Paper Number
IN8
Session
Flow-induced Instabilities in Non-Newtonian Fluids
Title
Measuring stress and flow in asymmetric and fluctuating viscoelastic flows
Presentation Date and Time
October 12, 2022 (Wednesday) 10:10
Track / Room
Track 5 / Sheraton 2
Authors
- Pradillo, Gerardo M. (Georgetown University)
- Salipante, Paul (NIST, Polymers and Complex Fluids)
- Hudson, Steven D. (NIST, Polymers & Complex Fluids)
Author and Affiliation Lines
Gerardo M. Pradillo, Paul Salipante and Steven D. Hudson
Polymers & Complex Fluids, NIST, Gaithersburg, MD 20899
Speaker / Presenter
Salipante, Paul
Keywords
experimental methods; flow-induced instabilities; polymer solutions
Text of Abstract
Polymeric fluids with viscoelastic properties can exhibit turbulent like hydrodynamic instabilities at flow regimes where the viscous properties of the fluid motion dominate over inertial effects. While flow gradients and curvature are known to be important contributors for the onset of purely elastic instabilities, we aim to observe the relationships between stress and flow structures in unstable flow regimes. In this work, a cross-slot geometry is used to destabilize flow of a bidisperse polymeric solution. Holographic particle tracking velocimetry and birefringence polarization are simultaneously applied to elucidate the 3-D flow structures and to visualize the fluid stresses, respectively. Pressure measurements upstream of the flow cell’s center region are also obtained.