Energy transfer process in gas models of Lennard-Jones interactions

TL;DR

This study uses simulations to show that energy transfer in Lennard-Jones gas models occurs ballistically rather than diffusively, challenging previous assumptions and suggesting new experimental approaches.

Contribution

It demonstrates through simulations that energy transfer in Lennard-Jones gases is ballistic, contrasting with the commonly assumed diffusive process.

Findings

Energy propagates ballistically in 2D and 3D Lennard-Jones gases.

Contrasts with the Gaussian diffusion model widely assumed.

Proposes experimental methods to verify the ballistic transfer.

Abstract

We perform simulations to investigate how the energy carried by a molecule transfers to others in an equilibrium gas model. For this purpose we consider a microcanonical ensemble of equilibrium gas systems, each of them contains a tagged molecule located at the same position initially. The ensuing transfer process of the energy initially carried by the tagged molecule is then exposed in terms of the ensemble-averaged energy density distribution. In both a 2D and a 3D gas model with Lennard-Jones interactions at room temperature, it is found that the energy carried by a molecule propagates in the gas ballistically, in clear contrast with the Gaussian diffusion widely assumed in previous studies. A possible scheme of experimental study of this issue is also proposed