Wet granular flow control through liquid induced cohesion

Liquid induced cohesion has a significant effect on the flow characteristics of wet granular assemblies. The strength of capillary forces between the particles can be continuously tuned by making the glass beads hydrophobic via chemical silanization. Main results of rotating drum experiments are that stronger liquid-induced cohesion decreases the width of the flowing region, the velocity of the particles at the free surface and the local granular temperature, but in contrast, increases the width of the creeping region as well as the dynamic angle of repose. Our proposed scaling methodology yields invariant bed flow characteristics for different particle sizes in the flow regimes considered (rolling and cascading regimes), and thus allows to control the flow. • Glass beads are silanized to change their surface properties • Wet granular flow is investigated in a rotating drum • Capillary forces increase the dynamic angle of repose • The scaling approach yields similar flow characteristics.