Temporally heterogeneous dynamics in granular flows.

Area of Science:

• Physics
• Complex Systems
• Materials Science

Background:

• Dense granular flows exhibit complex behaviors influenced by particle interactions.
• Understanding particle-scale dynamics is crucial for modeling macroscopic flow properties.
• The transition to a static state in granular materials shares similarities with phase transitions in other systems.

Purpose of the Study:

• To investigate particle-scale dynamics in gravity-driven, dense granular flows.
• To characterize the temporal heterogeneity and intermittency of granular motion.
• To explore the relationship between granular flow dynamics and supercooled liquid behavior.

Main Methods:

• Utilized granular simulations to model particle dynamics.
• Analyzed particle motion across short, intermediate, and long time scales.
• Characterized intermittent dynamics using structural events and contact network analysis.

Main Results:

• Identified intermittent, temporally heterogeneous dynamics as granular flows approach the angle of repose.
• Observed that a characteristic time scale increases as the flow approaches a stopped state.
• Found that large-scale structural events, where the contact network spans the system, characterize this intermittency.

Conclusions:

• The intermittent dynamics observed in dense granular flows share similarities with the behavior of supercooled liquids near the glass transition.
• The study provides insights into the fundamental mechanisms governing the cessation of granular flow.
• Granular simulations serve as a valuable tool for probing complex dynamics in condensed matter systems.