The Ideal 2D Gas with Gravity simulation shows the motion of a 2-dimensional ideal gas with N particles confined in an vertical strip of the 2-d Euclidean space, under the action of a constant gravitational field. At t=0 the the gas is far from its equilibrium state: the initial position distribution is uniform in a certain orthogonal region of the strip. The velocities of the particles have random directions and their magnitudes are identical. Because of the particle-particle (p-p) interactions(8,9) and under the action of the gravitational field, the system is moving towards its state of equilibrium.

A supplemental pdf document describes the theoretical model of the 2-dimensional gas and derives the probability distribution in the phase space, which determines its equilibrium state. The time sequence of the position distributions converge to the "exponential atmosphere" and that of the velocities to the Maxwell-Boltzmann distribution. The gas converges to its equilibrium state which is well-defined and independent of the initial state of the gas. In the simulation, we can watch the evolution of the gas towards its equilibrium state. Uses can observe the dependence of the equilibrium position-distribution on the strength of the gravitational field. They can also carry out measurements in the virtual environment, and compare the achieved results with their theoretical predictions.

Evolution of Ideal 2D Gas Documentation
A supplemental pdf document describes the theoretical model of the 2-dimensional gas and derives the probability distribution in the phase space, which determines its equilibrium state. download 241kb .pdf
Last Modified: February 17, 2022

Evolution of Ideal 2D Gas with Gravity EJS Source Code
Source code for Evolution of Ideal 2D Gas with Gravity JS Model. Open this file using the JavaScript version of EJS. download 290kb .zip
Last Modified: February 17, 2022
Released under a CC Noncommercial-Share Alike 4.0 license.

K. Papamichalis, Evolution of Ideal 2D Gas with Gravity JS Model (2022), <https://www.compadre.org/Repository/document/ServeFile.cfm?ID=15993&DocID=5541>.

Papamichalis, K. (2022). Evolution of Ideal 2D Gas with Gravity JS Model. Retrieved November 28, 2023, from https://www.compadre.org/Repository/document/ServeFile.cfm?ID=15993&DocID=5541

Papamichalis, Kostas. Evolution of Ideal 2D Gas with Gravity JS Model. 2022. https://www.compadre.org/Repository/document/ServeFile.cfm?ID=15993&DocID=5541 (accessed 28 November 2023).

@misc{
Author = "Kostas Papamichalis",
Title = {Evolution of Ideal 2D Gas with Gravity JS Model},
Volume = {2023},
Number = {28 November 2023},
Year = {2022}
}

%A Kostas Papamichalis %T Evolution of Ideal 2D Gas with Gravity JS Model %D 2022 %U https://www.compadre.org/Repository/document/ServeFile.cfm?ID=15993&DocID=5541 %O text/html

%0 Electronic Source %A Papamichalis, Kostas %D 2022 %T Evolution of Ideal 2D Gas with Gravity JS Model %V 2023 %N 28 November 2023 %9 text/html %U https://www.compadre.org/Repository/document/ServeFile.cfm?ID=15993&DocID=5541

Disclaimer: ComPADRE offers citation styles as a guide only. We cannot offer interpretations about citations as this is an automated procedure. Please refer to the style manuals in the Citation Source Information area for clarifications.

Use the Easy Java Simulations Modeling and Authoring Tool to edit and to explore the source code for the Evolution of a 2-dimensional ideal gas in a constant gravitational field toward the state of equilibrium.