Slip flow in porous micro-tubes under local thermal non-equilibrium conditions

In the present work, forced convection heat transfer of slip flow in porous micro-tubes with local thermal non-equilibrium between the gas and the solid matrix is investigated numerically. For this purpose, the flow is considered hydrodynamically developed but thermally developing. The Darcy-Brinkman-Forchheimer model in conjunction with separate energy equations for the gas and the solid matrix is used to describe the flow and heat transfer in the porous media. Moreover, both velocity slip and temperature jump are applied to the fluid at the wall. Simulation results are presented in terms of velocity field, distributions of the fluid and solid temperatures, the local Nusselt number, and the thermal entry length. The results indicate heat transfer improvement as a result of increase in the Peclet/Biot number. Increase in the Knudsen number or the modified conductivity ratio, however, diminishes the heat transfer rate. Although the choice of the Darcy/Forchheimer number may change the computational results, trends are not similar in the developing and the developed regions of the flow.