In this article, we investigate the effects of the Darcy and Prandtl numbers on steady-state natural convection in an isoceles porous triangular cavity whose horizontal base is partially heated and whose upper walls are cooled. The uniform heat source is located centrally at the base wall. The isosceles triangular geometry directly simulates the attics of buildings. This model is widely used to optimise thermal insulation in the building sector. Darcy-Brinkman model is used. It is also assumed the fluid used is incompressible and obeys the Boussinesq approximation. The non-dimensionless governing equations, stream function-vorticity, momentum and energy are discretized by finite difference method and solved using the successive over-relaxation (SOR) method. Streamline and isotherm patterns were presented at different, length of heater
, Darcy number (
), Prandtl number (
) and for different Rayleigh number (
). On the basis of the results, it is observed that the Darcy number has an effect on both the initiation of convection and the average Nusselt number. The critical Rayleigh number where convection becomes the dominant heat transfer mode decreases significantly with increasing Darcy number. The mean Nusselt number increases with increasing Darcy number. The Prandtl number has a limited effect on overall heat transfer in the present system, for the range of values used.
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