Exergy Transfer and Irreversibility of Metal Foams Filled in a Vertical Channel

Abstract

The aim of this work is to unveil the exergy transfer and overall thermal performance of the metal foams partially filled in varying thicknesses in the vertical channel. The numerical examination performed in this study consists of a heater cum plate assembly which is placed at the core of the vertical channel and the heat transfer from the plates is augmented by placing high thermal conductivity metal foams on either side of the channel. The novelty of the present investigation is to find the optimum filling rate in various thicknesses of the channel with respect to overall thermal performance along with exergy transfer. Four different partial filling rates are considered in each thickness of the channel to find the optimum exergy transfer. The integrated Darcy Extended Forchheimer (DEF) and local thermal non-equilibrium (LTNE) models are used for forecasting the flow features and heat transfer through the metal foam porous medium. The numerical methodology implemented in this research is confirmed by comparing the results with the literature and found a fairly good agreement between them. The flow physiognomies in terms of pressure drop and friction factor, heat transfer performance in terms of Nusselt number and performance factor, exergy transfer in terms of mean exergy based Nusselt number are presented and discussed. Results showed that higher working limits permitted by exergy (WLPERe) is obtained for lesser metal foam filling rate as well as for higher metal foam thicknesses for all the cases examined in the study.