Atoms in the Surf: Molecular Dynamics Simulation of the Kelvin-Helmholtz Instability using 9 Billion Atoms

TL;DR

This paper demonstrates a large-scale molecular dynamics simulation of Kelvin-Helmholtz instability in molten metals, revealing detailed vortex formation and complex mixing at atomic scales.

Contribution

It presents one of the largest molecular dynamics simulations of fluid instability, using 9 billion atoms to visualize vortex evolution at atomic resolution.

Findings

Vortices grow from atomic fluctuations under shear.

Complex vortical structures and secondary instabilities observed.

Detailed atomic-level mixing phenomena captured.

Abstract

We present a fluid dynamics video showing the results of a 9-billion atom molecular dynamics simulation of complex fluid flow in molten copper and aluminum. Starting with an atomically flat interface, a shear is imposed along the copper-aluminum interface and random atomic fluctuations seed the formation of vortices. These vortices grow due to the Kelvin-Helmholtz instability. The resulting vortical structures are beautifully intricate, decorated with secondary instabilities and complex mixing phenomena. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.