Dynamics of Drop Deformation and Breakup in Viscous Fluids

This article describes the dynamics of drop deformation and breakup in viscous flows at low Reynolds numbers. An attempt has been made to bring together a wide range of studies in the drop deformation literature, as well as to provide a large number of references to potential applications. In particular, a summary is provided of experimental, numerical, and theoretical investigations that examine drop breakup in externally­ imposed flows, e.g. uniaxial extensional fluid motion or more complicated time-periodic flows. For well-characterized flow conditions that lead to breakup, the effects of flow and material parameters on the drop size distribution are summarized. Also, a short discussion is given of the stability of the shapes of translating drops. The subject of deformation of neutrally buoyant drops in viscous shear flows at low particle Reynolds numbers was summarized by Acrivos ( 1983) and was reviewed in this series by Rallison ( 1 984). The Acrivos and Rallison papers present (a) theoretical descriptions of steady, nearly spheri­ cal shapes and steady, long slender shapes, (b) a description of efficient boundary integral numerical methods, and (e) a summary of the experi­ mental work performed prior to 1984. As documented in these review articles, many of the important ideas necessary for understanding drop