FRACTIONAL PROPAGATION AND THE ELIMINATION OF STAGGERED INVARIANTS INLATTICE-BGK MODELS

Lattice-based models have been attracting much interest in recent year s and have been applied to many complex systems. The derivation of lar ge scale dynamical equations of lattice-gas models as well as lattice- Boltzmann models was based on the belief that only the physically inte resting quantities (mass, momentum and energy) are conserved. Staggere d invariants in lattice-gas models were found in 1988 and there have b een no efficient methods to eliminate these invariants. In this paper, we will first discuss the existence of staggered invariants, then we propose to use fractional propagation as an effective way of suppressi ng these undesired invariants. Numerical simulations will be used to c onfirm the theory and to show the improvement of computations.