Scale-free channeling patterns near the onset of erosion of sheared granular beds.

ABSTRACT: Erosion shapes our landscape and occurs when a sufficient shear stress is exerted by a fluid on a sedimented layer. What controls erosion at a microscopic level remains debated, especially near the threshold forcing where it stops. Here we study, experimentally, the collective dynamics of the moving particles, using a setup where the system spontaneously evolves toward the erosion onset. We find that the spatial organization of the erosion flux is heterogeneous in space and occurs along channels of local flux σ whose distribution displays scaling near threshold and follows [Formula: see text], where J is the mean erosion flux. Channels are strongly correlated in the direction of forcing but not in the transverse direction. We show that these results quantitatively agree with a model where

SUBMITTER: Aussillous P 

PROVIDER: S-EPMC5081627 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature