Title: What will happen if you rotate sand in a tilted spinning bucket?
Speaker: Professor I. Yu
Speaker Info: Seoul National University
A few years ago we discovered a circular step-like kink pattern formation on the granular surface of sand rotating in a tilted spinning beaker. The radius of the kink is proportional to the inverse square of the spinning speed, R_kink proportional to omega^-2, and dependent on the tilting angle. We explained the phenomenon by studying the force balance condition with the usual Coulomb criteria of friction for the sand grains at the kink. We are also studying the slow relaxational time behavior of packing for a model granular system (randomly packed steel bearings). I will describe what we found as well as what we plan to do in near future.Date: Friday, February 11, 2000