Rheology of Suspensions of Flat Elastic Particles
Jens Eggers1, Tanniemola B Liverpool1, Alexander Mietke1
1School of Mathematics, University of Bristol, Fry Building, Bristol BS8 1UG, United Kingdom.
Physical Review Letters
|November 24, 2023
Summary
This study models flat elastic particles in fluid, finding their rheological response resembles classical dumbbell models in strong flows. This provides new insights into complex fluid dynamics.
Area of Science:
- Fluid dynamics
- Rheology
- Polymer physics
Background:
- Understanding the behavior of complex fluids with non-spherical particles is crucial.
- Existing models often simplify particle shapes, limiting applicability.
- Flat elastic particles present unique rheological challenges.
Purpose of the Study:
- To develop a constitutive model for suspensions of noninteracting flat elastic particles.
- To investigate the rheological response of these suspensions under flow.
- To compare the findings with established fluid dynamics models.
Main Methods:
- Modeling flat particles as three connected beads with nonlinear springs.
- Solving stochastic equations of motion exactly using Stokes law.
- Calculating the stress tensor for the particle suspension.
Main Results:
- A constitutive law for the stress tensor was derived.
- A lower convected time derivative naturally emerged in the model.
- The rheological response in strong extensional and contracting flows matched the Oldroyd-B model.
Conclusions:
- The developed model accurately captures the behavior of flat elastic particle suspensions.
- The surprising similarity to the Oldroyd-B model offers a new perspective on complex fluid rheology.
- This work advances the understanding of non-Newtonian fluid mechanics.
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