Paper Number
NF2
Session
Non-Newtonian Fluid Mechanics & Flow Instabilities
Title
Effect of confinement on velocity profiles in pressure driven flow of wormlike micelle solutions
Presentation Date and Time
October 16, 2018 (Tuesday) 10:15
Track / Room
Track 7 / Plaza II
Authors
- Salipante, Paul F. (National Institute of Standards and Technology, Polymers and Complex Fluids Group)
- Hudson, Steven (NIST, Polymers and Complex Fluids Group)
Author and Affiliation Lines
Paul F. Salipante and Steven Hudson
Polymers and Complex Fluids Group, National Institute of Standards and Technology, Gaithersburg, MD 20910
Speaker / Presenter
Salipante, Paul F.
Text of Abstract
We investigate the effect of confinement on the velocity profiles of shear banding wormlike micelle solutions in pressure driven capillary flow. Velocity profiles are obtained using holographic 3d particle tracking velocimetry on the fluids seeded with microparticles. The velocity profiles measured at different volumetric flow rates are compared to expected velocity profiles determined from rotational rheometry. Capillary rheology measurements are performed simultaneously via measurements of flow rate and pressure drop across the capillary. While capillary rheology measurements yield viscosity values consistent with rotational rheometry, we observe deviation between the measured and expected velocity profiles that becomes more significant as the flow rate increases. We attribute the deviation to the finite interfacial width between the two shear bands. We compare our flow profile results to theoretical models that include nonlocal terms to describe the interfacial contribution to the total stress.