We investigate hydrodynamic noise in a dilute granular gas during the homogeneous cooling state, by means of a proper application of the direct simulation Monte Carlo (DSMC) algorithm. The DSMC includes a source of randomization which is not present in molecular dynamics (MD) for inelastic hard disks. Notwithstanding this difference, a fair quantitative agreement is found, including a violation of the fluctuation-dissipation relation for the noise amplitude of the same order observed in MD. This study suggests that deterministic collision dynamics is not an essential ingredient to reproduce, up to a good degree of approximation, hydrodynamic fluctuations in dilute granular gases.
Fluctuating hydrodynamics for dilute granular gases: a Monte Carlo study
Giulio Costantini;Andrea Puglisi
2010
Abstract
We investigate hydrodynamic noise in a dilute granular gas during the homogeneous cooling state, by means of a proper application of the direct simulation Monte Carlo (DSMC) algorithm. The DSMC includes a source of randomization which is not present in molecular dynamics (MD) for inelastic hard disks. Notwithstanding this difference, a fair quantitative agreement is found, including a violation of the fluctuation-dissipation relation for the noise amplitude of the same order observed in MD. This study suggests that deterministic collision dynamics is not an essential ingredient to reproduce, up to a good degree of approximation, hydrodynamic fluctuations in dilute granular gases.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.