Slip flow in microchannels

Abstract

The assumption that a liquid adheres to a solid boundary ("no-slip" boundary condition) is one of the central tenets of the Navier-Stokes theory. However, there are situations wherein this assumption does not hold.One-dimensional single phase models for microchannel flow with slip flow boundary conditions have been presented here. The geometry of the problem and meshing of it have been made in GAMBIT. The simulation of steady incompressible fluid flow and heat transfer is done using ANSYS 13 FLUENT Software. Usually, the slip is assumed to depend on the shear stress at the wall.In the present work, the slip flow of liquid through a microchannel has been modeled using a slip length assumption instead of using conventional Maxwell’s slip flow model, which essentially utilizes the molecular mean free path concept. The hydrodynamics and thermal behaviour of a rectangular microchannel are studied here. The variation wall temperature, pressure drop in the channel and the friction factors calculated using ANSYS Fluent can well predict the experimental data. The effect of Re on the behaviour the channel are also studied. The models developed, following this approach, lend an insight into the physics of liquid flow through microchannels. Initially, in order to study the physics of flow inside the microchannel a simple analysis was done in a circular pipe.