Generating a tide-like flow in a cylindrical vessel by electromagnetic forcing

Abstract

We show and compare numerical and experimental results on the electromagnetic generation of a tide-like flow structure in a cylindrical vessel which is filled with the eutectic liquid metal alloy GaInSn. Fields of various strengths and frequencies are applied to drive liquid metal flows. The impact of the field variations on amplitude and structure of the flows are investigated. The results represent the basis for a future Rayleigh-Bénard experiment, in which a modulated tide-like flow perturbation is expected to synchronize the typical sloshing mode of the large-scale circulation. A similar entrainment mechanism for the helicity in the Sun may be responsible for the synchronization of the solar dynamo with the alignment cycle of the tidally dominant planets Venus, Earth and Jupiter.

Shaken and stirred: When Bond meets Suess-de Vries and Gnevyshev-Ohl

“…Strong empirical evidence for a phase coherent 11.07-year Schwabe cycle comes both from algae data in the early Holocene (Vos et al, 2004), and from 14 C and 10 B data for the last 600 years (Stefani et al, 2020b). We note in passing that the numerical models produce, via the resonant dependence of the α-effect on the magnetic field strength, also secondary peaks of solar activity, which might be linked to mid-term oscillations (Obridko and Shelting, 2007;Valdés-Galicia and Velasco, 2008;McIntosh et al, 2015; Bazilevskaya et al, 2016;Karak, Mandal and Banarjee, 2018;Frick et al, 2020).…”

“…A test of the same concept in the simplified framework of an m = 1 buoyancy instability of toroidal flux rings, as developed by Ferriz Mas, Schmitt, and Schüssler (1994), could be very helpful and instructive in this respect. Interestingly, helicity synchronization with an m = 2 forcing was numerically observed for the physically different, but topologically similar case of an m = 1 large scale circulation of Rayleigh-Bénard convection in a cylinder (Galindo, 2020). A liquid metal experiment to confirm this effect is presently under way (Stepanov and Stefani, 2019;Jüstel et al, 2020).…”

“…Interestingly, helicity synchronization with an m = 2 forcing was numerically observed for the physically different, but topologically similar case of an m = 1 large scale circulation of Rayleigh-Bénard convection in a cylinder (Galindo, 2020). A liquid metal experiment to confirm this effect is presently under way (Stepanov and Stefani, 2019;Jüstel et al, 2020).…”