Numerical simulation of tidal synchronization of the large-scale circulation in Rayleigh--Bénard convection with aspect ratio 1

S. Röhrborn¹ - P. Jüstel¹ - V. Galindo¹ - F. Stefani¹ - R. Stepanov²

¹ Department of Magnetohydrodynamics, Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
² Institute of Continuous Media Mechanics, Russian Academy of Science, 1 Acad. Korolyov str. 1, 614013 Perm, Russia

Abstract
A possible explanation for the apparent phase stability of the 11.07-year Schwabe cycle of the solar dynamo was the subject of a series of recent papers [1-3]. The synchronization of the helicity of an instability with the azimuthal wavenumber m = 1 by a tidal m = 2 perturbation played a key role here. To analyze this type of interaction in a paradigmatic setup, we study a thermally driven Rayleigh-Bénard convection of a liquid metal under the influence of a tide-like electromagnetic forcing. As shown previously, the time-modulation of this forcing emerges as a peak frequency in the m = 2 mode of the radial flow velocity component. In this paper, we present new numerical results on the interplay between the large-scale circulation of a Rayleigh-Bénard convection flow and the time modulated electromagnetic forcing. Key words: Magnetohydrodynamics, Rayleigh-Bénard convection, liquid metal flow, electromagnetic forcing, CFD. Figs 7, Refs 10.