Granular Flow in Hoppers and Tubes: Gas Grain Interaction

摘要

We have studied the effect of gas-grain interaction on the flow of sand for two different experiments. The first experiment deals with the intermittent flow observed in a closed hour-glass. The intermittency results from a coupling between the flow of sand and convection of air through the sand. The second experiment deals with the oscillatory flow observed in an open silo. In this case a local mechanism is caused by dilation of the granular material and interaction with the interstitial air is responsible for the observed oscillations.