Rheology and Segregation in Dense Sheared Granular Flows

Particles in motion tend to segregate by particle properties such as
size, density and shape. When particle-scale segregation mechanisms
(e.g., gravity and shear rate gradients) combine with system-wide
advection they give rise to a wide variety of large scale segregation
patterns. In and of itself, segregation phenomenology can be
fascinating. Additionally, the presence of segregation patterns can
significantly influence flow behaviors in granular materials as the
local and global rheologies vary with the local and global
concentrations. Understanding these phenomena is important for a wide
range of granular flows that help shape the earth surface including
rocky debris flows and sediment transport in rivers. This presentation
will describe small-scale experiments and simulations we use to
develop models for the interdependence between segregation and
rheology in relatively simple sheared granular flows.