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arXiv · 1411.3215

Heaping, Secondary Flows and Broken Symmetry in Flows of Elongated Granular Particles

Geert Wortel·Tamás Börzsönyi·Ellák Somfai·Sandra Wegner·Balázs Szabó·Ralf Stannarius·Martin van Hecke
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Abstract

In this paper we report experiments where we shear granular rods in split-bottom geometries, and find that a significant heap of height of least 40% of the filling height can form at the particle surface. We show that heaping is caused by a significant secondary flow, absent for spherical particles. Flow reversal transiently reverses the secondary flow, leading to a quick collapse and slower regeneration of the heap. We present a symmetry argument and experimental data that show that the generation of the secondary flow is driven by a misalignment of the mean particle orientation with the streamlines of the flow. This general mechanism is expected to be important in all flows of sufficiently anisometric grains.

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Geert Wortel, Tamás Börzsönyi, Ellák Somfai, Sandra Wegner, Balázs Szabó, Ralf Stannarius, Martin van Hecke. 2015-02-10. Heaping, Secondary Flows and Broken Symmetry in Flows of Elongated Granular Particles. https://doi.org/10.1039/c4sm02534b

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