%0 Journal Article
%T Wall roughness and nonlinear velocity profiles in granular shear flows
%+ Physique et Mécanique des Milieux Divisés (PMMD)
%+ Laboratoire de Mécanique et Technologie (LMT)
%A Schuhmacher, Paul
%A Radjai, Farhang
%A Roux, Stéphane
%< avec comité de lecture
%@ 2100-014X
%J EPJ Web of Conferences
%I EDP Sciences
%V 140
%P 03090
%8 2017
%D 2017
%R 10.1051/epjconf/201714003090
%Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph]
%Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph]
%Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph]
%Z Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph]Journal articles
%X Inhomogeneous velocity profiles in granular flows are well known from both experiments and simulations, and considered as a hallmark of nonlocal behavior. By means of extensive contact dynamics simulations , we show that the sigmoidal velocity profiles in 2D flows of rigid disks are controlled by the roughness of driving boundary walls. We find that the velocity profile becomes linear for a critical value of wall roughness up to an exponential decay close to the walls with a characteristic length that does not depend on the flow thickness and rate. We describe the velocity profiles by introducing a state parameter that carries wall perturbation. By assuming that the local shear rate is a linear function of the state parameter, we obtain an analytical expression that fits velocity profiles. In this model, the nonlinear velocity profiles are explained in terms of the effects of wall roughness as boundary condition for the state parameter.
%G English
%2 https://hal.science/hal-01985872/document
%2 https://hal.science/hal-01985872/file/Art_Radjai_al_EPJ_P%26G_2017.pdf
%L hal-01985872
%U https://hal.science/hal-01985872
%~ CNRS
%~ ENS-CACHAN
%~ LMGC
%~ LMT
%~ UNIV-PARIS-SACLAY
%~ ENS-CACHAN-SACLAY
%~ MIPS
%~ UNIV-MONTPELLIER
%~ SORBONNE-UNIVERSITE
%~ SU-SCIENCES
%~ LMT-SACLAY
%~ SU-TI
%~ FARMAN
%~ ENS-PARIS-SACLAY
%~ GS-ENGINEERING
%~ ALLIANCE-SU
%~ LMPS
%~ UM-2015-2021