Fluid Flow and Heat Transfer Simulation in a Constricted Microchannel: Effects of Rarefaction, Geometry, and Viscous Dissipation

Abstract

The present work concerns the developing fluid flow and heat transfer through a constricted microchannel in slip flow regime with constant wall temperature. The effects of rarefaction and geometry are investigated on the thermally/hydrodynamically developing fluid flow, while the effect of viscous dissipation is involved. Also the effects of creeping flow, first-order slip boundary conditions are included. The main purpose of this work is to investigate the combined effects of rarefaction, creeping flow, and viscous dissipation on hydrodynamically and thermally flow characteristics, especially C _f  · Re and Nusselt number. Here, governing equation includes continuity, momentum, and energy in the presence of slip velocity and temperature jump at the solid walls. These equations are discretized by a finite volume scheme and solved using the SIMPLE algorithm in curvilinear coordinate. Simulation was carried out for a range of Knudsen number Kn = 0.01–0.1 and amplitude of wave a = 0.1–0.2. It is found that involving the effect of viscous dissipation considerably affects the thermal fluid pattern and also increases the Nusselt number. It is also found that the Knudsen number has a declining effect on both the C _f  · Re and Nusselt number. The obtained results are in good agreement with available numerical data.