MIXED CONVECTION IN A SQUARE CAVITY WITH A HEAT-CONDUCTING HORIZONTAL SQUARE CYLINDER

The problem of mixed convection heat transfer in a square cavity with a centered heat conducting horizontal square solid cylinder is analyzed in this paper. As boundary conditions of the cavity, the right vertical wall is kept at constant temperature and the remaining three walls are kept thermally insulated. An external flow enters the cavity through an opening in the left vertical wall and exits from another opening in the right vertical wall. This configuration leads to a conjugate heat transfer problem and simulates the cooling of electronic equipments. Emphasis is placed on the influences of the governing parameters, such as Reynolds number, Richardson number, Prandtl number and the inlet and exit port locations of the cavity. The coupled equations of the simulated model are solved numerically using finite element method. Finally, parametric results are presented in terms of streamlines, isotherms, average Nusselt number at the heated wall, average temperature of the fluid and the temperature at the cylinder center in the cavity. The computational results indicate that Reynolds number has significant effect on the flow field in the pure forced convection and in the pure mixed convection region, but Prandtl number has significant effect on the flow field in the pure mixed convection and in the free convection dominated region. On the other hand, the mentioned parameters have significant effect on the thermal field in the three convective regimes considered. Lastly, the locations of the inlet and outlet port have significant effect on both the flow and thermal fields in the three convective regimes.