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

The problem of mixed convection heat transfer in a square cavity with a centered heat conductinghorizontal square solid cylinder is analyzed in this paper. As boundary conditions of the cavity, theright vertical wall is kept at constant temperature and the remaining three walls are kept thermallyinsulated. An external flow enters the cavity through an opening in the left vertical wall and exitsfrom another opening in the right vertical wall. This configuration leads to a conjugate heat transferproblem and simulates the cooling of electronic equipments. Emphasis is placed on the influences ofthe governing parameters, such as Reynolds number, Richardson number, Prandtl number and theinlet and exit port locations of the cavity. The coupled equations of the simulated model are solvednumerically using finite element method. Finally, parametric results are presented in terms ofstreamlines, isotherms, average Nusselt number at the heated wall, average temperature of the fluidand the temperature at the cylinder center in the cavity. The computational results indicate thatReynolds number has significant effect on the flow field in the pure forced convection and in thepure mixed convection region, but Prandtl number has significant effect on the flow field in the puremixed convection and in the free convection dominated region. On the other hand, the mentionedparameters 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 thermalfields in the three convective regimes.

Keywords:

Heat transfer , finite element method , mixed convection , square cylinder , square cavity