An investigation of natural convective flow and heat transfer inside a three
dimensional rectangular cavity containing an array of discrete heat sources is carried
out. The array consists of a row and columnwise regular arrangement of identical
square shaped isoflux discrete heaters and is flush mounted on a vertical wall of the
cavity. A symmetrical isothermal sink condition is maintained by cooling the cavity
uniformly from either the opposite wall or the side walls or the top and bottom walls.
The other walls of the cavity are maintained adiabatic. A finite volume method based
on the SIMPLE algorithm and the power law scheme is used to solve the conservation
equations. The parametric study covers the influence of pertinent parameters such as
the Rayleigh number, the Prandtl number, side aspect ratio of the cavity and cavity
heater ratio. A detailed fluid flow and heat transfer characteristics for the three cases
are reported in terms of isothermal and velocity vector plots and Nusselt numbers.
In general it is found that the overall heat transfer rate within the cavity for Ra =107
is maximum when the side aspect ratio of the cavity lies between 1.5 and 2. A more
complex and peculiar flow pattern is observed in the presence of top and bottom cold
walls which in turn introduces hot spots on the adiabatic walls. Their location and size
are highly sensitive to the side aspect ratio of the cavity and hence offers more effective
ways for passive heat removal.