Natural convection in an open square cavity with slots

In this paper, we investigate heat transfer by natural convection in an open cavity in which a uniform heat flux is applied to the inside active wall facing the opening with slots. Conservation equations are solved by finite difference-control volume numerical method. The relevant governing parameters are: the Rayleigh numbers from 10(3) to 10(6), the Prandtl number, Pr=0.7, constant for air, the cavity aspect ratio, A=L/H=1. Number of slots N is varied from 2 to 8 and the dimensionless opening ratio OR from 0.1 to 0.6. We found that the Nusselt number and the volume flow rate are both increasing functions of the Rayleigh number; they are a decreasing function of the number of slots and increasing function of the opening ratio. though there is an optimum opening ratio at high Rayleigh numbers. (C) 2008 Elsevier Ltd. All rights reserved.