Domain growth in computer simulations of segregating two-dimensional binary fluids

We studied phase segregation kinetics with hydrodynamic interactions, following a quench, in the two-dimensional binary fluid lattice gas model of Rothman and Keller. Carrying out computer simulations at different overall fluid densities d, with equal volume fractions of the two components, we find that the growth of domain sizes R(t) at different d has a scaling behavior with all data well fitted by R(t)/${\mathit{R}}_{\mathit{s}}$=a+b(t/${\mathit{t}}_{\mathit{s}}$ ${)}^{2/3}$. The characteristic lengths ${\mathit{R}}_{\mathit{s}}$(d) and times ${\mathit{t}}_{\mathit{s}}$(d) are related in a simple way to the viscosity and surface tension of the system at different values of d. We also discuss the growth exponents expected in the general case of phase segregation with hydrodynamic interactions.