Paper Number
IN7 

Session
Flow-induced Instabilities and Non-Newtonian Fluids

Title
Unification of the rheological physics of yield stress fluids

Presentation Date and Time
October 12, 2021 (Tuesday) 4:10

Track / Room
Track 4 / Meeting Room C-D

Authors (Click on name to view author profile)

  1. Kamani, Krutarth M. (University of Illinois at Urbana-Champaign, Department of Chemical and Biomolecular Engineering)
  2. Donley, Gavin J. (Georgetown University, Physics)
  3. Rogers, Simon A. (University of Illinois at Urbana-Champaign, Department of Chemical and Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Krutarth M. Kamani1, Gavin J. Donley2 and Simon A. Rogers1
1Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801; 2Physics, Georgetown University, Washington DC, DC 20057

Speaker / Presenter 
Kamani, Krutarth M.

Keywords
theoretical methods; additive manufacturing; colloids; emulsions; foams; gels; glasses; non-Newtonian fluids

Text of Abstract
The physics above and below the yield stress is unified by a simple model for viscoplasticity that accounts for the nonlinear rheology of multiple yield stress fluids. The model has a rate-dependent relaxation time, allows for plastic deformation below the yield stress, and indicates that rapid elastic deformation aids yielding. All parameters are obtained from a linear-regime frequency sweep and a steady-shear flow curve. A range of commonly observed rheological behaviors are predicted, including avalanches and viscosity bifurcations, yield strains, the smooth overshoot in the loss modulus and the recently discovered contributions from recoverable and unrecoverable strains in amplitude sweeps.