A Rayleigh B\'enard Convective Instability Study Using Energy Conserving Dissipative Particle Dynamics

TL;DR

This study uses energy conserving dissipative particle dynamics to simulate Rayleigh Bénard convection, revealing pattern formation and density changes consistent with previous gas studies, with implications for understanding convective instabilities.

Contribution

First simulation of Rayleigh Bénard instability using energy conserving dissipative particle dynamics in three dimensions.

Findings

Observation of two cell pattern beyond critical temperature difference

Formation of high density layers near the cold wall at higher temperatures

Pattern invariance with domain length doubling

Abstract

A Rayleigh B\'enard instability study using the energy conserving dissipative particle dynamics method is presented here for the first time. The simulation is performed on an ideal dissipative particle dynamics fluid in a three dimensional domain with carefully selected parameters to make the convection terms in the equation more dominant than the conduction ones. Beyond a critical temperature difference a two cell pattern is observed as the dominant structure. As the temperature is increased further, the density changes in the system are sharp with formation of distinct high density layers close to the cold wall. Doubling the length of the domain led to the formation of four convection cells with the same cell diameter as before, confirming the invariance of the pattern formation in that dimension. Changes in the height of the domain led to cells with more uniform looking patterns. The results and patterns seen here are qualitatively similar to previous studies performed on rarefied gases.