SOME NEAR-EQUILIBRIUM PROPERTIES OF A NINE VELOCITIES LATTICE GAS AUTOMATON FOR TWO-DIMENSIONAL HYDRODYNAMICS

摘要

We discuss a 9-bit states cellular automaton model for two-dimensional hydrodynamics incorporating an external force such as gravity and heat sources. This is a multispeed model defined on a square lattice with particles that may be at rest or moving from a site to their nearest or next nearest neighbors. As usual, the collision rules for the particles conserve the number of particles and the momentum but also the energy in a non trivial way. The energy conservation law plays a relevant dynamical role making possible the simulation of thermomechanical phenomena in two-dimensional fluids. We have studied some of the equilibrium and near-equilibrium properties of this model both theoretically and by computer simulations. We present here our theoretical results and their comparison with a set of computer experiments regarding the equilibrium state, relaxation towards equilibrium and flows around simple fixed objects.