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Shear-banding predicted by a constitutive model with a structural parameter in cylindrical Couette flows
- Source :
- EPJ Web of Conferences, Vol 140, p 11003 (2017), Proceedings of Powders & Grains 2017, Powders & Grains 2017, Powders & Grains 2017, Jul 2017, Montpellier, France, Powders and Grains 2017, Powders and Grains 2017, Jul 2017, Montpellier, France
- Publication Year :
- 2017
- Publisher :
- EDP Sciences, 2017.
-
Abstract
- International audience; Dense suspensions of non-Brownian particles may partially behave as thixotropic yield stress fluids. We study the flow of such fluids between two concentric cylinders using a phenomenological structural kinetics model. The structural kinetics approach balances the simplicity of phenomenological continuum approaches with a simplified model for structure against the complexity a more fundamental model based on particle micromechanics. A modified version of Houska's model, which includes a diffusive term for the structural parameter, is considered. Depending on the breakdown rate of the structural parameter, shear-banding may be observed. For shear-banding in steady flows, the stress selection depends on the diffusion of the structural parameter. If there is no structural diffusion, the displacement of the interface between the flowing and the static regions fixes the stress at the interface during the transient flow. In the cases of very small diffusive coefficients, the stress at the fluid / solid interface converges to a limit value which is different from the yield stress of the structured material as expected without any diffusion. Nevertheless, the inner torque and the flow profile are quite similar in both cases and the differences are localized near the fluid / solid interface. For shear-banding, the gradients of the structural parameter and the strain rate are very abrupt but the continuity is preserved by the diffusion.
- Subjects :
- [PHYS.PHYS.PHYS-FLU-DYN]Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn]
Thixotropy
Materials science
010304 chemical physics
Limit value
Physics
QC1-999
Constitutive equation
Kinetics
Micromechanics
Mechanics
[PHYS.PHYS.PHYS-FLU-DYN] Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn]
Strain rate
01 natural sciences
Physics::Fluid Dynamics
Shear (geology)
0103 physical sciences
Torque
[PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph]
Statistical physics
[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph]
010306 general physics
ComputingMilieux_MISCELLANEOUS
Subjects
Details
- Language :
- English
- Volume :
- 140
- Database :
- OpenAIRE
- Journal :
- EPJ Web of Conferences
- Accession number :
- edsair.doi.dedup.....89cee95073fb33cf017512ce03582cee