STRUCTURAL FEATURES IN GRANULAR FLOWS

High-speed motion pictures document a series of essentially two-dimensional, free-surface flows of a 6-mm diameter plastic spheres generated in an inclined glass-walled chute 3.7 m long and 6.7 mm wide. Flows exhibit a diverse suite of structural features, depending on particle flux, chute inclination, and geometry of the fixed bed. Flows at sufficiently low inclination or high particle flux can generally be divided into frictional and collisional regions. -from Author