Numerical Study of Natural Convective Heat Transfer in an Air Filled Square Cavity Heated from Below and Symmetrically Cooled from the Sides with a Partition in the Hot Wall

A two-dimensional numerical study of laminar natural convection in a square enclosure filled with air with a wall partially heated on the bottom is presented. The heat source is located on the lower wall with different heated widths varied from 20 to 80% (epsilon = 0.2-0.8) of the total width of the lower wall and different heights h = H/4 and H/2 of the partition. The effect of the partition height on the main system dynamics is investigated through solution of the two-dimensional Navier-Stokes equations and the energy equation by means of a finite volume method based on the SIMPLE algorithm. The influence of the Rayleigh number (Ra = 103 to 106) and the hot wall length is also examined. It is shown that the average Nusselt number grows when epsilon increases and when h decreases. For a given value of epsilon and h, the average Nusselt number increases as Ra increases. It is concluded that the partition height causes a decrease in the average Nusselt number.