Transition of an electromagnetically driven liquid metal flow from laminar to turbulent in a toroidal square duct
1 Department of Mechanical Engineering, University of Thessaly - 38334 Volos, Greece, EU
2 Department of Energy Technology, Technological Educational Institute of Athens - 12210 Athens, Greece, EU
Received: 13 November 2012
Accepted: 1 February 2013
The electromagnetically driven liquid metal flow in a toroidal duct of a square cross-section is studied numerically searching for the critical Reynolds (Re) and Hartmann (Ha) numbers where transition occurs. Results are reported for Ha up to 500, building a transition map of critical Reynolds and Hartmann numbers and showing two distinct regimes of transition signified by the destabilization of the secondary flow: The first, for Ha < 18, where the Lorentz force is balanced by fluid momentum diffusion and the second, for Ha ⩾ 18, where it is balanced by fluid inertia. In both cases, the destabilization of the secondary flow occurs primarily near the concave sidewall. For Ha ⩾ 18 the transition follows approximately the relationship Re = 16.803 Ha1.43 for values of Re and Ha in the range 80 < Re/Ha < 224.
PACS: 47.27.Cn – Transition to turbulence / 47.35.Tv – Magnetohydrodynamic waves
© EPLA, 2013