Propagation of internal deformations in dense granular flows

Area of Science:

• Physics
• Materials Science
• Geophysics

Background:

• Dense granular flows exhibit complex behaviors, including non-locality and transient rheology.
• Understanding local deformation development is crucial for modeling these flows.

Purpose of the Study:

• To analyze the development of local deformation in dense granular flows.
• To investigate the mechanism of deformation propagation and its dependence on the inertial number.

Main Methods:

• Simulated homogeneous shear flows with varying inertial numbers (I).
• Measurement of local kinematic fields: particle velocity fluctuations, local strain, and non-affine deformation.

Main Results:

• Local kinematic fields are unsteady and spatially correlated.
• A propagation mechanism of local deformation was identified, driven by particle rearrangement events.
• Cluster size and propagation velocity increase as a power law of I as I approaches 0.

Conclusions:

• The identified deformation propagation mechanism is key to understanding granular flow behaviors.
• This mechanism provides insights into non-locality and transient rheology in granular materials.
• The strong dependence on the inertial number highlights its critical role in granular flow dynamics.