Saúl Piedra, CONACYT-Centro de Ingeniería y Desarrollo Industrial
Aldo Figueroa, Centro de Investigación en Ciencias, Universidad Autónoma del Estado de Morelos

The electromagnetically driven flow in the wide gap of a concentric sphere system is studied numerically. The mainly azimuthal driving Lorentz force is promoted by the interaction of a dc electric current and a dipolar magnetic field. It was found that for a critical electric current an instability occurs and the flow becomes time-dependent. The full three-dimensional picture of this time-dependent flow can be observed using a meridian cut of the helicity isosurfaces, where four connected vortical structures are appreciated, namely a vortex breakdown.