Hysteresis in granular media subjected to axisymmetrical rotation

In this work we have studied the hysteretic behavior for the mean slope of the free surface of noncohesive granular media under axisymmetrical rotatio n. In order to study the hysteresis loop the relationship between the avera ge slope of the free surface (most important measurable quantity) and the F roude number has been established. Differences between experiments and theo retical predictions are also shown. Theory predicts that hysteresis must di sappear as the friction coefficient mu Of the granular material reaches uni ty. However, this condition could not be reached experimentally using tapio ca (where mu similar to 1 ), due to the important difference between the an gle of internal friction and the angle of repose for small containers.