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arXiv · 2211.12272

Non-monotonic Rheology and Stress Heterogeneity in confined Granular suspensions

Haitao Hu·Yiqiu Zhao·Weiwei Zhao·Ligen Qiao·Qin Xu
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Abstract

We systematically investigated the impact of boundary confinement on the shear-thickening rheology of dense granular suspensions. Under highly confined conditions, dense suspensions were found to exhibit size-dependent or even rarely reported non-monotonic ($S$-shaped) flow curves in steady states. By performing in-situ boundary stress microscopy measurements, we observed enhanced flow heterogeneities in confined suspensions, where concentrated high-stress domains propagated stably either along or against the shear direction. By comparing the boundary stress microscopy results with macroscopic flow responses, we revealed the connection between non-monotonic rheology and stress heterogeneity in confined suspensions. These findings suggest the possibility of controlling suspension rheology by imposing different boundary confinements.

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Haitao Hu, Yiqiu Zhao, Weiwei Zhao, Ligen Qiao, Qin Xu. 2022-11-22. Non-monotonic Rheology and Stress Heterogeneity in confined Granular suspensions. https://doi.org/10.1122/8.0000889

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