Flowers in flour: avalanches in cohesive granular matter
E Freyssingeas1, M-J Dalbe, J-C Géminard
1Université de Lyon, Laboratoire de Physique, Ecole Normale Supérieure de Lyon, CNRS, Lyon, France.
Summary
Cohesive granular materials exhibit complex free surface dynamics during silo discharge, with avalanches creating non-axisymmetric craters. Despite this intermittent behavior, the material flow rate remains constant.
Area of Science:
- Physics
- Engineering
Background:
- Granular materials exhibit unique flow properties.
- Silo discharge is a fundamental process in granular flow.
Purpose of the Study:
- Investigate the free surface dynamics of cohesive granular materials during silo discharge.
- Analyze the impact of cohesion on crater formation and flow rate.
Main Methods:
- Experimental observation of silo discharge.
- Analysis of free surface dynamics and crater geometry.
- Measurement of flow rate.
Main Results:
- Cohesion leads to intermittent free surface dynamics and non-axisymmetric crater formation due to avalanches.
- In contrast, non-cohesive materials form stable conical craters.
- The flow rate remains constant despite the intermittent surface behavior.
Conclusions:
- Cohesion significantly alters granular flow dynamics at the free surface.
- The constant flow rate suggests underlying mechanisms that stabilize discharge despite surface intermittency.
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