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DY: Fachverband Dynamik und Statistische Physik

DY 18: Granular Matter / Contact Dynamics

DY 18.1: Vortrag

Mittwoch, 2. April 2014, 09:30–09:45, ZEU 118

Onset of wall induced convection in vertically oscillated granular systems — •Andrea Fortini — Theoretische Physik II, Physikalisches Institut, Universität Bayreuth, Universitätsstraße 30, D-95447 Bayreuth, Germany

We investigate with two-dimensional computer simulations the onset of the wall-induced convection in vertically shaken granular matter. The convection is one of the major contributing mechanism responsible for the brazil nut effect, i.e. the rise of big particles in a container of small grains. We investigate the convective motion in relation to the dynamical phase diagram of monodispersed grains and show that the wall-induced convection occurs inside the "bouncing bed" region of the parameter space in which the granular bed behaves like a bouncing ball. We find that the onset of the convective motion is caused by the activation of slip mechanisms of the crystalline planes in the closed-packed granular bed. Furthermore, we explore the role of defects and grain boundaries in the onset of convection.