Numerical study on the effect of rheological parameters on the droplet deformation process in Newtonian and non-Newtonian two-phase systems using extended finite element method

Abstract

In the present study, attempts were made to study the effect of rheological parameters on the drop deformation process. For this purpose, both Newtonian and non-Newtonian (Carreau-Yasuda model) were considered and extended finite element method (XFEM) along with level-set method (LSM) were used to simulate the process. The result showed that in Newtonian-Newtonian systems, there was no shear stress overshoot (maximum) during the deformation process and the shear stress increased monotonically until it reached a steady-state, whereas, it exhibited an overshoot (maximum) for non-Newtonian systems. Results also showed that the increase of the wall confinement parameter (R/H) would increase the droplet deformation monotonically for studied viscosity ratios. It was further observed that the steady-state deformation parameter (Dss) was increased as Ca increased from 0.2 to 0.8 for viscosity ratio (λ) between 0.5 and 2.5.