The Research Of Maxwell's Demon On Granular Media Driven By External Force

Based on the Maxwell Demon experiment, a dilute compartmentalized granular materials in a gravitational field shaken vertically is investigated by some numerical simulations.The simulated system is confined in an open box contains N circular particles. The box is divided into two equally sized compartments by a wall which has a hole at finite height. The bottom of the box has a simple harmonic vibration. The initial speed and position of the particles are given randomly. All particles move as paraboloid manner in the simulation. It's the first time that this way is advanced in the research of granular materials. We got some results with this method as follows:1. The granular system consisting of two species of particles has a cyclic oscillation similar to the chemical oscillations—the two species of particles cluster alternately in the two compartments. This is consistent with experiment result qualitatively. However, the stability of the phenomenon needs to be investigated farther.2. When the system is composed of a species of particles with the same diameter located at one compartment initially, there is atemporary alternate cluster-----the particles cluster alternately inthe two compartments, but some time later the phenomenon suddenly disappears and is replaced by the uniform distribution inthe two compartments.3. According to the experiment results, the granular materials made up of a species of particles with different diameters is found to cluster competitively: The grains cluster in the compartment initially containing mainly big particles, for high frequency. The grains cluster in the one containing mainly small particles, for low frequency.