Document Type
Article
Publication Date
2009
Publication Title
Philosophical Transactions of the Royal Society
Abstract
We have made measurements of force and velocity fluctuations in a variety of dense, gravity-driven granular flows under flow conditions close to the threshold of jamming. The measurements reveal a microscopic state that evolves rapidly from entirely collisional to largely frictional, as the system is taken close to jamming. On coarse-grained time scales, some descriptors of the dynamics—such as the probability distribution of force fluctuations, or the mean friction angle—do not reflect this profound change in the micromechanics of the flow. Other quantities, such as the frequency spectrum of force fluctuations, change significantly, developing low-frequency structure in the fluctuations as jamming is approached. We also show evidence of spatial structure, with force fluctuations being organized into local collision chains. These local structures propagate rapidly in the flow, with consequences far away from their origin, leading to long-range correlations in velocity fluctuations.
Keywords
granular flow, jamming, force chains
Volume
367
First Page
5109
Last Page
5121
DOI
10.1098/rsta.2009.0189
Rights
© 2009 The Royal Society
Recommended Citation
Gardel, Emily; Seitaridou, E.; Facto, Kevin; Keene, E.; Hattam, K.; Easwar, Nalini; and Menon, Narayanan, "Dynamical Fluctuations in Dense Granular Flows" (2009). Physics: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/phy_facpubs/46
Comments
Archived as published.