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Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
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Friction controls even submerged granular flows.
Juha Koivisto1, Marko Korhonen, Mikko Alava
1Department of Applied Physics, Aalto University, Aalto 00067, Finland. juha.koivisto@aalto.fi.
Soft Matter
|October 10, 2017
Summary
Flow rate in submerged hoppers surges due to fluid-particle coupling, unlike constant dry flow. This study models granular flow, revealing friction changes underwater.
Area of Science:
- Physics
- Engineering
- Fluid Dynamics
Background:
- Granular materials exhibit complex flow behaviors.
- Understanding fluid-particle interactions is crucial for industrial processes.
Purpose of the Study:
- To investigate the coupling between interstitial fluid and granular particles in hopper flow.
- To compare the flow dynamics of dry and submerged granular systems.
- To model and validate experimental observations using numerical simulations.
Main Methods:
- Experimental study of dry and submerged hopper flow.
- Numerical modeling using the discrete element method (DEM).
- Coupling DEM with computational fluid dynamics (CFD) for submerged systems.
Main Results:
- Dry hopper flow exhibits a constant discharge rate.
- Submerged hopper flow demonstrates a surging flow rate.
- Numerical models accurately replicate experimental data upon fitting friction parameters.
Conclusions:
- Fluid-particle coupling significantly alters granular flow dynamics in submerged systems.
- Particle-particle contact friction is reduced when submerged (0.15 to 0.13).
- Accurate modeling requires system-specific parameter calibration.
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