Lattice gas models for 3D hydrodynamics

The 3D Navier-Stokes equations are obtained from two different lattice gas models. The first one has its sites on a cubic lattice and has particle speeds zero, one and √2. The second one is a 3D projection of a lattice gas implementation of the 4D Navier-Stokes equations, residing on a face-centred hypercubic lattice.