Velocity correlations in dense granular shear flows: Effects on energy dissipation and normal stress

Namiko Mitarai, Hiizu Nakanishi

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62 Citations (Scopus)

Abstract

We study the effect of precollisional velocity correlations on granular shear flow by molecular dynamics simulations of an inelastic hard sphere system. Comparison of the simulations with kinetic theory reveals that the theory overestimates both the energy dissipation rate and the normal stress in the dense flow region. We find that the relative normal velocity of colliding particles is smaller than that expected from random collisions, and the discrepancies in the dissipation and the normal stress can be adjusted by introducing the idea of the collisional temperature, from which we conclude that the velocity correlation neglected in the kinetic theory is responsible for the discrepancies. Our analysis of the distributions of the precollisional velocity suggests that the correlation grows through multiple inelastic collisions during the time scale of the inverse of the shear rate. As for the shear stress, the discrepancy is also found in the dense region, but it depends strongly on the particle inelasticity.

Original languageEnglish
Article number031305
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Volume75
Issue number3
DOIs
Publication statusPublished - Mar 26 2007

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Granular Flow
Energy Dissipation
Shear Flow
shear flow
energy dissipation
Discrepancy
Kinetic Theory
kinetic theory
Inelastic collision
inelastic collisions
Hard Spheres
Shear Stress
Molecular Dynamics Simulation
shear stress
Dissipation
Time Scales
dissipation
Collision
simulation
molecular dynamics

All Science Journal Classification (ASJC) codes

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics

Cite this

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