Microchannel flow simulation in transition regime using lattice Boltzmann method

Abstract

In this article, lattice Boltzmann model (LBM) was used as a numerical method for microchannel flow simulation. Slip flow regime for which Knudsen number varies from 0.1 to 1.0 was investigated using an effective mean free path in relaxation-time-parameter of LBM. Computations were performed for pressure-driven and shear flow configurations of a microchannel. Nonlinear flow characteristics of Knudsen layer were captured in shear flow regime along with the phenomenon of slip length. The slip velocity was predicted in both flow configurations with good accuracy. For pressure-driven flow geometry, velocity distribution across the channel showed better correspondence with that of direct simulation Monte Carlo (DSMC) method for Knudsen numbers less than 0.5, as compared to those obtained from Navier–Stokes equations and conventional LBM simulation. While discrepancies were observed between present results and those of DSMC for Knudsen numbers greater than 0.5, present computations showed improved velocity profile as compared to Navier–Stokes and conventional LBM simulations.