Simulations of driven overdamped frictionless hard spheres

Universality of jamming criticality in overdamped shear-driven frictionless disks.

We investigate the criticality of the jamming transition for overdamped shear-driven frictionless disks in two dimensions for two different models of energy dissipation: (i) Durian's bubble model with dissipation proportional to the velocity difference of particles in contact, and (ii) Durian's "mean-field" approximation to (i), with dissipation due to the velocity difference between the partic...

Event-driven Brownian dynamics for hard spheres.

Brownian dynamics algorithms integrate Langevin equations numerically and allow to probe long time scales in simulations. A common requirement for such algorithms is that interactions in the system should vary little during an integration time step; therefore, computational efficiency worsens as the interactions become steeper. In the extreme case of hard-body interactions, standard numerical i...

Confined packings of frictionless spheres and polyhedra

By means of numerical simulations, we study the influence of confinement on three-dimensional random close packed (RCP) granular materials subject to gravity. The effects of grain shape (spherical or polyhedral) and polydispersity on this dependence are investigated. In agreement with a simple geometrical model, the solid fraction is found to decrease linearly for increasing confinement no matt...

Molecular dynamics simulations of crystallization of hard spheres.

We have carried out molecular dynamics simulations of the crystallization of hard spheres modeling colloidal systems that are studied in conventional and space-based experiments. We use microscopic probes to investigate the effects of gravitational forces, polydispersity, and of bounding walls on the phase structure. The simulations employed an extensive exclusive particle grid method and the t...

Plane shear flows of frictionless spheres: Kinetic theory and 3D soft-sphere discrete element method simulations