Rheology of dense granular flows for elongated particles

Abstract

We study the rheology of dense granular flows for frictionless spherocylinders by means of 3D numerical simulations. As in the case of spherical particles, the effective friction $\mu$ is an increasing function of the inertial number $I$, and we systematically investigate the dependence of $\mu$ on the particle aspect ratio $Q$, as well as that of the normal stress differences, the volume fraction and the coordination number. We show in particular that the quasi-static friction coefficient is non-monotonic with $Q$: from the spherical case $Q=1$, it first sharply increases, reaches a maximum around $Q\simeq 1.05$, and then gently decreases, reaching back its initial value for $Q\simeq 2$. We provide a microscopic interpretation for this unexpected behavior through the analysis of the distribution of dissipative contacts around the particles: as compared to spheres, slightly elongated grains enhance contacts in their central cylindrical band, whereas at larger aspect ratios particles tend to align and dissipate by preferential contacts at their hemispherical caps.

5 pages, 5 figures

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Cited by in corpus (9)

• Flow and rheology of frictional elongated grains
• Discharge of elongated grains from silo with rotating bottom
• Shear thickening of suspensions of dimeric particles
• Exploring noisy Jeffery orbits: A combined Fokker-Planck and Langevin analysis in 2D and 3D
• Transverse vortices induced by modulated granular shear flows of elongated particles
• Orientational arrest in dense suspensions of elliptical particles under oscillatory shear flows
• Dynamic Phases and Combing Effects for Elongated Particles Moving Over Quenched Disorder
• Collective alignment controls rotation frustration in granular flows of elongated particles
• Shear flow of frictional spheroids: Comparison between elongated and flattened particles