Fluctuations in the Uniform Shear Flow state of a granular gas

TL;DR

This paper investigates the energy fluctuations in a granular gas under uniform shear flow using kinetic theory, revealing their coupling with pressure tensor fluctuations and validating predictions with molecular dynamics simulations.

Contribution

It provides explicit expressions for energy and pressure tensor fluctuation correlations in two dimensions, advancing understanding of granular gas behavior under shear flow.

Findings

Good agreement between theory and simulations for inelasticity range

Explicit correlation expressions derived for 2D case

Fluctuations are coupled to pressure tensor components

Abstract

We study the fluctuations of the total internal energy of a granular gas under stationary uniform shear flow by means of kinetic theory methods. We find that these fluctuations are coupled to the fluctuations of the different components of the total pressure tensor. Explicit expressions for all the possible cross and auto correlations of the fluctuations at one and two times are obtained in the two dimensional case. The theoretical predictions are compared with Molecular Dynamics simulation and a good agreement is found for the range of inelasticity considered.