Statistical properties of gravity-driven granular discharge flow under the influence of an obstacle

Abstract

Two-dimensional granular discharge flow driven by gravity under the influence of an obstacle is experimentally investigated. A horizontal exit of width $W$ is opened at the bottom of vertical Hele-Shaw cell filled with stainless-steel particles to start the discharge flow. In this experiment, a circular obstacle is placed in front of the exit. Thus, the distance between the exit and obstacle $L$ is also an important parameter. During the discharge, granular-flow state is acquired by a high-speed camera. The bulk discharge-flow rate is also measured by load cell sensors. The obtained high-speed-image data are analyzed to clarify the particle-level granular-flow dynamics. Using the measured data, we find that the obstacle above the exit affects the granular-flow field. Specifically, the existence of obstacle results in large horizontal granular temperature and small packing fraction. This tendency becomes significant when $L$ is smaller than approximately 6$D_g$ when $W\simeq 4D_g$, where $D_g$ is diameter of particles.

4 pages, 5 figures

References in corpus (6)

• Introduction of Frictional and Turning Function for Pedestrian Outflow with an Obstacle
• Fraction of clogging configurations sampled by granular hopper flow
• Diffusion and mixing in gravity-driven dense granular flows
• Invited review: Clogging of granular materials in bottlenecks
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Cited by in corpus (5)

• Obstacle-shape effect in a two-dimensional granular silo flow field
• Shape dependence of resistance force exerted on an obstacle placed in a gravity-driven granular silo flow
• The effect of obstacles near a silo outlet on the discharge of soft spheres
• Enhanced flow rate by the concentration mechanism of Tetris particles when discharged from a hopper with an obstacle
• Understanding the Local Flow Rate Peak of a Hopper Discharging Discs through an Obstacle Using a Tetris-like Model