Collision statistics in a dilute granular gas fluidized by vibrations in low gravity

TL;DR

This experimental study investigates collision statistics in a dilute granular gas under low gravity vibrations, revealing non-linear collision frequency scaling and non-extensive kinetic energy behavior due to inelastic collisions.

Contribution

The paper provides new experimental insights into collision dynamics and energy distribution in dilute granular gases under low gravity conditions, highlighting non-linear effects.

Findings

Collision frequency does not scale linearly with particle number.

Granular temperature is non-extensive and not an intensive property.

Inelastic collisions lead to dissipative effects affecting collision statistics.

Abstract

We report an experimental study of a dilute "gas" of inelastically colliding particles excited by vibrations in low gravity. We show that recording the collision frequency together with the impulses on a wall of the container gives access to several quantities of interest. We observe that the mean collision frequency does not scale linearly with the number N of particles in the container. This is due to the dissipative nature of the collisions and is also directly related to the non extensive behaviour of the kinetic energy (the granular temperature is not intensive).