Paper Number
DP7                         My Program 

Session
Dense Particulate Systems

Title
The manifold rheology of fluidized granular media

Presentation Date and Time
October 14, 2024 (Monday) 4:05

Track / Room
Track 3 / Waterloo 5

Authors (Click on name to view author profile)

  1. D'Angelo, Olfa (Erlangen-Nürnberg University)
  2. Shetty, Abhishek (Anton Paar, Rheology)
  3. Sperl, Matthias (German Aerospace Center DLR)
  4. Kranz, Till (University of Cologne)

Author and Affiliation Lines (in printed abstract book)
Olfa D'Angelo1, Abhishek Shetty2, Matthias Sperl3 and Till Kranz4
1Erlangen-Nürnberg University, Erlangen, Germany; 2Rheology, Anton Paar, Ashland, VA 23005; 3German Aerospace Center DLR, Cologne, Germany; 4University of Cologne, Cologne, Germany

Speaker / Presenter 
D'Angelo, Olfa

Keywords
future of rheology; non-Newtonian fluids; particles; particualte systems; suspensions

Text of Abstract
Fluidized granular media have a rich rheology: measuring shear stress as a function of shear rate, they exhibit Newtonian behavior for low densities and shear rates, develop a yield stress for intermediate shear rates and densities approaching the granular glass transition, and finally, cross over to shear-thickening Bagnold scaling. This wealth of flow behaviors makes fluidized beds a fascinating material, but also one that is challenging to encompass in a global theory, despite its relevance for optimizing industrial processes and predicting natural hazards. We provide careful measurements spanning eight orders of magnitude in shear rate, and show that all these rheological regimes can be described qualitatively and quantitatively using the granular Integration Through Transient formalism, a theory for glassy dynamics under shear adapted to granular fluids. The constitutive equations’ shape is governed by the distance to the granular glass transition only.