Discharge of non-spherical particles from a monolayer silo

We performed well-controlled experiments comparing the outflow of monodisperse batches of spheres and of several non-spherical particles from a quasi-two-dimensional monolayer silo. We investigate the velocity and solid fraction profiles at the orifice and test whether the profiles for the non-spherical particles have similar self-similar properties as in the spherical case. We find that the magnitude and shape of the velocity profiles for all particle types are in the same range. In contrast, the solid fraction at the orifice has a dome-shaped profile for the non-spherical particles, whereas the profile for the spherical case is rather flat. The discharge rate determined from the velocity and solid fraction profiles describes the independently measured experimental discharge rate very well for all investigated particle types.