Viscoinertial regime of immersed granular flows

Lhassan Amarsid (1, 2, 3, 4) , Jean-Yves Delenne (5) , Patrick Mutabaruka (6) , Yann Monerie (2, 7, 4) , Frédéric Perales (1, 4) , Farhang Radjai (2, 3, 4, 6)

1 IRSN - Institut de Radioprotection et de Sûreté Nucléaire
2 LMGC - Laboratoire de Mécanique et Génie Civil
3 PMMD - Physique et Mécanique des Milieux Divisés
4 MIST - Laboratoire de micromécanique et intégrité des structures
5 UMR IATE - Ingénierie des Agro-polymères et Technologies Émergentes
6 MSE 2 - Multiscale Material Science for Energy and Environment
7 ThM2 - ThermoMécanique des Matériaux

By means of extensive coupled molecular dynamics–lattice Boltzmann simulations, accounting for grain dynamics and subparticle resolution of the fluid phase, we analyze steady inertial granular flows sheared by a viscous fluid. We show that, for a broad range of system parameters (shear rate, confining stress, fluid viscosity, and relative fluid-grain density), the frictional strength and packing fraction can be described by a modified inertial number incorporating the fluid effect. In a dual viscous description, the effective viscosity diverges as the inverse square of the difference between the packing fraction and its jamming value, as observed in experiments. We also find that the fabric and force anisotropies extracted from the contact network are well described by the modified inertial number, thus providing clear evidence for the role of these key structural parameters in dense suspensions.

Mots clés: granular structure; viscous fluid; viscosity; friction

Mots clés: méthode de simulation; structure granulaire; fluide visqueux; viscosité; frottement

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Lhassan Amarsid, Jean-Yves Delenne, Patrick Mutabaruka, Yann Monerie, Frédéric Perales, et al.. Viscoinertial regime of immersed granular flows. Physical Review E , 2017, 96 (1), ⟨10.1103/PhysRevE.96.012901⟩. ⟨hal-01607197⟩