Segregation patterns in V-blenders

We report several segregation patterns in V-blenders partially filled with mixtures of glass beads differing in size. Three dominant patterns are found, including one in which larger and smaller particles migrate to opposite halves of the blender. Changes in the rotation rate by as little as 3% can cause a change of pattern. Analysis of particle pathlines suggests that segregation in this vessel may be dominated by 'trajectory segregation', i.e. the inability of larger, more inertial, particles to navigate sharp bends in pathlines.