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Coarsening of Faraday heaps: experiment, simulation, and theory
Henk Jan van Gerner1, Gabriel A Caballero-Robledo, Devaraj van der Meer
1Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands.
Physical Review Letters
|August 8, 2009
Summary
Faraday heaps in shaken granular materials form and merge over time. Their lifespan scales with heap number, and their quantity decreases over time, as described by a new differential equation model.
Area of Science:
- Physics
- Complex Systems
- Granular Dynamics
Background:
- Vertically shaken granular materials exhibit complex surface dynamics.
- Faraday heaps, transient structures, emerge and coarsen over time.
Purpose of the Study:
- To investigate the coarsening process of Faraday heaps in a linear setup.
- To develop a model describing the evolution and lifespan of these structures.
Main Methods:
- Experimental study of granular material under vertical shaking.
- Development of a differential equation model for peak positions.
- Comparison of model predictions with experimental and simulation data.
Main Results:
- The average lifespan of N Faraday heaps scales as N^-3.
- A model accurately predicts the evolution of the granular landscape.
- The number of heaps decreases over time as N(t) ∝ t^-1/2.
Conclusions:
- A novel differential equation model effectively describes Faraday heap coarsening.
- The model provides quantitative agreement with experimental and simulation results.
- The study elucidates the dynamics of pattern formation and coarsening in granular systems.
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