Simulation of Rarefied Gas Flow in Slip and Transitional Regimes by the Lattice Boltzmann Method
Keywords:distribution function, Boltzmann equation, BGK collision model, microscale flow, microchannel
In this paper, a lattice Boltzmann method (LBM) based simulation of microscale flow has been carried out, for various values of Knudsen number. The details in determining the parameters critical for LBM applications in microscale flow are provided. Pressure distributions in the slip flow regime are compared to the analytical solution based on the Navier-Stokes equation with slip-velocity boundary condition. Satisfactory agreements have been achieved. Simulations are then extended to transition regime (Kn = 0.15) and compared with the same analytical solution. The results show some deviation from the analytical solution due to the breakdown of continuum assumption. From this study, it can be concluded that the lattice Boltzmann method is an efficient approach for simulation of microscale flow.