Phase Transitions and Segregation Phenomena in Vibrated Granular Systems

Abstract

A summary of results is presented from experiments in granular systems, which are excited by vertical and/or horizontal vibrations. The transitions between different dynamic states depend on internal properties of the granular system like the density of particles as well as external parameters of the driving shakers. Characteristic for granular systems are counterintuitive phenomena like the crystallization by increasing the vibration amplitude and thereby the energy input, or the rise of large particles in a sea of smaller ones (Brazil-nut effect). For horizontal shaking of a binary system the demixing of small and large particles is found to occur at the same critical particle density as the liquid-solid transition, which leads to the conclusion that both phenomena, segregation and phase transition, are closely related.