Lattice Gas Automata of Fluid Dynamics for Unsteady Flow

Abst ract. We st udy lat tice gas automata. of fluid dynamics in the incompressible flow limit . It is shown t hat t he viscosity effect on the transition layer from the steady uniform velocity in one strea.m to the steady uniform velocity in another , adja cent strea m produces t he correct profile. We further study t he intr insic damping or smoothing action of viscous diffusion and show that the results agree wit h t hose obta ined from the Navier-Stc kes equation. In both cases, we obtain a. kinetic viscosity II '" 0.65, consistent with the prediction of Bolt zmann approximation.