Berlin 2015 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 4: Granular Matter / Contact Dynamics Part I

DY 4.7: Vortrag

Montag, 16. März 2015, 11:15–11:30, BH-N 128

Cooling of 3D Granular Gases: Microgravity Experiments — •Kirsten Harth, Torsten Trittel, Sandra Wegner, Kathrin May, and Ralf Stannarius — Institut für Experimentelle Physik, Otto von Guericke Universität Magdeburg

Granular gases represent one of the simplest systems for investigations of non-equilibrium statistical physics, yet they are still poorly understood. They represent ensembles of macroscopic grains interacting through inelastic collisions. The use of elongated grains facilitates the realization of 3D experiments beyond the Knudsen regime. We recently found non-gaussian velocity distributions and a violation of the equipartition of kinetic energy, i.e. rotational degrees of freedom are underexcited [1]. With a special preparation technique, we can study such systems during the short microgravity period offered by drop towers. We present the first experimental study based on 3D data, with focus on the initial period of granular cooling. Experiments were conducted at the ZARM drop tower in Bremen, with approx. 9.2 of microgravity. We analyze and compare velocity and density distributions as well as the decay of kinetic energy in different experimental realizations.

[1] K. Harth, U. Kornek, T. Trittel, U. Strachauer, S. Höme, K. Will, R. Stannarius, Phys. Rev. Lett. 110 144102 (2013)