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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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.
|Item Type:||Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)|
|Uncontrolled Keywords:||non-Boussinesq convection; spatio-temporal instability; Ginzburg-Landau equation|
|Subjects:||240000 Physical Sciences > 240500 Classical Physics > 240502 Fluid Physics
230000 Mathematical Sciences > 239900 Other Mathematical Sciences > 239999 Mathematical Sciences not elsewhere classified
|Depositing User:||Dr Sergey Suslov|
|Date Deposited:||11 Oct 2007 00:52|
|Last Modified:||02 Jul 2013 22:40|
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