Nonlocal effects in the shear banding of a thixotropic yield stress fluid

We observe a novel type of shear banding in the rheology of thixotropic yield-stress fluids that is due to the coupling of both non-locality and thixotropy. The latter is known to lead to shear banding even in homogeneous stress fields, but the bands observed in the presence of non-local effects appear different as the shear rate varies continuously over the shear band. Here, we introduce a simple non-local model for the shear banding (NL-SB), and we implement it for the analysis of micron-scale rheo-MRI velocimetry measurements of a milk microgel suspension in a cone-and-plate geometry. The proposed NL-SB model accurately quantifies the cooperativity length and yields values in the order of the aggregate size in the microgel.

Subjects

Physics - Soft Condensed Matter

DDC Class

530: Physics

Lizenz

https://creativecommons.org/licenses/by/4.0/

Name

PhysRevFluids.6.113301.pdf

Type

Main Article

Size

2.04 MB

Format

Adobe PDF

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Nonlocal effects in the shear banding of a thixotropic yield stress fluid