Experimental observations of oscillations and segregation in a binary granular mixture

Abstract

We present experimental evidence for a "granular clock." We use a setup in which vertical vibrations (10-20 Hz) of a bidisperse granular medium cause horizontal oscillations (periods in the order of minutes) between two connected compartments. Moreover, we present the first experimental evidence for full segregation of smaller particles into one compartment, leaving the larger ones in the other compartment. Simulations, using a simple model, describe phenomenologically the observed oscillations.

A minimal mechanical device displaying bona fide stochastic resonance

“…1 Except for this tilted bottom, the box has the same shape as the shaken, compartmentalized box that has been used to demonstrate asymmetric clustering [25,26] and periodical oscillations [27] of an ensemble of spheres, instead of just one sphere.…”

Flux measurement in compartmentalized mono-disperse and bi-disperse granular gases

“…Li · R. Liu · M. Shinde · M. Hou (B) Institute of Physics, Chinese Academy of Sciences, Beijing, China e-mail: mayhou@aphy.iphy.ac.cn kelsen et al [7,8] studied a competitive clustering phenomenon with two types of particles different in sizes and masses. With a proper shaking strength, a so-called "granular clock" phenomenon was observed both in simulations [9][10][11] and in experiments [12][13][14][15]. Moreover, a degenerate oscillatory state and a state with large particles asymmetrically distributed and small particles equally distributed has been found in 3D molecular dynamics simulation recently [9].…”

“…Special attentions are given to compartmentalized systems (as shown in Fig. 1a) in which many interesting clustering phenomena are observed [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. A spontaneous symmetry-breaking phenomenon called "Maxwell demon" was first observed in a mono-disperse granular gas experimentally by Schlichting et al [5] and in simulation by Schinner [6].…”

“…Miao et al [13] extended the mono-disperse flux model to a bi-disperse flux model by adding a simple coupling term between the two species. Lambiotte et al [11] and Viridi et al [14] proposed a simple phenomenological model by taking the vertical segregation (the Brazil nut effect or the reverse Brazil nut effect) into consideration. In our previous paper we proposed an empirical function having temperatures specific to the two types of particles and also dependent on the composition of granular gas [12].…”

Experimental study of granular convection in (real) two- dimension Brazil-nut effect

“…It is including intruder, bed particles, and also the container box. The use of the same materials for all components will prevent the occurrence of unpredictable and annoying electrostatic charging [11]. Diameter of bed particle is 0.55 cm.…”