Inertia in the Brazil nut problem

Abstract

The rise dynamics of a large particle, in a granular bed under vertical vibrations, is experimentally studied with an inductive device designed to track the particle while it climbs through the granulate under different conditions. A model based on energy considerations is presented to explain our experimental data, drawing the important conclusion that it is the inertia of the particle, assisted by Reynolds dilatancy, the driven force behind its ascension mechanism. The ascension reveals a friction profile within the column which remains unchanged for different accelerations.

A Horizontal Brazil-Nut Effect and Its Reverse

“…This puzzling phenomenon has become known as ''reverse Brazil-nut effect.'' Recent theoretical and experimental studies [13][14][15][16][17][18][19] have investigated under which conditions both effects, the rise or descent of the larger particles, may occur.…”

Convection Rolls and Individual Particles Movements in Horizontally Vibrated Granular Particles System

“…Behaviors of granular material are excessively difficult to understand because Newtonian mechanics and fluid dynamics cannot employ directly. The Brazilian nut effect (BNE) is one such system that has been studied much experimentally [1][2][3][4][5] and theoretically [6][7][8][9]. Similar behaviors detected on horizontal swirling motion in circular plates [10] large bead will migrate either to the center or to the border of the plate.…”

“…When the position of heap was at center then large particles moved toward the walls perpendicular to direction of vibration and toward the corners of container. Gaps were observed between walls perpendicular to direction of vibration and particles due to collisions of particles and walls (1,2). Gap spread greater as increase in dimensionless acceleration Γ , and these gaps filled by the large particle coming from the center of container as shown in Fig.…”

Mutiscale Modeling of Segregation in Granular Flows

“…We compare the rising time to a related experimental system (Nahmad-Molinari et al, 2003) and show that the rising of the large particle is very sensitive to wall friction. Furthermore, we show the existence of large-scale force networks when wall friction is present and relate the rise dynamics to formation and destruction of these force networks.…”