2007/01/18 by Baruch Meerson, Manuel Díez‐Minguito, Meerson, Baruch +5
Earth and Planetary Sciences · Engineering · Materials Science · #FOS: Physical sciences #Granular flow and fluidized beds #High-pressure geophysics and materials #Material Dynamics and Properties #Sports Dynamics and Biomechanics #Statistical Mechanics (cond-mat.stat-mech)
paper · pdf · doi:10.48550/arxiv.cond-mat/0701449
openalex publication_date 2007/01/18 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
Dense granular clusters often behave like macro-particles. We address this\ninteresting phenomenon in a model system of inelastically colliding hard disks\ninside a circular box, driven by a thermal wall at zero gravity. Molecular\ndynamics simulations show a close-packed cluster of an almost circular shape,\nweakly fluctuating in space and isolated from the driving wall by a low-density\ngas. The density profile of the system agrees very well with the azimuthally\nsymmetric solution of granular hydrostatic equations employing constitutive\nrelations by Grossman et al., whereas the widely used Enskog-type constitutive\nrelations show poor accuracy. We find that fluctuations of the center of mass\nof the system are Gaussian. This suggests an effective Langevin description in\nterms of a macro-particle, confined by a harmonic potential and driven by a\ndelta-correlated noise. Surprisingly, the fluctuations persist when increasing\nthe number of particles in the system.\n