LAMINAR FREE CONVECTION BETWEEN TWO VERTICAL PARALLEL PLATES WITH DIFFERENT RIB HEIGHTS AND POSITIONS
In this paper, it is presented the results of a numerical study of laminar free convection between two vertical parallel plates heated isothermally and symmetrically with height L and the distance w between them; where the geometric parameter was unchanged AR = L / w = 10. The temperature of the medium under the plates and above them was the same and different from the temperature of the plates TH > T0. The first case is at the half height of the channel (y / w = 5), on one of its walls, a thin adiabatic rib was normally placed on the surface. Its height in the calculations varied over a wide range l / w = 0 ÷ 0.8. The second case at the same height is fixed an opposite adiabatic ribs on the two sides of the channel, with heights ranges, l / w = 0 ÷ 0.4. The third case is as in the second one where, l / w = 0.4, but the ribs position is changing along the height of the channel at; the inlet, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, the exit. The numerical solution of the problem was carried out for air, where Pr = 0.71 for different values of the Rayleigh number, Ra = 102 ÷ 105, by solving the Navier-Stokes and energy equations using the finite volume method, in non-dimensional form, taking into account the thermo-gravitational forces.