Particle Trajectories and Segregation in a Two-Dimensional Rotating Drum.

The size segregation phenomenon of granular materials in a two-dimensional rotating drum is simulated very efficiently using a simplified deterministic model. We demonstrate ergodicity in the sense that the statistical properties of a particle trajectory reflect the behaviour of the whole assembly. Segregation is shown to occur in a bidisperse system even if the radii of the particles are very similar (ratio as big as 0.9).