Affiliations: Institute for Aerospace Engineering, TU Dresden,
D-01062 Dresden, Germany. E-mail: frana@tfd.mw.tu-dresden.de
Abstract: Taylor-Görtler vortices play an important role in the flow driven by
rotating magnetic field in a closed cylindrical container. The visualization of
these structures is essential to understand their physics and their impact on
the dynamics of the flow. We present a study of various methods for identifying
vortex cores, including the so-called λ_2 and Q criteria. While
λ_2 is, probably, the better indicator it is more sensitive to
numerical noise and thus less effective in devising 3D vortex structures. Here,
the Q criterion proved particularly useful when applied to the fluctuation
velocity field.