Hydrodynamic Character of the Non-equipartition of Kinetic Energy in Binary Granular Gases

TL;DR

This study uses molecular dynamics simulations to explore how different heating mechanisms affect the kinetic energy distribution in binary granular gases, revealing that non-equipartition persists independently of the energy injection method.

Contribution

It demonstrates that the non-equipartition of kinetic energy in granular mixtures is unaffected by the heating mechanism, except near boundaries, and that bulk properties are described without partial temperatures.

Findings

Non-equipartition persists regardless of energy injection method.

Bulk state characterized by variables excluding partial temperatures.

Boundary layer effects are localized near the vibrating wall.

Abstract

The influence of the heating mechanism on the kinetic energy densities of the components of a vibrated granular mixture is investigated. Collisions of the particles with the vibrating wall are inelastic and characterized by two coefficients of normal restitution, one for each of the two species. By means of molecular dynamics simulations, it is shown that the non-equipartition of kinetic energy is not affected by the differential mechanism of energy injection, aside the usual boundary layer around the wall. The macroscopic state of the mixture in the bulk is defined by intensive variables that do not include the partial granular temperatures of the components.