Turbulent convection in the zero Reynolds number limitM. Breuer and U. Hansen
Institut für Geophysik, Westfälische Wilhelms-Universität Münster - 48149 Münster, Germany, EU
received 5 September 2008; accepted in final form 29 March 2009; published April 2009
published online 6 May 2009
We discuss thermal convection in the infinite Prandtl number limit. This is relevant for convection in planetary interiors, where inertia of momentum is neglegible, i.e., the Reynolds number of the flow is zero. By means of a numerical two-dimensional model of Rayleigh-Bénard convection, we investigate the evolution of a flow at the Rayleigh number (Ra = 108) and demonstrate that even in this zero Reynolds number limit convection exhibits key features of turbulent flow, commonly addressed to high Reynolds number convection. Special attention is given to the phenomenon of reversals in the orientation of the underlying large-scale circulation of the flow. Our case study indicates that flow reversals are an intrinsic feature of turbulent thermal convection resulting from competing states whose main modes turn out to be solutions of the underlying stationary equations.
47.27.te - Turbulent convective heat transfer.
47.20.Bp - Buoyancy-driven instabilities (e.g., Rayleigh-Benard).
47.27.ek - Direct numerical simulations.
© EPLA 2009