Effect of baffle number on mixed convection within a ventilated cavity

Abstract

Transverse mixed convection is studied numerically in a ventilated cavity with uniform heat flux on the bottom wall and the remaining walls are adiabatic. Our purpose was to see the influence of the baffle number on the variation of average Nusselt number. An air flow inlet in to the cavity through an opening in the lower part of the left vertical wall and another opening in the opposite wall (i.e., the bottom part BB configuration; the top part BT configuration). The number of baffles ranged between 1 and 4. The two-dimensional mathematical model includes a system of four equations with partial derivatives of continuity, momentum, and energy, solved by the finite volume method. Flow fields are studied by numerical simulations to the air with a Richardson number in the range1≤ Ri ≤10, for the Grashof number is fixed atGr =104, aspect ratio of the cavity A = 2, the height openings w = 0.1 and Prandtl number Pr = 0.71. The results show that the variation of the average Nusselt number and the average temperature depend on the type of configuration (BB or BT), and of the baffle number. The basic nature of the resulting interaction between the forced external air stream and the buoyancy-driven flow by the heat source is explained by the Nusselt number and the patterns of the streamlines and isotherms.