Turbulent Rotating Rayleigh-Bénard Convection

Stephan S, Hansen U

Abstract

Convectively driven, rotating turbulence is ubiquitous in geo- and astrophysical systems. Here, we investigate the rotating Rayleigh-Be ́nard system by means of direct numerical simulations. Our simulation results allow us to establish scaling relationships for the heat transport which can be readily applied to a broad class of geophysical and astrophysical systems. In particu- lar, we identify two different dynamical regimes: one in which rotation dominates and where the Nusselt number Nu scales approximately as Nu ∼ Ra6/5, and one in which the heat transfer is not affected by rotation and where hard-turbulence behaviour with Nu ∼ Ra2/7 is observed. We further hypothesize that the transition from the rotation dominated regime to the hard turbulence regime is tied to boundary layer dynamics, in sharp contrast to widely used global force balance arguments.