DIFFUSE-INTERFACE METHODS IN FLUID-MECHANICS

We review the development of diffuse-interface models of hydrodynamics and their application to a wide variety of interfacial phenomena. The se models have been applied successfully to situations in which the ph ysical phenomena of interest have a length scale commensurate with the thickness of the interfacial region (e.g. near-critical interfacial p henomena or small-scale flows such as those occurring near contact lin es) and fluid flows involving large interface deformations and/or topo logical changes (e.g. breakup and coalescence events associated with f luid jets, droplets, and large-deformation waves). We discuss the issu es involved in formulating diffuse-interface models for single-compone nt and binary fluids. Recent applications and computations using these models are discussed in each case. Further, we address issues includi ng sharp-interface analyses that relate these models to the classical free-boundary problem, computational approaches to describe interfacia l phenomena, and models of fully miscible fluids.