Transitional and turbulent flows driven by a rotating magnetic field

K. Fraňa^1,2 - J. Stiller¹ - R. Grundmann¹

¹ Institute for Aerospace Engineering (ILR), Technische Universität Dresden, D-01062 Dresden, Germany
² Technical University of Liberec, Department of Power Engineering Equipment, Czech Republic

Abstract
The isothermal turbulent flow driven by a rotating magnetic field in a closed cylindrical container was examined numerically by means of direct numerical simulation (DNS) and two-equation turbulence models. We present here a comparative study of the flows, which were computed under axisymmetric and non-axisymmetric assumptions. The deviations between the results obtained are discussed with respect to magnetically induced mean velocities, normal Reynolds stresses and turbulence kinetic energy, in particular. The non-stationary k-ω SST model yielded the best results of all axisymmetric approaches under consideration and can be recommended for engineering applications of stirring processes. In contrast, the standard k-ε model has proved to be too diffusive for the discussed type of flow. Tables 1, Figs 8, Refs 21.