Convective heat transfer from a heated vertical plate surrounded by a saturated porous medium

The results of an experimental examination of the heat transfer characteristics of a vertical plate embedded in a water-satured porous medium (beads and gravel) are described. Results are presented for the variation of local Nusselt number for different heat fluxes in free convection in water-saturated spherical glass beads and irregular shaped gravel. Qualitative results from the flow visualization experiments for the bead medium boundary layer flow are also included. The flow was made visible by the use of the electrochemical formation of dye technique. It is shown that the power law used to describe the variation of the Nusselt number with Rayleigh number for free convection, Nu = A Raⁿ, is not effective as it is for heat transfer in water. The values of A and n vary within each run and from one heat flux to another. Values of A and n are tabulated for different heat fluxes.