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Updated: Nov 9, 2025

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Particle Dynamics at the Onset of the Granular Gas-Liquid Transition
M Noirhomme1, A Cazaubiel2, E Falcon2
1GRASP, CESAM Research Unit, Institut de Physique B5a, Sart Tilman, University of Liège, B-4000 Liège, Belgium.
Abstract:
We study experimentally the dynamical behavior of few large tracer particles placed in a quasi-2D granular "gas" made of many small beads in a low-gravity environment. Multiple inelastic collisions transfer momentum from the uniaxially driven gas to the tracers whose velocity distributions are studied through particle tracking. Analyzing these distributions for an increasing system density reveals that translational energy equipartition is reached at the onset of the gas-liquid granular transition corresponding to the emergence of local clusters. The dynamics of a few tracer particles thus appears as a simple and accurate tool to detect this transition. A model is proposed for describing accurately the formation of local heterogeneities.
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