Patterned turbulence as a feature of transitional regimes of magnetohydrodynamic duct flows

D. Krasnov¹ - O. Zikanov² - T. Boeck¹

¹ Institute of Thermodynamics and Fluid Mechanics, Ilmenau University of Technology, 98684 Ilmenau, Germany
² Department of Mechanical Engineering, University of Michigan -- Dearborn, MI 48128-1491, USA

Abstract
We present results of a numerical analysis of transition to turbulence and laminarization processes in magnetohydrodynamic duct flows with a transverse magnetic field. The simulations continue our earlier work [1, 2], where flow regimes with localized turbulent spots near the side walls parallel to the imposed magnetic field have been discovered. The new results extend the analysis to the case of large Reynolds and Hartmann numbers and to ducts of various aspect ratios. The results show good agreement with experiments and confirm that the states with localized turbulent spots are a robust feature of transitional magnetohydrodynamic duct flows. Figs 5, Refs 28.