Investigating turbulence in strongly coupled dusty plasma using molecular dynamics simulations

The turbulence dynamics of dusty plasma flows, governed by strong long-range Coulomb interactions between particles, remains inadequately understood. In this paper, we simulate two-dimensional (2D) (KHI) and (RTI) turbulence in dusty plasma using the molecular dynamics (MD) Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) code. The intermediate wavenumbers of these flows exhibit k-3 and k-11/5 spectra, respectively. However, both flows exhibit a thermalized E(k)∝k spectrum at large wavenumbers. The wavenumber range of thermalization extends towards lower values, ultimately reflecting a new thermal equilibrium. We also demonstrate that mixing and thermalization are delayed with an increase in the strength of the Coulomb coupling. Furthermore, we identify qualitative similarities between strongly coupled dusty plasma turbulence and elastic turbulence, including a steeper kinetic-energy spectrum at higher coupling strengths. Results highlight MD as a capable numerical tool for modelling complex turbulent flows. It provides particle-resolved insight into complex turbulent flows, and a means to study flows where appropriate continuum (fluid) descriptions are not available. This article is part of the theme issue ‘Frontiers of turbulence and statistical physics’.