While lattice gas models have had some success in simulating fluid behaviour
they have a number of draw backs. One of these is the noise which is
inherent in a lattice gas model. This is due to the limited number of sites
over which the averaging takes placer
to find the macroscopic variables 
and
. Another problem is the number of states which
need to be considered during the collision stage. For a two-dimensional model
such as the FHP-III this is fairly small since each in-state
has a maximum of
two possible outcomes and a look-up table with
entries is required. For a three-dimensional simulation a
table as large as 
may be required. The Galilean
invariance problem is a major draw back of the lattice gas scheme.
It can be overcome using a scaling technique for single fluid flows
with a slowly varying density. This is not possible for multi-phase
simulations. The density-dependence of the transport coefficients is another
feature of the lattice gas models which restricts their use to constant
density situations.