Anomalous transport in conical granular piles

Abstract

Experiments on 2+1-dimensional piles of elongated particles are performed. Comparison with previous experiments in 1+1 dimensions shows that the addition of one extra dimension to the dynamics changes completely the avalanche properties, with the appearance of a characteristic avalanche size. Nevertheless, the time which single grains need to cross the whole pile varies smoothly between several orders of magnitude, from a few seconds to more than 100 hours. This behavior is described by a power-law distribution, signaling the existence of scale invariance in the transport process.

25 Years of Self-organized Criticality: Concepts and Controversies

“…Interestingly, the ricepile experiment (Frette et al, 1996) and the ricepile or Oslo model (Christensen et al, 1996) both fared much better in that respect. As far as granular media is concerned, the Oslo model has probably the best experimental support (Frette et al, 1996;Ahlgren et al, 2002;Aegerter et al, 2003;Lőrincz and Wijngaarden, 2007).…”

Granular materials composed of shape-anisotropic grains

“…9) have attracted a lot of attention over the past two decades. 20,[120][121][122] The motivation for these studies was to check the validity of Self-Organized Criticality (SOC), introduced by Bak, Tang and Wiesenfeld, 3 for strongly nonspherical grains. Various materials have been studied including rice, 20,121,122 lentils, quinoa, and mung beans.…”

“…The motivation for these studies was to check the validity of Self Organized Criticality (SOC), introduced by Bak, Tang and Wiesenfeld [3], for strongly nonspherical grains. Various materials have been studied including rice [20,121,122], lentils, quinoa, and mung beans [122]. These studies re-vealed that only the behavior of long grain rice piles complied the criteria for SOC, namely a power-law shaped avalanche size distribution, finite size scaling, and a universal scaling relation with certain characteristic exponents.…”

“…Surface avalanches on granular heaps consisting of elongated grains (Fig. 9) have attracted a lot of attention with the past two decades [20,[120][121][122]. The motivation for these studies was to check the validity of Self Organized Criticality (SOC), introduced by Bak, Tang and Wiesenfeld [3], for strongly nonspherical grains.…”