STEADY PARTICULATE FLOWS IN A HORIZONTAL ROTATING CYLINDER

Results of discrete element method (DEM) simulation and magnetic reson ance imaging (MRT) experiments are compared for monodisperse granular materials flowing in a half-filled horizontal rotating cylinder. Becau se opacity is not a problem for MRI, a long cylinder with an aspect ra tio similar to 7 was used and the flow in a thin transverse slice near the center was studied. The particles were mustard seeds and the rati o of cylinder diameter to particle diameter was approximately 50. The parameters compared were dynamic angle of repose, velocity held in a p lane perpendicular to the cylinder axis, and velocity fluctuations at rotation rates up to 30 rpm. The agreement between DEM and MRI was goo d when the friction coefficient and nonsphericity were adjusted in the simulation for the best fit. (C) 1998 American Institute of Physics.