Dynamics of clustering in freely cooling granular fluid

Abstract

Via the event-driven molecular-dynamics simulations, we have studied the structure and dynamics in a model granular fluid of hard discs in space dimension d = 2. Inelastic collisions among these discs lead to clustering, resembling the kinetics in a vapor-liquid phase transition. The structural growth of these clusters are quantified via an application of finite-size scaling theory. We also present results for the decay of the kinetic energy. Discussion on the validity of a scaling argument, connecting the latter with the time dependence of clustering, is provided. Further, a striking difference in the finite-size effects of the kinetics with those of the phase transition dynamics is pointed out.