Thermal Viscous Dissipative Couette Flow in a Porous Medium Filled Microchannel

Abstract

The increasing demand for high-performance electronic devices and surge in power density accentuates the need for heat transfer enhancement. In this study, a thermal viscous dissipative Coeutte flow in a micochannel filled with fluid saturated porous medium is looked into. The study explores the fluid flow and heat transfer phenomenon for a Coeutte flow in a microchannel as well as to establish the relationship between the heat convection coefficient and viscous dissipation. The moving boundary in this problem is subjected to uniform heat flux while the fixed plate is assumed adiabatic. In order to simplify the problem, we consider a fully developed flow and assume local thermal equilibrium in the analysis. An analytical Nusselt number expression is developed in terms of Brinkman number as a result of this study, thus providing essential information to predict accurately the thermal performance of a microchannel. The results obtained without viscous dissipation are in close agreement with published results whereas viscous dissipation has a more significant effect on Nusselt number for a porous medium with higher porous medium shape factor. The Nusselt number versus Brinkman number plot shows an asymptotic Brinkman number, indicating a change in sign of the temperature difference between the bulk mean temperature and the wall temperature. The effects of Reynolds number on the two dimensional temperature profile for a Couette flow in a microchannel are investigated. The temperature distribution of a microscale duct particularly along the axial direction is a strong function of viscous dissipation. The significance of viscous dissipation to a microscale duct as compared to a conventional scale duct is also discussed and compared in this study.