Lattice Boltzmann modelling Knudsen layer effect in non-equilibrium flows

Due to its intrinsically kinetic nature, lattice Boltzmann (LB) approach to simulating non-equilibrium gas flows has recently attracted significant research interest. Compared with other kinetic methods, it can offer a significantly smaller computational cost. To capture the nonlinear high-order rarefaction phenomena in gas flows, a geometry-dependent gas local mean free path has been proposed to be implemented in our "high-order" LB model. A series of tests on rarefaction effects and the Knudsen layer interference have been carried out and the simulation results demonstrate our LB model's capability for highly non-equilibrium flows.