Simulates a two-dimensional system of hard disks confined to a box. Confined Hard Disk System is an idealized statistical mechanics model that simulates a two-dimensional system of hard disks confined to a box with a constant temperature thermal reservoir at one end and a movable piston at the other. Slow-moving particles are color-coded as blue and fast particles are color-coded as yellow. The model computes and plots the time evolution of the kinetic energy K per particle, the pressure P, and the volume V. The model also displays histograms and mean values of these quantities.

Particles in this model have unit mass and interact through pairwise contact forces and hard-wall contact forces. Newton's equations of motion are integrated using the Cash-Karp 5(4) ODE solver until a hard disk-disk or disk-wall collision is detected by an ODE event. The time evolution is then paused, the impulse approximation is used to compute new velocities, the time evolution is resumed. The model allows users to change the boundary conditions to simulate a constant energy microcanonical ensemble and a constant temperature canonical ensemble.

Requirements:
* Java

The license of this software is Free, you can free download and free use this graphing software.