Outflow and clogging of shape-anisotropic grains in hoppers with small apertures

摘要: Outflow of granular material through a small orifice is fundamental process in many industrial fields, for example silo discharge, and everyday's life. Most experimental studies the dynamics have been performed so far with monodisperse disks two-dimensional (2D) hoppers or spherical grains 3D. We investigate this shape-anisotropic 3D discuss role size shape parameters on avalanche statistics, clogging states, mean flow velocities. It shown that an increasing aspect ratio leads to lower rates higher probabilities compared grains. On other hand, number forming clog larger elongated comparable volumes, long axis these blocking preferentially aligned towards center orifice. find qualitative transition hopper discharge behavior ratios than ≈6. At still >8–12, outflowing leaves vertical holes penetrate complete bed. This changes characteristics qualitatively.