Yuan Xiaoxian, Zheng Ning, Shi Qingfan, Sun Gang, Li Liangsheng
School of Physics, Beijing Institute of Technology, Beijing 100081, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Apr;87(4):042203. doi: 10.1103/PhysRevE.87.042203. Epub 2013 Apr 10.
We experimentally investigate segregation behaviors of binary granular mixtures consisting of granular chains and spherical grains with different interstitial media under vertical vibrations. A quantitative criterion is proposed to locate the boundaries between different vibrating phases. The water-immersed granular mixture exhibits two interesting types of segregation behaviors: chain-on-top and sandwich patterns. However, the phenomenon of sandwich segregation is absent for the air-immersed mixture. The topological differences of phase diagrams between two different environments indicate that the interstitial fluid plays an important role on the granular demixing. Additionally, the phase behaviors of mixtures for the different chain lengths show a not significant discrepancy. Finally, the vibrating thickness ratio determining the phase boundary characterizes the mixing extent of the granular bed. The estimated ratios for various chain lengths exhibit a monotonically decreasing dependence, when the vibration frequency increases.
我们通过实验研究了在垂直振动下，由颗粒链和球形颗粒组成的二元颗粒混合物在不同间隙介质中的分离行为。提出了一种定量标准来确定不同振动相之间的边界。水浸颗粒混合物表现出两种有趣的分离行为类型：链在上和三明治模式。然而，气浸混合物中不存在三明治分离现象。两种不同环境下相图的拓扑差异表明，间隙流体在颗粒分离中起着重要作用。此外，不同链长混合物的相行为差异不显著。最后，决定相边界的振动厚度比表征了颗粒床的混合程度。当振动频率增加时，各种链长的估计比值呈现单调下降的依赖性。
