Developing Free-Convection Gas Flow in a Vertical Open-Ended Microchannel Filled with Porous Media

Abstract

Abstract The developing hydrodynamic and thermal behaviors of free convection gas flow in a vertical open-ended parallel-plate microchannel filled with porous media are investigated numerically. The extended Darcy-Brinkman-Forchheimer model is used to model the flow in porous medium and the solid and fluid media are not assumed in local thermal equilibrium. The microflow regime considered is the slip flow regime. The slip in velocity and jump in temperature are found to decrease in the axial direction of the flow. The friction factor is found to decrease as Knudsen number, Forchheimer number and Grashof number are increased. However, the friction factor is found to increase as Darcy number increased. On the other hand, Nusselt number is found to decrease as Knudsen number, Darcy number and thermal conductivity ratio are increased, whereas it increased as Forchheimer number, Grashof number and Biot number are increased.