Friction-mediated flow and jamming in a two-dimensional silo with two exit orifices

Area of Science:

• Physics of granular materials
• Fluid dynamics
• Statistical mechanics

Background:

• Granular materials exhibit complex flow and jamming behaviors, particularly in confined geometries like silos.
• The interplay between interparticle forces and external factors, such as orifice configuration, is crucial for understanding material flow dynamics.

Purpose of the Study:

• To investigate the influence of interparticle friction coefficient on the flow and jamming behavior of granular materials exiting a two-dimensional silo.
• To analyze the effect of a nearby orifice on the flow dynamics and intermittency of granular discharge.

Main Methods:

• Experimental setup involving a two-dimensional silo with two orifices.
• Systematic variation of the interparticle friction coefficient and inter-orifice distance.
• Analysis of flow intermittency, jamming/flowing event durations, and unjamming frequencies.

Main Results:

• Interparticle friction significantly alters granular flow and jamming. Higher friction increases mean jamming duration and decreases mean flow duration.
• Unjamming frequency exhibits non-monotonic behavior with increasing friction, indicating transitions between jammed and flowing states.
• Inter-orifice distance modulates fluctuation strength, impacting unjamming events; jamming and flowing time distributions show exponential and power-law tails, respectively.

Conclusions:

• Interparticle friction is a key parameter governing the transition between intermittent and continuous flow in granular silos.
• The presence and proximity of multiple orifices create complex dynamics, leading to predictable jamming and flowing behaviors influenced by friction and geometry.