Effect of spatial porosity of metal foams on heat transfer filled in a vertical channel

Abstract This paper presents the numerical examination of the effect of spatial porosity variation of aluminum metal foams filled in a vertical channel. The physical domain comprises of a vertical channel in which aluminum plate cum heater assembly is placed at the center of the channel. The heat transfer from the aluminum plate is enhanced by using aluminum metal foams of different pore densities of 10, 20, 30, and 45 with varied porosities are considered in the present examination. A conjugate heat transfer analysis is carried out with the help of ANSYS FLUENT for a fluid inlet velocity of 0.1 – 1.5 m/s. The flow-through metal foam porous medium is predicted with the help of Darcy Extended Forchheimer model while heat transfer is predicted using the local thermal non-equilibrium model. The numerical methodology adopted in the current work is validated by comparing the present results with the literature. The hydrodynamic characteristics such as pressure drop and friction factor and thermal characteristics represented by Nusselt number, Colburn j factor, and overall performance factor are discussed in the present numerical investigation. The results of spatially varied porosity of metal foams are compared with uniform porosity metal foam. It is observed from the results that the spatial variation in porosity for the considered metal foam and the considered thickness of the channel does not significantly improve heat transfer but a slight decrease in pressure drop is observed compared to uniform porosity metal foam.