A variety of flow regimes can be observed within the silo itself according to the geometry
and solid properties (Fig. 1). In case of silo flow can be distinguish two main types of
flow [2, 4, 8, 11, 13]. The basic two types of flow behaviour are ‘mass flow’ and ‘core’ (or
‘funnel’) flow. Mass flow is characterized by all the material discharging uniformly with the
same downward velocity across the entire cross section area, hence at a constant mass discharge
rate. In contrast in ‘funnel’ or ‘core’ flow, as the name suggests, material is flowing