Depositing User: Dr Sergey Suslov
Faculty / Department / School: Historic - Faculty of Sciences - Department of Maths and Computing
Date Deposited: 11 Oct 2007 00:52
Last Modified: 02 Jul 2013 22:40
Uncontrolled Keywords: non-Boussinesq convection; spatio-temporal instability; Ginzburg-Landau equation
Fields of Research (FOR2008): 02 Physical Sciences > 0203 Classical Physics > 020303 Fluid Physics
01 Mathematical Sciences > 0105 Mathematical Physics > 010599 Mathematical Physics not elsewhere classified
Socio-Economic Objective (SEO2008): E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
URI: http://eprints.usq.edu.au/id/eprint/1806

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