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Updated: Mar 24, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
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Declustering in a granular gas as a finite-size effect
Mathias Hummel1, Marco G Mazza1
1Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Fassberg 17, 37077 Göttingen, Germany.
Physical Review. E
|March 18, 2016
Summary
Dense granular clusters form temporarily in simulations where particle collisions depend on impact speed. These structures dissolve over time, with larger systems taking longer to decluster, following a specific power law.
Area of Science:
- Physics
- Granular Mechanics
- Computational Physics
Background:
- Realistic granular collision models show dense cluster formation is transient.
- The coefficient of restitution in granular systems often depends on impact velocity.
Purpose of the Study:
- To elucidate conditions for the disappearance of granular structures.
- To investigate the relationship between granular temperature, convective kinetic energy, and system size.
Main Methods:
- Direct numerical simulations of granular collisions.
- Analysis of cluster formation and dissolution dynamics.
- Investigation of Haff's law in simulated granular systems.
Main Results:
- Granular temperature and convective kinetic energy couple upon cluster formation, following Haff's law.
- Granular clusters dissolve in all finite-size systems.
- Declustering time exhibits a strong power-law dependence on system size (t'∝L^12).
Conclusions:
- Granular clusters are inherently transient phenomena in finite systems.
- The system size critically influences the timescale of both clustering and declustering.
- Observable clustering and declustering transitions require systems near a critical initial size.
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