Microscopic Description of the Granular Fluidity Field in Nonlocal Flow Modeling

A recent granular rheology based on an implicit "granular fluidity" field has been shown to quantitatively predict many nonlocal phenomena. However, the physical nature of the field has not been identified. Here, the granular fluidity is found to be a kinematic variable given by the veloci...

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Bibliographic Details
Main Authors: Zhang, Qiong, Kamrin, Ken, Kamrin, Kenneth N
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering
Format: Article
Published: American Physical Society (APS) 2018
Online Access:http://hdl.handle.net/1721.1/117654
https://orcid.org/0000-0002-3856-6902
https://orcid.org/0000-0002-5154-9787
Description
Summary:A recent granular rheology based on an implicit "granular fluidity" field has been shown to quantitatively predict many nonlocal phenomena. However, the physical nature of the field has not been identified. Here, the granular fluidity is found to be a kinematic variable given by the velocity fluctuation and packing fraction. This is verified with many discrete element simulations, which show that the operational fluidity definition, solutions of the fluidity model, and the proposed microscopic formula all agree. Kinetic theoretical and Eyring-like explanations shed insight into the obtained form.