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Updated: Jul 11, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Granular fingers on jammed systems: new fluidlike patterns arising in grain-grain invasion experiments
S F Pinto1, M S Couto, A P F Atman
1Departamento de Física, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil.
Abstract:
In this Letter we report spontaneous pattern formation in dense granular assemblies confined to a Hele-Shaw cell and quasistatic regime. Varied unexpected patterns, ranging from rounded to fingered, are observed due to the displacement of one granular material by another. Computer simulations reproduce the major features observed in these experiments. Two mechanisms are responsible for the pattern formation: crystallization of the injected grains and plastic deformation of the displaced grains. The experiment suggests analogies with viscous fingering and jamming transition experiments.
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