Scherer MA, Kotter K, Markus M, Goles E, Rehberg I
Institut fur Experimentelle Physik, Otto-von-Guericke-Universitat, Postfach 4120, D-39016 Magdeburg, Germany.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Apr;61(4 Pt B):4069-77. doi: 10.1103/physreve.61.4069.
Experiments and three-dimensional numerical simulations are presented to elucidate the dynamics of granular material in a cylindrical dish driven by a horizontal, periodic motion. The following phenomena are obtained both in the experiments and in the simulations: First, for large particle numbers N the particles describe hypocycloidal trajectories. In this state the particles are embedded in a solidlike cluster ("pancake") which counter-rotates with respect to the external driving (reptation). Self-organization within the cluster occurs such that the probability distribution of the particles consists of concentric rings. Second, the system undergoes phase transitions. These can be identified by changes of the quantity dE(kin)/dN (E(kin) is the mean kinetic energy) between zero (rotation), positive (reptation), and negative values (appearance of the totality of concentric rings).
本文通过实验和三维数值模拟，阐明了在水平周期性运动驱动下圆柱形容器内颗粒材料的动力学特性。实验和模拟均得到了以下现象：首先，对于大量粒子数N，粒子描绘出内摆线轨迹。在此状态下，粒子嵌入类似固体的团簇（“薄饼”）中，该团簇相对于外部驱动反向旋转（蠕动）。团簇内部发生自组织，使得粒子的概率分布由同心环组成。其次，系统经历相变。这些相变可通过量dE(kin)/dN（E(kin)为平均动能）在零（旋转）、正值（蠕动）和负值（同心环整体出现）之间的变化来识别。
