Berlin 2012 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 21: Granular Matter/Contact Dynamics
DY 21.1: Talk
Wednesday, March 28, 2012, 14:30–14:45, MA 144
Coefficient of restitution for wet impacts — Frank Gollwitzer1, Christof Kruelle2, Ingo Rehberg1, and •Kai Huang1 — 1Experimentalphysik V, Universitaet Bayreuth, 95440 Bayreuth, Germany — 2Maschinenbau und Mechatronik, Hochschule Karlsruhe - Technik und Wirtschaft, D-76133 Karlsruhe, Germany
As the experience of playing football in the rain may tell, wetting could influence the coefficient of restitution (COR) dramatically. This is due to the extra energy dissipation from the wetting liquid, for instance viscous damping. To unveil the underlying mechanisms accounting for the influence, we study experimentally the COR by tracing free falling particles bouncing on a wet surface. The dependance of the COR on the impact velocity, various particle and liquid properties will be presented and discussed in terms of dimensionless numbers that characterize the interplay between inertia, viscous and surface forces.