A KNUDSEN LAYER THEORY FOR LATTICE GASES

A Knudsen layer theory is presented for lattice gases with arbitrary boundary conditions. Analytical results are obtained for two special orientations; these exhibit anisotropic Knudsen layers provided suitable conditions are satisfied. However, the standard boundary conditions used in previous simulations are shown to be isotropic, the bulk steady state extending everywhere in the gas. This theory allows a more accurate localization of the obstacle with respect to the lattice nodes. These results are in good agreement with the numerical simulations.