Driven granular gases with gravity

Abstract

We study fluidized granular gases in a stationary state determined by the balance between an external driving and the bulk dissipation. The two considered situations are inspired by recent experiments, where the gravity plays a major role as a driving mechanism: in the first case gravity acts only in one direction and the bottom wall is vibrated, in the second case gravity acts in both directions and no vibrating walls are present. Simulations performed under the molecular chaos assumption show averaged profiles of density, velocity and granular temperature which are in good agreement with the experiments. Moreover we measure the velocity distributions which show strong non-Gaussian behavior, as experiments pointed out, but also density correlations accounting for clustering, at odds with the experimental results. The hydrodynamics of the first model is discussed and an exact solution is found for the density and granular temperature as functions of the distance from the vibrating wall. The limitations of such a solution, in particular in a broad layer near the wall injecting energy, are discussed.

Revised version accepted for publication. New results added and discussions considering tangential forces. 27 pages (19 figures included), to appear in Phys.Rev.E

References in corpus (6)

• Clustering and Non-Gaussian Behavior in Granular Matter
• Non-Gaussian velocity distributions in excited granular matter in the absence of clustering
• A kinetic approach to granular gases
• Energy flows in vibrated granular media
• Temperature scaling in a dense vibro-fluidised granular material
• Phase Changes in an Inelastic Hard Disk System with a Heat Bath under Weak Gravity for Granular Fluidization

Cited by in corpus (12)

• Size separation in vibrated granular matter
• Inelastically scattering particles and wealth distribution in an open economy
• Collision statistics of driven granular materials
• Clustering transitions in vibro-fluidized magnetized granular materials
• The dynamics of thin vibrated granular layers
• Driven low density granular mixtures
• Local Equation of State and Velocity Distributions of a Driven Granular Gas
• Temperature inversion in granular fluids under gravity
• Numerical simulation of vibrated granular gases under realistic boundary conditions
• Models of fluidized granular materials: examples of non-equilibrium stationary states
• Fluctuating hydrodynamics in a vertically vibrated granular fluid with gravity
• A qualitative Langevin-like model for the coexistence of two distinct granular temperatures