Otto-von-Guericke Universität Magdeburg, Institute for Experimental Physics, D-39016 Magdeburg, Germany.
Institute of Physics, Budapest University of Technology and Economics, H-1111 Budapest, Hungary.
Phys Rev E. 2016 Mar;93(3):032903. doi: 10.1103/PhysRevE.93.032903. Epub 2016 Mar 8.
Segregation of polydisperse granular materials in rotating containers is a ubiquitous but still not satisfactorily understood phenomenon. This study describes axial segregation of bidisperse granular mixtures of glass beads in a spherical container, rotating about its horizontal axis. Depending on the filling fraction of the mixer and on the composition of the mixture, qualitatively different spontaneously formed patterns are observed. For technical applications, the well-localized segregated bands allow a convenient separation of individual components of the mixtures. It is particularly surprising that the initial compositions of the granular mixtures have a fundamental influence on the location of the segregated bands. This evidences a collective pattern forming mechanism. The spontaneous formation of these bands cannot simply be traced back to individual particle dynamics. Existing models for segregation in spherical mixers are critically examined and extensions are suggested.
多分散颗粒材料在旋转容器中的分离是一种普遍存在但仍未得到满意解释的现象。本研究描述了球形容器中玻璃珠双分散颗粒混合物的轴向分离，容器绕水平轴旋转。根据混合器的填充分数和混合物的组成，可以观察到定性上不同的自发形成的模式。对于技术应用，这些良好定位的分离带允许方便地分离混合物的各个成分。特别令人惊讶的是，颗粒混合物的初始组成对分离带的位置有根本影响。这证明了一种集体模式形成机制。这些带的自发形成不能简单地追溯到单个颗粒的动力学。对现有的球形混合器中分离的模型进行了批判性的检查，并提出了扩展。
