Heat Transfer in a Lid-Driven Enclosure Filled with Water-Saturated Aluminum Foams

Abstract

Mixed convection in a lid-driven square enclosure filled with water-saturated aluminum foams is investigated numerically. The driving forces of fluid flow in such a system include the buoyancy force due to temperature gradient and the shear force due to lid movement, while the interaction of these forces results in various heat transfer modes. This work uses the Brinkman-Forchheimer model for fluid flow and the two-equation model for heat transfer. The top moving wall and the bottom heated wall are maintained at different constant temperatures, while the other walls are thermally insulated. The relevant parameters are the porosity of aluminum foams (ε = 0.91, 0.97), the Grashof number (Gr = 10⁴–3 × 10⁶) and the Reynolds number (Re = 10⁻²–10⁴). The fluid flow and heat transfer characteristics of the present porous system are identified. Parametric study indicates that the average Nusselt number (Nu) generally increases with Gr and Re. The higher porosity promotes much more enhancement of convective heat transfer, but the lower porosity is desired for higher total heat transfer due to the higher value of effective thermal conductivity. Finally, the Nu correlation is established based on the numerical results.

The authors would like to thank the National Science Council of the Republic of China, Taiwan, for financially supporting this research under Contract NSC-96-2628-E-150-007.