Numerical Investigation of the Influence of Viscoelasticity on Drop Deformation in Shear

Abstract

Numerical simulations and experimental data are compared for the investigation of the influence of viscoelasticity on drop deformation in shear. A viscoelastic drop suspended in a Newtonian liquid, or a Newtonian drop suspended in a viscoelastic liquid, is sheared and investigated for transients, relaxation after cessation of shear flow, and step‐up in shear rate. The numerical simulations are conducted at parameters chosen to model the experiments. We use the volume of fluid (VOF) continuum surface force (CSF) algorithm for situations dominated by shear. For drop relaxation experiments, we use the paraboloid representation of the interface in the surface tension force (PROST) algorithm. The Oldroyd‐B and Giesekus constitutive models are implemented. An interesting result is that by stepping up in the capillary number gradually, a stationary states is achieved at higher capillary numbers than without the graduated steps. The experimental work is described in Verhulst, Moldenaers and Cardinaels [l]. We present a summary of the numerical approach here. The reader is referred to [2] for details.