2023/05/23 by Abhinendra Singh, Kuniyasu Saitoh, Singh, Abhinendra +1 · 1 citation
Engineering · Materials Science · #Adhesion, Friction, and Surface Interactions #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Geophysics (physics.geo-ph) #Granular flow and fluidized beds #Material Dynamics and Properties #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2305.14030
openalex publication_date 2023/05/23 · openalex created_date 2023/05/27 · openalex updated_date 2026/07/28
Dense suspensions often exhibit a dramatic response to large external deformation. The recent body of work has related this behavior to transition from an unconstrained lubricated to a constrained frictional state. Here, we use numerical simulations to study the flow behavior and shear-induced diffusion of frictional non-Brownian spheres in two dimensions under simple shear flow. We first show that both viscosity η and diffusivity D/γ of the particles increase at characteristic shear stress, which is associated with lubrication to frictional transition. Subsequently, we propose a one-to-one relation between viscosity and diffusivity using the length scale ξ associated with the size of collective motions (rigid clusters) of the particles. We demonstrate that η and D/γ are controlled by ξ in two distinct flow regimes, i.e. in the frictionless and frictional states, where the one-to-one relation is described as a crossover from D/γ∼η (frictionless) to η1/3 (frictional). We also confirm the proposed power laws are insensitive to the interparticle friction and system size.