Collision statistics in sheared inelastic hard spheres

Marcus N. Bannerman, Thomas E. Green, Paul Grassia, Leo Lue

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The dynamics of sheared inelastic-hard-sphere systems is studied using nonequilibrium molecular-dynamics simulations and direct simulation Monte Carlo. In the molecular-dynamics simulations Lees-Edwards boundary conditions are used to impose the shear. The dimensions of the simulation box are chosen to ensure that the systems are homogeneous and that the shear is applied uniformly. Various system properties are monitored, including the one-particle velocity distribution, granular temperature, stress tensor, collision rates, and time between collisions. The one-particle velocity distribution is found to agree reasonably well with an anisotropic Gaussian distribution, with only a slight overpopulation of the high-velocity tails. The velocity distribution is strongly anisotropic, especially at lower densities and lower values of the coefficient of restitution, with the largest variance in the direction of shear. The density dependence of the compressibility factor of the sheared inelastic-hard-sphere system is quite similar to that of elastic-hard-sphere fluids. As the systems become more inelastic, the glancing collisions begin to dominate over more direct, head-on collisions. Examination of the distribution of the times between collisions indicates that the collisions experienced by the particles are strongly correlated in the highly inelastic systems. A comparison of the simulation data is made with direct Monte Carlo simulation of the Enskog equation. Results of the kinetic model of Montanero et al. [J. Fluid Mech. 389, 391 (1999)] based on the Enskog equation are also included. In general, good agreement is found for high-density, weakly inelastic systems.
LanguageEnglish
Article number041308
Number of pages10
JournalPhysical Review E
Volume79
Issue number4
DOIs
Publication statusPublished - 22 Apr 2009

Fingerprint

Hard Spheres
Collision
statistics
Statistics
collisions
velocity distribution
Velocity Distribution
shear
Enskog Equation
simulation
Direct Simulation Monte Carlo
molecular dynamics
Molecular Dynamics Simulation
collision rates
fluids
data simulation
stress tensors
normal density functions
Hard-sphere Fluid
Coefficient of restitution

Keywords

  • compressibility
  • gaussian distribution
  • liquid theory
  • molecular dynamics method
  • Monte Carlo methods
  • statistical mechanics

Cite this

Bannerman, Marcus N. ; Green, Thomas E. ; Grassia, Paul ; Lue, Leo. / Collision statistics in sheared inelastic hard spheres. In: Physical Review E. 2009 ; Vol. 79, No. 4.
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Collision statistics in sheared inelastic hard spheres. / Bannerman, Marcus N.; Green, Thomas E.; Grassia, Paul; Lue, Leo.

In: Physical Review E, Vol. 79, No. 4, 041308, 22.04.2009.

Research output: Contribution to journalArticle

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