Hexagonal convection patterns in atomistically simulated fluids

TL;DR

This study uses molecular dynamics simulations to explore pattern formation in Rayleigh-Benard convection, revealing hexagonal and linear convection patterns at the microscopic scale, with detailed analysis of flow and pattern development.

Contribution

First to simulate and analyze hexagonal convection patterns at the atomistic level using large-scale molecular dynamics simulations.

Findings

Hexagonal convection patterns observed in simulations match experimental patterns.

Flow within convection cells characterized at the microscopic level.

Quantitative analysis of pattern development using automated polygon subdivision.

Abstract

Molecular dynamics simulation has been used to model pattern formation in three-dimensional Rayleigh--Benard convection at the discrete-particle level. Two examples are considered, one in which an almost perfect array of hexagonally-shaped convection rolls appears, the other a much narrower system that forms a set of linear rolls; both pattern types are familiar from experiment. The nature of the flow within the convection cells and quantitative aspects of the development of the hexagonal planform based on automated polygon subdivision are analyzed. Despite the microscopic scale of the system, relatively large simulations with several million particles and integration timesteps are involved.