NATURAL CONVECTION HEAT TRANSFER IN A DIFFERENTIALLY HEATED ENCLOSURE WITH ADIABATIC PARTITIONS AND FILLED WITH A BINGHAM FLUID

The present numerical study deals with two-dimensional natural convection in a differentially heated square enclosure, with centrally located partitions and off set partitions. The cavity is considered to be completely filled with a yield fluid obeying the rheological model of Bingham. The governing equations were solved using a code based on the finite volume method. The code has been validated for both cases of a Newtonian and non-Newtonian fluid, aft er comparison between the present results and those given in the literature. In order to investigate the effect of a set of parameters, i.e., the partitions height and thickness, on heat and flow behaviors, the Prandtl number is taken equal to 20, the Rayleigh number is fixed at 106, and the Bingham number covers the range from 0 to 20. The results show, on the one hand, that the average Nusselt number is a decreasing function of the Bingham number and that all parameters related to geometrical dimensions of partitions exert a crucial effect on the flow field and heat transfer, on the other hand. Moreover, it has been pointed out that the position of such partitions has an important effect on both fluid flow and heat transfer and that the partitions thickness enhanced heat transfer.