I. Sezai et Aa. Mohamad, Natural convection from a discrete heat source on the bottom of a horizontal enclosure, INT J HEAT, 43(13), 2000, pp. 2257-2266
Steady, natural convection from a discrete flush-mounted rectangular heat s
ource on the bottom of a horizontal enclosure is studied numerically. Three
-dimensional form of Navier-Stokes equations are solved by using multigrid
technique. Rayleigh number based on the enclosure height is varied from 10(
3) until unstable flow is predicted for a fixed Prandtl number of 0.71. Asp
ect ratio of the source is varied until it fully covered the entire width o
f the bottom plate. The enclosure is cooled from above and insulated from t
he bottom. Effect of vertical boundary conditions on the rate of heat trans
fer from the heat source is studied. It is found that the rate of heat tran
sfer is not so sensitive to the vertical wall boundary conditions. The limi
t of the maximum Rayleigh number to obtain a convergent solution decreases
as the aspect ratio of the sourer is increased. The variation of Nusselt nu
mber as a function of Rayleigh number and aspect ratio of the source is rep
orted. (C) 2000 Elsevier Science Ltd. All rights reserved.