Phase separation in a chaotic flow

The phase separation between two immiscible liquids advected by a bidimensi onal velocity field is investigated numerically by solving the correspondin g Cahn-Hilliard equation. We study how the spinodal decomposition process d epends on the presence-or absence-of Lagrangian chaos. A fully chaotic how, in particular, limits the growth of domains, and for unequal volume fracti ons of the liquids, a characteristic exponential distribution of droplet si zes is obtained. The limiting domain size results from a balance between ch aotic mixing and spinodal decomposition, measured in terms of Lyapunov expo nent and diffusivity constant, respectively.