2008/09/25 by J. Javier Brey, J Javier Brey, M. J. Ruiz-Montero +1
Engineering · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Equipartition theorem #Granular flow and fluidized beds #Granular material #Kinetic energy #Kinetic theory #Limit (mathematics) #Nonlinear Photonic Systems #Particle (ecology) #Piston (optics) #Work (physics) #cond-mat.stat-mech
paper · pdf · doi:10.1088/1742-5468/2008/09/l09002
arxiv created 2008/09/25 · openalex publication_date 2008/09/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
The steady state velocity fluctuations of a movable piston located on the top of a vibrated granular gas are studied by means of molecular dynamics simulations. From the second moment of the distribution, a temperature parameter for the piston is defined and compared with the granular temperature of the gas located just below it. Then the two temperature parameters refer to two interacting macroscopic systems. The equipartition of energy valid in usual molecular systems is strongly violated and the temperature of the piston can be larger or smaller than that of the gas, depending on the parameters defining the system at the particle level. The simulation results for the ratio of temperatures are in agreement with some theoretical predictions from kinetic theory, assuming the validity of a hydrodynamic description in the limit of weak inelasticity of the gas.