M. A. Aguirre

Pressure independence of granular flow through an aperture.

We experimentally demonstrate that the flow rate of granular material through an aperture is controlled by the exit velocity imposed on the particles and not by the pressure at the base, contrary to what is often assumed in previous work. This result is achieved by studying the discharge process of a dense packing of monosized disks through an orifice. The flow is driven by a conveyor belt. This two-dimensional horizontal setup allows us to independently control the velocity at which the disks escape the horizontal silo and the pressure in the vicinity of the aperture. The flow rate is found to be proportional to the belt velocity, independent of the amount of disks in the container and, thus, independent of the pressure in the outlet region. In addition, this specific configuration makes it possible to get information on the system dynamics from a single image of the disks that rest on the conveyor belt after the discharge.

ENERGY DISSIPATION AND TRAPPING OF PARTICLES MOVING ON A ROUGH SURFACE

We report on an experimental, numerical, and theoretical study of the motion of a ball on a rough inclined surface. The control parameters are

Effects of geometry on the characteristics of the motion of a particle rolling down a rough surface

D

Granular packing: influence of different parameters on its stability

, the diameter of the ball,

Surface fluctuations in a slowly driven granular system

\ensuremath{\theta}

Experimental acoustic technique in granular flows

, the inclination angle of the rough surface, and

Avalanche Parameters: Dependence on the Size of the Granular Packing

{E}_{\mathrm{ki}},

Arch size distribution in a two‐dimensional pile of disks

the initial kinetic energy. When the angle of inclination is larger than some critical value,

Instabilities in slowly driven granular packing

\ensuremath{\theta}g{\ensuremath{\theta}}_{T},

Influence of the number of layers on the equilibrium of a granular packing

the ball moves at a constant average velocity, which is independent of the initial conditions. For an angle