Abstract
Mixed convection heat transfer for laminar air flow in an open cavity is studied numerically by finite element method using software package (FlexPDF) to solve the conservation of governing equations. Three basic heating modes are considered: case 1, the heated wall is the horizontal surface of the cavity (heating from below) at uniform temperature, case 2, all the walls of the cavity are isothermal, and case 3, all walls of the cavity and the bottom wall of the channel are kept at constant temperature, for each case the boundary condition of the other walls are adiabatic. The results in terms of streamlines, isotherms, average temperature of the fluid and average Nusselt number of the heated wall are presented for Ri = 0 to 5, Re=100 , Pr = 0.71, and cavity aspect ratio (L/D) is in the range from(1–2). The present results show that the aspect ratio and Ri are affect on streamline and isotherm patterns for different heating configurations. In addition, the thermal performance in terms of both the overall heat transfer coefficient and bulk mean temperature of fluid is affected by the two parameters.
The results of streamlines and isotherms are compared with available result of (Manca et al.,2003)[10] and a good agreement has been achieved.
