Clustering instability in granular gases: A mesoscopic investigation
We present a numerical study of the density fluctuations in granular flows in the hydrodynamic limit. By simulating the continuum equations posed for granular flows,(1,2) we study the onset of the density-cluster formation. Clusters are observed when the restitution coefficient of granular collision is sufficiently small. However, unlike the clusters seen in molecular dynamics simulations,(3,4) these macroscopic clusters appear to be transient. In the long time limit, they are damped by the viscous dissipation.
granular flow kinetic theory boltzmann equation bgk model