EPJ Web Conf.
Volume 140, 2017Powders and Grains 2017 – 8th International Conference on Micromechanics on Granular Media
|Number of page(s)||4|
|Published online||30 June 2017|
Dense flow around a sphere moving into a cloud of grains
1 Laboratoire FAST, Université Paris-Sud, CNRS, Université Paris-Saclay, F-91405, Orsay, France
2 LMO, CNRS, Université Paris-Sud, Université Paris-Saclay, F-91405, Orsay, France
3 CMAP, CNRS, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau, France
4 SPHYNX/SPEC, CEA, CNRS, Université Paris-Saclay, F-91191, Gif-sur-Yvette, France
* e-mail: email@example.com
Published online: 30 June 2017
A bidimensional simulation of a sphere moving at constant velocity into a cloud of smaller spherical grains without gravity is presented with a non-smooth contact dynamics method. A dense granular “cluster” zone of about constant solid fraction builds progressively around the moving sphere until a stationary regime appears with a constant upstream cluster size that increases with the initial solid fraction ϕ0 of the cloud. A detailed analysis of the local strain rate and local stress fields inside the cluster reveals that, despite different spatial variations of strain and stresses, the local friction coeffcient μ appears to depend only on the local inertial number I as well as the local solid fraction ϕ, which means that a local rheology does exist in the present non parallel flow. The key point is that the spatial variations of I inside the cluster does not depend on the sphere velocity and explore only a small range between about 10−2 and 10−1. The influence of sidewalls is then investigated on the flow and the forces.
© The Authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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