Stresses in smooth flows of dense granular media

Author(s):
Depken, M.; Lechman, J.B.; Hecke, M.L. van (0000-0002-9550-6607); Saarloos, W. van (0000-0002-8856-8105); Grest, G.S.
Published
2007
Publication type
Article / Letter to editor

Abstract

The form of the stress tensor is investigated in smooth, dense granular flows which

are generated in split-bottom shear geometries. We find that, within a fluctuation fluidized spatial

region, the form of the stress tensor is directly dictated by the flow field: The stress and strain-rate

tensors are co-linear. The effective friction, defined as the ratio between shear and normal stresses acting on a shearing plane, is found not to be constant but to vary throughout the flowing zone. This variation cannot be explained by inertial effects, but appears to be set by the local geometry of the flow field. This is in agreement with a recent prediction, but in contrast with most models for slow grain flows, and points to there being a subtle mechanism that selects the flow profiles.

Date issued
2007
Language
English
Is part of
Europhysics Letters (2007), Vol. 78, no. 5, p. 58001
hdl
1887/66538
doi
10.1209/0295-5075/78/58001
URL
https://arxiv.org/abs/cond-mat/0611080