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Updated: May 13, 2026
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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
Shallow granular flows down flat frictional channels: steady flows and longitudinal vortices
Nicolas Brodu1, Patrick Richard, Renaud Delannay
1Institut Physique de Rennes, UMR CNRS 6251, Université de Rennes 1, Campus de Beaulieu Bâtiment 11A, 263 av. Général Leclerc, 35042 Rennes Cedex, France.
Summary
Investigating granular flows on smooth inclined channels reveals complex behaviors like convection and inverted density profiles. These findings challenge previous assumptions and offer insights into granular dynamics on flat boundaries.
Area of Science:
- Physics
- Geophysics
- Engineering
Background:
- Granular flows on inclined channels are prevalent in natural and industrial settings.
- Most studies focus on bumpy boundaries to prevent sliding, leaving smooth boundaries less explored.
- Understanding granular flow dynamics on flat surfaces is crucial for various applications.
Purpose of the Study:
- To investigate granular flows down inclined channels with smooth boundaries.
- To quantitatively validate numerical simulations against experimental results.
- To explore complex flow behaviors at larger inclination angles.
Main Methods:
- Numerical simulations of individual grains and side walls.
- Comparison of simulation results with experimental data.
- Testing a simple viscoplastic rheological model in an averaged form.
Main Results:
- Numerical simulations accurately reproduced experimental findings for smooth boundaries.
- At larger angles, granular convection and inverted density profiles were observed.
- Flows on flat bases were analogous to flows over an effective bumpy base, showing Bagnold-type profiles.
Conclusions:
- Smooth boundaries exhibit rich behaviors, including potential Rayleigh-Bénard type instabilities.
- A simple viscoplastic rheological model effectively captures the transition between unidirectional and convective flows.
- The study provides a deeper understanding of granular flow mechanics on flat surfaces.
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