Mixed convection in a generation of periodic and unsteady13; convection.13;

Deshpande, MD and Srinidhi, BG (2005) Mixed convection in a generation of periodic and unsteady13; convection.13;. Technical Report. National Aerospace Laboratories, Bangalore, India.

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Abstract

Mixed convection in a cavity formea by a rectangular parallelepiped of spanwise aspecl ratio three has been studied by solving the Navier-Stokes and the energy equations unda the Boussinesq approximation. Buoyancy forces are due to the heating of the bottom wall and forcing due to the motion of the top lid. Attention is specially paid to the appearance of the periodic motion which was observed in a narrow band of Rayleigh number Ra for a given value of Reynolds number Re. When Ra is increased the flow passes through a steady, periodic, quasiperiodic, unsteady and turbulent flow regimes not13; necessarily in that order. Surprisingly there has been a case when a steady flow became quasiperiodic and then periodic when Ra was increased. Dependence of these flow13; regimes (represented by Ra) on Re is non-monotonic indicating the complex nature of the interaction of the two forces. Periodic motions may be associated with symmetry in the spanwise direction or not. When such a symmetry is there it disappears when the periodicity is lost. On the other hand the unsymmetrical solution in the spanwise direction when periodicity is present indicates that another set of solutions with a mirror reflection in this direction is possible.The classical features of a dynamical system like bifurcation and period dubling usually observed in the phase space are also seen in the physical space of the cavity.

Item Type: Monograph (Technical Report)
Uncontrolled Keywords: Navier-stokes equations;Yenodic solutions;Bifurcation;Period doubling;Flow symmetry;Nusselt number
Subjects: AERONAUTICS > Aeronautics (General)
Depositing User: Users 10 not found.
Date Deposited: 03 Feb 2009
Last Modified: 24 May 2010 04:09
URI: http://nal-ir.nal.res.in/id/eprint/838

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