The dynamics of fine powders in a rotating drum

Granular materials exhibit several regimes of behavior: plastic, inertial, fluidized, and entrained how but not all materials can pass through all the se states. Our concern is with the criteria that determine the transition f rom one regime to another and with the boundaries to the various flow regim es that these criteria define. We have focused on fine, cohesive powders, w here the interparticle cohesive force dominates over the gravitational forc e. The experiments to analyze this topic have been performed using a rotati ng drum device.