Velocity distributions in dissipative granular gases

TL;DR

This study uses numerical simulations to analyze how velocity distributions in 2D inelastic granular gases depend on restitution coefficient and heating-to-collision ratio, explaining differences between uniform and boundary heating.

Contribution

It provides a theoretical framework linking velocity distribution shapes to key parameters like restitution coefficient and heating/collision ratio in granular gases.

Findings

Velocity distribution shape is primarily governed by restitution coefficient and heating/collision ratio.

Differences between uniform and boundary heating are explained by different limits of the ratio q.

Theoretical predictions align with observed non-Gaussian velocity distributions in experiments.

Abstract

Motivated by recent experiments reporting non-Gaussian velocity distributions in driven dilute granular materials, we study by numerical simulation the properties of 2D inelastic gases. We find theoretically that the form of the observed velocity distribution is governed primarily by the coefficient of restitution $\eta$ and $q=N_H/N_C$, the ratio between the average number of heatings and the average number of collisions in the gas. The differences in distributions we find between uniform and boundary heating can then be understood as different limits of $q$, for $q \gg 1$ and $q \lesssim 1$ respectively.