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ISSN Online: 2377-424X

ISBN Print: 1-56032-797-9

International Heat Transfer Conference 11
August, 23-28, 1998, Kyongju, Korea

ANALYTICAL AND NUMERICAL SIMULATION OF DOUBLE-DIFFUSIVE CONVECTION IN A TILTED CAVITY FILLED WITH POROUS MEDIUM

Get access (open in a dialog) DOI: 10.1615/IHTC11.4100
pages 453-458

Resumo

We study the onset of double-diffusive convective regimes in a tilted rectangular cavity filled with a porous medium saturated by a binary fluid. Two walls are maintained at different but uniform temperatures and concentrations while the two other walls are impermeable and adiabatic. The ratio, N, of the solutal buoyancy contribution to the thermal buoyancy contribution is fixed to (-1). Then, the non-dimensionalized problem depends on five parameters which are: the thermal Rayleigh number, RaT, the Lewis number, Le, the normalized porosity, ε, the aspect ratio, A and the angle of tilt of the cell φ. We present the results of an analytical and numerical study of bifurcations from the purely diffusive state to steady or time-dependent convective regimes. Due to the symmetry properties, primary bifurcations are either transcritical or pitchfork depending on the aspect ratio and the tilt of the box. Our numerical simulations indicate that at primary pitchfork bifurcations, branches of linearly unstable steady solutions are created. In addition, we show that, for Le>l and εLe2 < 1, the first primary bifurcation is a Hopf bifurcation. This result is validated for several values of the aspect ratio and angle of tilt. For Le<l and for several angles of tilt, we have determined the range of (ε, Le) in which the first primary bifurcation is a Hopf bifurcation. The results we obtained from the linear stability analysis are in a good agreement with our numerical simulation of the flow.