Numerical Simulation of Gaseous Microflows by Lattice Boltzmann Method

This work is concerned with application of the Lattice Boltzmznn Method (LBM) to compute flows in micro-geometries. The choice of using LBM for microflow simulation is a good one owing to the fact that it is based on the Boltzmann equation which is valid for the whole range of the Knudsen number. In this work LBM is applied to simulate the pressure driven microchannel flows and micro lid-driven cavity flows. First, the microchannel flow is studied in some details with the effects of varying the Knudsen number, pressure ratio and Tangential Momemtum Accomodation Coefficient (TMAC). The pressure distribution and other parameters are compared with available experimental and analytical data with good agreement. After having thus established the credibility of the code and the method including boundary conditions, LBM is then used to investigate the micro lid-driven cavity flow. The computations are carried out mainly for the slip regime and the threshold of the transition regime.