Granular chute flow

This is a simulation of granular flow down an inclined chute. Because of the rough base, the lower region of the material flows more slowly than the upper, and the resulting shear causes the larger grains to rise to the surface. This effect can be observed here (for convenience the inclined chute is drawn horizontally, so the direction of gravity is not vertical). The underlying model consists of rough, rotating disklike particles, with a narrow range of sizes, whose collisions are inelastic, together with a single large disk. The side walls are actually periodic boundaries.

Available user controls are buttons to start/stop and reset the simulation, and sliders for regulating the relative size of the large disk, the strength of the gravitational field, the slope angle, and the number of timesteps between display updates.