Experimental evidence of density fluctuations in two-dimensional bins

Abstract

We have found experimentally the existence of random density fluctuations, during the discharge of monodisperse granular material from flat bins, which follows a 1/fα noise, where α reverse similar, equals 1.32 just above, and α reverse similar, equals 1.0 just below the exit of the bin. The corresponding rescaled range analysis for the fractal noise obtained just above the exit gives a Hurst parameter H reverse similar, equals 0.16, and a fractal dimension D reverse similar, equals 1.84.