Title: 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
Authors: Mohammad Ali Moeeni; Mahdi Salami Hosseini; Mir Karim Razavi Aghjeh; Mehdi Mostafaiyan
Addresses: Institute of Polymeric Materials, Sahand University of Technology, Sahand New Town, Tabriz, Iran ' Institute of Polymeric Materials; Faculty of Polymer Engineering, Sahand University of Technology, Sahand New Town, Tabriz, Iran ' Institute of Polymeric Materials, Sahand University of Technology, Sahand New Town, Tabriz, Iran ' Leibniz Institute for Polymer Research, Dresden University of Technology, Dresden, Germany
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.
Keywords: extended finite element method; XFEM; droplet deformation; viscosity ratio; Newtonian fluid; non-Newtonian fluid.
Progress in Computational Fluid Dynamics, An International Journal, 2020 Vol.20 No.3, pp.143 - 155
Received: 06 Sep 2018
Accepted: 07 Jul 2019
Published online: 05 May 2020 *