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arXiv · 2608.04168

Role of Particle Shape in Strain-Controlled Resuspension of Dense Suspensions

Mohammadreza Mahmoudian·Mahdi Vaezi·Parisa Mirbod
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Abstract

> Dense non-Brownian suspensions exhibit complex resuspension dynamics governed by hydrodynamic interactions, particle microstructure, and gravity. While viscous resuspension in spherical suspensions is known to be strain-controlled, its applicability to anisotropic particles remains unclear. Here, we investigate dense suspensions of spherical and rod-shaped particles under steady and oscillatory shear. The results reveal two strain-controlled transitions: particle detachment from the sediment bed and the transition to a fully suspended state. Both particle shapes exhibit the same critical strain for detachment, approximately 6, indicating that resuspension onset is largely independent of particle morphology. In contrast, complete resuspension requires a critical strain of approximately 120 for spheres and 180 for rods, demonstrating a strong effect of particle anisotropy. A fluid-strain scaling collapses the onset of resuspension across particle concentrations and shapes while highlighting the distinct influence of particle shape on complete suspension. These findings establish a unified strain-based framework for viscous resuspension and clarify the role of particle anisotropy in dense suspension dynamics.

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Mohammadreza Mahmoudian, Mahdi Vaezi, Parisa Mirbod. 2026-08-04. Role of Particle Shape in Strain-Controlled Resuspension of Dense Suspensions. https://arxiv.org/abs/2608.04168

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