Mass transfer around slender drops in an extensional flow: Inertial effects at large peclet numbers

Abstract

AbstractThe exchange of mass between a slender drop and a viscous liquid in an axisymmetric extensional flow and at large Peclet numbers is examined. Four cases are discussed: an inviscid drop and a viscous drop, under both creeping flow conditions and when the external flow has a weak amount of inertia. Solutions are presented as a function of the capillary number (Ca ≫ 1), the viscosity ratio (κ ≪ 1), the external Reynolds number (Re ≪ 1), and the Peclet number (Pe ≫ 1). The results suggest that the steady mass transfer rate, to or from the slender drop, is proportional to the elongation rate to the (relative) high power of 3/2. In general, as inertia increases, the drop becomes thinner and longer, and the average tangential surface velocity and the surface area increase, resulting in larger mass transfer rates, especially near the breakup point.