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Updated: Jun 21, 2026
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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Expanding holes driven by convectionlike flow in vibrated dense suspensions
1Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan. ebata@daisy.phys.s.u-tokyo.ac.jp
Summary
Vertically vibrated suspensions show surface instabilities above a critical acceleration. These instabilities, including holes and segregation, are linked to convection-like flow, with its height scalable by key physical parameters.
Area of Science:
- Fluid dynamics
- Materials science
- Non-Newtonian fluids
Background:
- Surface instabilities in vibrated granular materials are crucial for understanding complex fluid behaviors.
- Previous studies often focused on 2D systems, leaving 1D dynamics less explored.
Purpose of the Study:
- Investigate surface instabilities in vertically vibrated suspensions in quasi-1D and quasi-2D systems.
- Characterize the resulting patterns and associated fluid flow.
- Develop a model to explain the observed scaling laws.
Main Methods:
- Experimental investigation of powder-silicone oil suspensions under vertical vibration.
- Utilized quasi-1D and quasi-2D confined geometries.
- Analyzed surface patterns and measured convection-like flow dynamics.
Main Results:
- Above a critical acceleration, flat suspension surfaces became unstable.
- Quasi-2D systems exhibited expanding holes or viscous fingering.
- Quasi-1D systems showed segregation into dry and wet regions.
- Instabilities were accompanied by convection-like flow at their rims.
- Convection-like flow height in 1D systems scaled with acceleration, frequency, particle size, density, and viscosity.
Conclusions:
- Vertical vibration induces distinct surface instabilities in confined suspensions.
- Convection-like flow plays a key role in these instabilities.
- A proposed model successfully explains the scaling and motion of the observed flow patterns.
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