Hill K M, Gioia G, Amaravadi D
Department of Theoretical and Applied Mechanics, University of Illinois, Urbana, Illinois 61801, USA.
Phys Rev Lett. 2004 Nov 26;93(22):224301. doi: 10.1103/PhysRevLett.93.224301. Epub 2004 Nov 22.
We model the radial segregation patterns that form in a thin rotating drum partially filled with beads of two sizes. We predict that the waviness (or amplitude-to-wavelength ratio, denoted w) of a pattern should be subjected to low-pass filtering with a cutoff waviness w(c) that depends strongly on the fill level of the drum. Then we perform experiments and find that w</=w(c) for all patterns, in accord with our prediction. We also find that w=w(c) for (and only for) steady patterns, and conclude that the waviness of a steady pattern is selected by the low-pass filtering.
我们对在部分填充有两种尺寸珠子的薄旋转鼓中形成的径向分离模式进行建模。我们预测，一种模式的波纹度（或振幅与波长之比，记为w）应通过截止波纹度为w(c)的低通滤波进行处理，w(c)在很大程度上取决于鼓的填充水平。然后我们进行实验，发现所有模式的w≤w(c)，这与我们的预测一致。我们还发现，对于稳定模式（且仅对于稳定模式）有w = w(c)，并得出结论：稳定模式的波纹度是通过低通滤波选择的。
