Effects of Viscoelasticity on Drop Deformation in Shear Flows

A three dimensional front tracking finite difference method is used to study the deformation of a Newtonian drop suspended in an Oldroyd-B fluid undergoing a steady shearing motion. The change in drop deformation and orientation with increasing Deborah number is established for small to moderate deformations and explained by examining the elastic and viscous stresses at the interface. Significant change in the drop orientation with the flow direction, with increasing viscoelasticity is observed. A non-monotonic change in steady state drop deformation is observed with increasing Deborah number and explained in terms of the competition between increase due to localized polymer stretching at the drop tips and decrease due to change in drop orientation angle.