Average energy and fluctuations of a granular gas in the threshold of the clustering instability

TL;DR

This paper investigates the energy behavior and fluctuations of a dilute granular gas near clustering instability using fluctuating hydrodynamics and simulations, revealing divergence in energy fluctuations.

Contribution

It combines theoretical predictions with simulations to analyze energy fluctuations and their divergence near the clustering threshold in granular gases.

Findings

Good agreement between theory and simulations

Energy fluctuations diverge as the threshold is approached

Vorticity fluctuations renormalize the total energy

Abstract

The behavior of an isolated dilute granular gas near the threshold of its clustering instability is investigated by means of fluctuating hydrodynamics and the direct simulation Monte Carlo method. The theoretical predictions from the former are shown to be in good agreement with the simulation results. The total energy of the the system is renormalized by the fluctuations of the vorticity field. Moreover, the scaled second moment of the energy fluctuations exhibits a power-law divergent behavior