Surface flows, segregation and surface instabilities in silo flows
Flow and segregation in silo flows
We study the flow of granular material draining through an orifice in a two-dimensional glass silo using high-resolution imaging. Two phases are observed: a static solid-like region, and a rapidly flowing fluid-like region. Size segregation is observed when multi-sized particles are used, with larger particles found in the center of the silo, where the flow is the fastest. We have quantitatively investigated the development of segregation as a function of time and as a function of size ratio of the particles and the flow rate.
Granular Hydraulic Jump
The width of the viewing region is 3 inches and the orifice is 1 inch wide. The surface is observed to deviate strongly from the approximately linear profile observed at low flow rates. Watch a movie of a surface instability observed at high discharge rates.