Final average residual saturation of granular beds under air blow drainage.

Collapsing granular beds: the role of interstitial air.

A prefluidized sand bed consisting of fine particles compactifies when it is subjected to a shock. We observe that the response depends on both the shock strength and the ambient pressure, where, counterintuitively, at high ambient pressure the compaction is larger, which we connect to a decrease of the static friction inside the bed. We find that the interstitial air is trapped inside the bed ...

Interaction between intruders in vibrated granular beds.

Two neutrally buoyant intruder particles in a granular bed fluidized by vertical, sinusoidal vibration are known to interact with each other over a range of about five intruder diameters. Using molecular dynamics simulations, we investigate in detail the spatial and temporal nature of this interaction. We show that the force of attraction between intruders can be calculated from the local densi...

Granular Pressure Measurement in Fluidized Beds

Experiments were carried out to measure the additional pressure, called the granular pressure, which is exerted on the containing wail of a fluidized bed due to particle collisions with that wall. Measurements were made for water fluidized beds using glass beads of 1.3 mm and 3 mm diameter, lead shot of 2.1 mm diameter and plastic particles. The granular pressure was observed to increase to a m...

Intruder clustering in three-dimensional granular beds.

We present results of computer simulations for neutrally buoyant intruders in a vertically vibrated three-dimensional granular bed of smaller host particles. Under sinusoidal excitation, pairs of intruders interact over a distance of several intruder diameters; a group of intruders forms a cluster. The strength of the interaction grows as the number of intruders is increased. We show that the t...

Convection in three-dimensional vibrofluidized granular beds