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/f(alpha) noise, where alpha similar or equal to 1.32 just above, and alpha similar or equal to 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 similar or equal to 0.16, and a fractal dimension D similar or equal to 1.84.