Orientational arrest in dense suspensions of elliptical particles under oscillatory shear flows
Yousefian, Zakiyeh LU and Trulsson, Martin LU
(2021)
In EPL
136(3).
- Abstract
We study the rheological response of dense suspensions of elliptical particles, with an aspect ratio equal to 3, under oscillatory shear flows and imposed pressure by numerical simulations. Like for the isotropic particles, we find that the oscillatory shear flows respect the Cox-Merz rule at large oscillatory strains but differ at low strains, with a lower viscosity than the steady shear and higher shear jamming packing fractions. However, unlike the isotropic cases (i.e., discs and spheres), frictionless ellipses get dynamically arrested in their initial orientational configuration at small oscillatory strains. We illustrate this by starting at two different configurations with different nematic order parameters and the average... (More)
We study the rheological response of dense suspensions of elliptical particles, with an aspect ratio equal to 3, under oscillatory shear flows and imposed pressure by numerical simulations. Like for the isotropic particles, we find that the oscillatory shear flows respect the Cox-Merz rule at large oscillatory strains but differ at low strains, with a lower viscosity than the steady shear and higher shear jamming packing fractions. However, unlike the isotropic cases (i.e., discs and spheres), frictionless ellipses get dynamically arrested in their initial orientational configuration at small oscillatory strains. We illustrate this by starting at two different configurations with different nematic order parameters and the average orientation of the particles. Surprisingly, the overall orientation in the frictionless case is uncoupled to the rheological response close to jamming, and the rheology is only controlled by the average number of contacts and the oscillatory strain. Having larger oscillatory strains or adding friction does, however, help the system escape these orientational arrested states, which are evolving to a disordered state independent of the initial configuration at low strains and ordered ones at large strains.
(Less)
- author
- Yousefian, Zakiyeh
LU
and Trulsson, Martin
LU
- organization
- publishing date
- 2021-11
- type
- Contribution to journal
- publication status
- published
- subject
- in
- EPL
- volume
- 136
- issue
- 3
- article number
- 36002
- publisher
- EDP Sciences
- external identifiers
-
- scopus:85126532724
- ISSN
- 0295-5075
- DOI
- 10.1209/0295-5075/ac3e8a
- language
- English
- LU publication?
- yes
- id
- fd0d54d6-62f1-4282-935b-07c4a080c5a8
- date added to LUP
- 2022-05-02 15:06:01
- date last changed
- 2025-04-04 14:04:44
@article{fd0d54d6-62f1-4282-935b-07c4a080c5a8,
abstract = {{<p>We study the rheological response of dense suspensions of elliptical particles, with an aspect ratio equal to 3, under oscillatory shear flows and imposed pressure by numerical simulations. Like for the isotropic particles, we find that the oscillatory shear flows respect the Cox-Merz rule at large oscillatory strains but differ at low strains, with a lower viscosity than the steady shear and higher shear jamming packing fractions. However, unlike the isotropic cases (i.e., discs and spheres), frictionless ellipses get dynamically arrested in their initial orientational configuration at small oscillatory strains. We illustrate this by starting at two different configurations with different nematic order parameters and the average orientation of the particles. Surprisingly, the overall orientation in the frictionless case is uncoupled to the rheological response close to jamming, and the rheology is only controlled by the average number of contacts and the oscillatory strain. Having larger oscillatory strains or adding friction does, however, help the system escape these orientational arrested states, which are evolving to a disordered state independent of the initial configuration at low strains and ordered ones at large strains.</p>}},
author = {{Yousefian, Zakiyeh and Trulsson, Martin}},
issn = {{0295-5075}},
language = {{eng}},
number = {{3}},
publisher = {{EDP Sciences}},
series = {{EPL}},
title = {{Orientational arrest in dense suspensions of elliptical particles under oscillatory shear flows}},
url = {{http://dx.doi.org/10.1209/0295-5075/ac3e8a}},
doi = {{10.1209/0295-5075/ac3e8a}},
volume = {{136}},
year = {{2021}},
}