Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 19: SYMPOSIUM Driven Soft Matter IV
CPP 19.8: Vortrag
Mittwoch, 27. Februar 2008, 15:45–16:00, C 130
Correlations in granular media with volume driving — •Wolf Till Kranz1, Timo Aspelmeier1, and Annette Zippelius1,2 — 1Max-Planck-Institut für Dynamik und Selbstorganisation, Göttingen — 2Universität Göttingen
Due to the dissipative nature of the interaction of granular particles an input of energy is needed in order to reach a stationary state. The simplest example of energy injection, volume driving by randomly forcing each particle, leads to an unphysical divergence of the structure factors at long wavelengths. We show that this divergence is removed when the driving is modified to obey momentum conservation. The length scale l on which momentum is conserved determines the length scale on which correlations build up: on lengths scales shorter than l the remnants of the divergence are still visible while it is suppressed on longer scales. We discuss the long wavelength behaviour of the static structure factor and the longitudinal current correlation function.