Berlin 2018 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 83: Pattern Formation II

DY 83.3: Talk

Friday, March 16, 2018, 10:30–10:45, BH-N 333

Front propagation in agitated wet granular matter — Andreas Zippelius and •Kai Huang — Experimentalphysik V, University of Bayreuth, 95440 Bayreuth, Germany

Abstract: From sand dunes to Faraday heaping, granular materials (i.e. large agglomeration of macroscopic particles) are rich pattern forming systems. When the particles are partially wet (e.g. wet sand on the beach), a different pattern forming scenario arises due to cohesion: Kink-wave fronts were found to be the dominating pattern [1]. Here, we focus on the formation of density-wave fronts in an oscillated wet granular layer undergoing a gas-liquid-like transition [2]. The threshold of the instability is governed by the amplitude of the vertical vibrations. Fronts, which are curved into a spiral shape, propagate coherently along the circular rim of the container with leading edges. They are stable beyond a critical distance from the container center. Based on the measurement of the critical distance and the rotation frequency, we propose a model for the pattern formation by considering the competition between the time scale for the collapse of cohesive particles and that of the energy injection resisting this process. 0.5em [1] Butzhammer, L., Völkel, S., Rehberg, I. & Huang, K. Phys. Rev. E 92, 012202 (2015).
[2] Zippelius, A. & Huang, K. Sci. Rep. 7, 3613 (2017)