International Journal of Heat and Mass Transfer, Vol.40, No.4, 893-903, 1997
A Numerical Study of Unsteady Free-Convection from a Sphere in a Porous-Medium
In this paper a transient free convection flow from a sphere which is embedded in a porous medium has been considered. The temperature or heat flux of the sphere is suddenly raised and subsequently maintained at constant values over the surface. The coupled governing equations of the Darcy flow and energy are solved numerically for both small and large values of the Rayleigh number using a classical finite-difference method. Transient and steady-state flow and temperature patterns around this sphere are discussed in detail and a comparison of the overall Nusselt number with some earlier results shows very good agreement.
Keywords:NATURAL-CONVECTION