Clustering and fluidization in a one-dimensional granular system: Molecular dynamics and direct-simulation Monte Carlo method - art. no. 041302

We study a one-dimensional granular gas of pointlike particles not subject to gravity between two walls at temperatures T-left and T-right. The system exhibits two distinct regimes, depending on the normalized temperature dif ference Delta = (T-right- T-left)/( T-right + T-left): one completely fluid ized and one in which a cluster coexists with the fluidized gas. When Delta is above a certain threshold, cluster formation is fully inhibited, obtain ing a completely fluidized state. The mechanism that produces these two pha ses is explained. In the fluidized state the velocity distribution function exhibits peculiar non-Gaussian features. For this state, comparison betwee n integration of the Boltzmann equation using the direct-simulation Monte C arlo method and results stemming from microscopic Newtonian molecular dynam ics gives good coincidence, establishing that the non-Gaussian features obs erved do not arise from the onset of correlations.