Growth kinetics for a model two-dimensional fluid

We present a numerical study of a simple Langevin-equation model for spinodal decomposition in a two-dimensional fluid. The model is characterized by a conserved scalar density coupled through the continuity equation to a conserved current. The current obeys a generalized Navier-Stokes equation with a noise term. Our results show that the system exhibits scaling behavior at long times after a quench into the ordered part of the phase diagram, and that the domain size increases as the square root of time at the longest times studied, in agreement with theoretical expectations and molecular-dynamics results.