Lattice Boltzmann BGK model for gas flow in a microchannel

摘要

As microdevices have to be operated in a fluid medium, the understanding of flow at a microlevel is fundamental for the development of microelectromechanical systems. In the present work, the velocity distribution in a rectangular cross-section and the pressure drop along the length of the microchannel are studied using different expressions for the complete momentum accommodation coefficient and relaxation time in the lattice Boltzmann method, BGK model (LBGK), with the transition region 0.1 < Kn < 0.5 and low Reynolds number Re < 1. By taking into account the correction for the Knudsen number, complete accommodation coefficient and relaxation time, the number of iterations will reduce considerably in simulation. Also, results obtained in the two-dimensional microchannel with an aspect ratio of 50 are in good agreement with the analytical and numerical predictions. [PUBLICATION ABSTRACT]