NATURAL-CONVECTION IN RECTANGULAR ENCLOSURES WITH ADIABATIC FINS ATTACHED ON THE HEATED WALL

The heat transfer by natural convection in vertical and inclined rectangular enclosures with fins attached to the heated wall is numerically studied using the energy and Navier-Stokes equations with the Boussinesq approximation. The range of study covers 10(4) less-than-or-equal-to Ra less-than-or-equal-to 2 x 10(5), A = H'/L' = 2.5 to infinity, B = l'/L' = 0 to 1, C = h'/L' = 0.25 to 2 and Pr = 0.72. The inclination angle from the vertical was from 0 to 60 degree. The variation of the local Nusselt number Nu(loc) along the enclosure height and the average Nusselt number Nu as a function of Ra are computed. Streamlines and isotherms in the enclosure are produced. The results show that B is an important parameter affecting the heat transfer through the cold wall of the enclosure. The heat transfer is reduced for decreasing C and it passes from a maximum for an inclination angle. The results show that the heat transfer can generally be reduced using appropriate geometrical parameters in comparison with a similar enclosure without fins.