EXPERIMENTAL AND NUMERICAL INVESTIGATION FOR THE NATURAL CONVECTION HEAT TRANSFER IN AN ENCLOSURE HAVING BAFFLES

In this paper, the natural convection heat transfer in a cubic enclosure provided with inclined baffles attached to the two adiabatic sides, heated from the bottom is studied experimentally and numerically to assess the effect of the baffles on the heat transfer process inside the enclosure. Two different configurations have been considered. The first configuration corresponds to the heated from the bottom with uniform heat flux using two baffles attached to the left and right walls, while the second configuration corresponding that the enclosure's floor has parallel bands that are heated to a constant, high temperature and the bands are separated by gaps that are kept at a lower temperature that is also constant and single baffle attached to the left wall. In both cases, the top wall is kept at a lower temperature than the bottom wall and the inclined baffles are well covered with an insulating material. The inclination angles of the baffles range as (0o ≤ and ≥ 150o ). The governing parameter, Rayleigh number, is fixed within 2.6x1011. In numerical solution, a commercial software package has been used for a 2-D computation, and the effect of turbulence is modelled by using (k-ε) model. Depending on its orientation, the partial baffle has been found to change significantly the flow field which in turn causes a reduction to the heat exchange inside the enclosure due to the damping caused to the flow field. For all cases, the insulated baffle with any inclination angle caused a reduction to the heat exchange inside the enclosure due to the damping caused to the flow field. Also, a good agreement has been obtained between experimental measurements and numerical results.