Size segregation in granular media induced by phase transition
arXiv:cond-mat/0505724 · doi:10.1103/PhysRevLett.95.078001
Abstract
In order to study analytically the nature of the size segregation in granular mixtures, we introduce a mean field theory in the framework of a statistical mechanics approach, based on Edwards' original ideas. For simplicity we apply the theory to a lattice model for hard sphere binary mixture under gravity, and we find a new purely thermodynamic mechanism which gives rise to the size segregation phenomenon. By varying the number of small grains and the mass ratio, we find a crossover from Brasil nut to reverse Brasil nut effect, which becomes a true phase transition when the number of small grains is larger then a critical value. We suggest that this transition is induced by the effective attraction between large grains due to the presence of small ones (depletion force). Finally the theoretical results are confirmed by numerical simulations of the 3d system under taps.
Submitted to Phys. Rev. Lett
References in corpus (18)
- The Bethe lattice spin glass revisited
- The Reverse Brazil Nut Problem: Competition between Percolation and Condensation
- Lattice Glass Models
- Edwards measures for powders and glasses
- Equilibrium phase behavior of polydisperse hard spheres
- Granular segregation as a critical phenomenon
- Dynamical response functions in models of vibrated granular media
- Segregation in a fluidized binary granular mixture: Competition between buoyancy and geometric forces
- Tapping Spin Glasses
- A Statistical Mechanics Approach to the Inherent States of Granular Media
- Equilibrium Distribution of the Inherent States and their Dynamics in Glassy Systems and Granular Media
- Glass transition in granular media
- Variational Approach to Hard Sphere Segregation Under Gravity
- Thermodynamics and statistical mechanics of frozen systems in inherent states
- Segregation in hard spheres mixtures under gravity. An extension of Edwards approach with two thermodynamical parameters
- Gases, liquids and crystals in granular segregation
- Metastable states of the Ising chain with Kawasaki dynamics
- Segregation in fluidized versus tapped packs