Poschel T, Schwager T, Saluena C
ICA 1, Universitat Stuttgart, Pfaffenwaldring 27, D-70569 Stuttgart, Germany and Institut fur Physik, Humboldt-Universitat zu Berlin, Invalidenstrasse 110, D-10115 Berlin, Germany.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Jul;62(1 Pt B):1361-7. doi: 10.1103/physreve.62.1361.
When granular material is shaken vertically one observes convection, surface fluidization, spontaneous heap formation, and other effects. There is a controversial discussion in the literature as to whether there exists a threshold for the Froude number Gamma=A(0)omega(2)(0)/g, below which these effects cannot be observed anymore. By means of theoretical analysis and computer simulation we find that there is no such single threshold. Instead, we propose a modified criterion that coincides with the critical Froude number Gamma(c)=1 for small driving frequency omega(0).
当颗粒材料垂直振动时，人们会观察到对流、表面流化、自发堆形成以及其他效应。关于弗劳德数Gamma = A(0)omega(2)(0)/g是否存在一个阈值，低于该阈值这些效应就不再能被观察到，文献中存在有争议的讨论。通过理论分析和计算机模拟，我们发现不存在这样一个单一的阈值。相反，我们提出了一个修正准则，对于小驱动频率omega(0)，该准则与临界弗劳德数Gamma(c)=1一致。
