Phase Changes in an Inelastic Hard Disk System with a Heat Bath under Weak Gravity for Granular Fluidization

TL;DR

This study uses numerical simulations to identify three distinct phases in a granular system under gravity and heat bath conditions, revealing unique behaviors different from traditional vibrating beds.

Contribution

It introduces a phase diagram for granular fluidization under weak gravity and heat bath, highlighting phase distinctions via packing fraction and excitation ratio.

Findings

Identified three phases: condensed, fluidized, turbulent.

Phase transitions characterized by packing fraction and excitation ratio.

System behavior differs from conventional vibrating bed models.

Abstract

We performed numerical simulations on a two-dimensional inelastic hard disk system under gravity with a heat bath to study the dynamics of granular fluidization. Upon increasing the temperature of the heat bath, we found that three phases, namely, the condensed phase, locally fluidized phase, and granular turbulent phase, can be distinguished using the maximum packing fraction and the excitation ratio, or the ratio of the kinetic energy to the potential energy.It is shown that the system behavior in each phase is very different from that of an ordinary vibrating bed.