Rayleigh–Taylor turbulence in strongly coupled dusty plasmas

Abstract

The turbulence mixing initiated by the Rayleigh–Taylor instability has been reported in a two-dimensional (2D) strongly coupled dusty plasma system using classical molecular dynamics simulation. The entire evolution cycle, including the initial equilibrium, the instability, turbulent mixing, and, finally, a new equilibrium through the thermalization process, has been demonstrated via the respective energy spectra. The fully developed spectrum follows the Bolgiano-Obukho k−11/5 scaling at smaller wavenumbers, a characteristic 2D buoyancy-driven turbulent flow feature. At higher wavenumbers, the energy spectrum E(k)∝k represents the thermalization of the system and is a characteristic feature of 2D Euler turbulence. At longer timescales, the system reflects the Kolmogorov scale of k−3. Moreover, strong coupling slows the turbulent mixing process, though the final state is a complete thermalized system. Our results also help us to understand the thermalization process in Yukawa fluids, other strongly coupled plasma families, and turbulent mixing in low Reynolds number fluids.