Dynamos in precessing cubes

Abstract

We investigate with numerical simulations the dynamo properties of liquid flows in precessing cubes. There are some similarities with the flow in precessing spheres. Instabilities in the form of triad resonances are observed. The flow is turbulent far above the onset of instability but simplifies to a single vortex for certain control parameters. The critical magnetic Reynolds numbers for the onset of magnetic field generation are lower than, but comparable to, the numbers known for precessing spheres, and are larger than the Reynolds numbers realizable in an experiment currently under construction in Dresden.