Nanohydrodynamics simulations: An atomistic view of the Rayleigh–Taylor instability

Nanohydrodynamics simulations, hydrodynamics on the nanometer and nanosecond scale by molecular dynamics simulations for up to 100 million particles, are performed on the latest generation of supercomputers. Such simulations exhibit Rayleigh-Taylor instability, the mixing of a heavy fluid on top of a light in the presence of a gravitational field, initiated by thermal fluctuations at the interface, leading to the chaotic regime in the long-time evolution of the mixing process. The early-time behavior is in general agreement with linear analysis of continuum theory (Navier-Stokes), and the late-time behavior agrees quantitatively with experimental observations. Nanohydrodynamics provides insights into the turbulent mixing process that are inaccessible to either continuum calculations or to experiment.