Mercredi 17 juin 2026 à 11h salle 357 ; IUSTI
Abstract: Dense granular flows composed of elongated particles exhibit a strong frustration of particle rotation compared with spherical grains, yet the mechanisms responsible for this effect remain unclear. In this seminar, I will present results from 3D discrete element simulations of dense, confined shear flows, aimed at elucidating the origin of this rotational frustration. I will show that this inhibition cannot be explained by particle shape, friction, or solid fraction alone. Rather, it appears to be primarily governed by the degree of collective alignment that develops under shear. Building on this observation, I will propose a simple scaling law relating the average particle angular velocity to the local shear rate through a hampering parameter that depends exclusively on the degree of orientational order, quantified by a nematic order parameter.