Experiments on Forced Convection From a Horizontal Heated Plate in a Packed Bed of Glass Spheres

This paper presents an experimental investigation of boundary-layer forced convective heat transfer from a flat isothermal plate in a packed bed of spheres. Extensive experimental results are reported for the thermal boundary-layer thickness, the temperature field, and the local wall heat flux (represented by the local Nusselt number). Theoretical findings of previous investigations using the Darcy flow model as well as a general model for the momentum equation accounting for flow inertia and macroscopic shear with and without variable porosity are used to evaluate the theoretical models. Several trends are revealed regarding the conditions of validity of these flow models. Overall, the general flow model including variable porosity appears to perform better, even though the need for serious improvements in modeling becomes apparent.