Vesicle dynamics in large amplitude oscillatory extensional flow
نویسندگان
چکیده
Although the behaviour of fluid-filled vesicles in steady flows has been extensively studied, far less is understood regarding shape dynamics time-dependent oscillatory flows. Here, we investigate nonlinear large amplitude extensional (LAOE) using both experiments and boundary integral (BI) simulations. Our results characterize transient membrane deformations, dynamical regimes stress response LAOE terms reduced volume (vesicle asphericity), capillary number ( ${Ca}$ , dimensionless flow strength) Deborah ${De}$ frequency). Results from single vesicle are found to be good agreement with BI simulations across a wide range parameters. reveal three distinct based on deformation: pulsating, reorienting symmetrical regimes. We construct phase diagrams characterizing transition shapes between within two-dimensional Pipkin space defined by . Contrary observations clean Newtonian droplets, do not reach maximum length twice per strain rate cycle pulsating The observed each regime result competition frequency, time scale deformation scale. By calculating particle stresslet, quantify relationship average rate. Additionally, present tubular that undergo transformation over several cycles. Broadly, our work provides new information directly informs bulk suspension rheology.
منابع مشابه
Single polymer dynamics under large amplitude oscillatory extension
Yuecheng Zhou1 and Charles M. Schroeder1,2,3,* 1Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA 2Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA 3Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, I...
متن کاملDynamics of melting and recrystallization in a polymeric micellar crystal subjected to large amplitude oscillatory shear flow.
Shear-induced structural transitions of a micellar cubic phase during large amplitude oscillatory shear flow is studied with time-resolved oscillatory rheological small angle neutron scattering. This technique allows us to resolve the structural changes within a cycle of oscillation. By applying a strain rate near the critical melting shear rate, melting and recrystallization occurs in a cyclic...
متن کاملFourier decomposition of polymer orientation in large-amplitude oscillatory shear flow
In our previous work, we explored the dynamics of a dilute suspension of rigid dumbbells as a model for polymeric liquids in large-amplitude oscillatory shear flow, a flow experiment that has gained a significant following in recent years. We chose rigid dumbbells since these are the simplest molecular model to give higher harmonics in the components of the stress response. We derived the expre...
متن کاملTransient and Average Unsteady Dynamics of Single Polymers in Large-Amplitude Oscillatory Extension
Oscillatory rheometry has been widely used in bulk rheological measurements of complex fluids such as polymer solutions and melts. Despite recent progress on bulk oscillatory rheology, however, the vast majority of single polymer studies has focused on chain dynamics in simple on/ off step strain-rate experiments. In order to fully understand dynamic polymer microstructure and to establish conn...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Fluid Mechanics
سال: 2021
ISSN: ['0022-1120', '1469-7645']
DOI: https://doi.org/10.1017/jfm.2021.885