Computational study of the aspect ratio effect on liquid metal flow in a rectangular duct with and without magnetic field

Z. Tigrine^1,2 - S. Lecheheb^1,3 - A. Bouabdallah¹ - F. Mokhtari¹ - A. Kharicha⁴

¹ Faculté de Physique, Laboratoire de Thermodynamique et Systèmes Energétiques, Université des sciences et de la technologie Houari Boumediene (USTHB), BP32 El Alia,16111Bab Ezzouar, Alger, Algeria
² Unité de Développement des Equipements Solaires, UDES/Centre de Développement, des Energies Renouvelables, CDER, Bou-Ismail 42415, W.Tipaza, Algeria
³ Centre de Développement des Energies Renouvelables, Route de l'Observatoire BP 62 Bouzareah 16340
⁴ Department of Metallurgy, Montanuniversität Leoben, University of Leoben, Franz-Josef-Str. 18

Abstract
We present a numerical investigation of the three-dimensional geometry effect on liquid metal flows in a rectangular duct subject to a transverse magnetic field using miniature cylinders immersed in fluid. Simulations are performed by means of a numerical method based on the finite volume method. The considered liquid metal is the 17Li83Pb eutectic alloy evolving in a rectangular channel. The influence of forced convection and magnetic field is studied. Streamwise counter rotating vortices are created in a spanwise direction by small devices intended for controlling the secondary flow near the wall region. It is found that the mushroom structure dominates in the flow at a low Reynolds number Re_h ≤ 272. With a large Reynolds number, the flow regime is unstable downstream the duct showing horseshoe vortex patterns. By increasing the aspect ratio of the rectangular duct, the onset of steady streaks is delayed. Key words: Magnetohydrodynamics, liquid metal, numerical simulations, aspect ratio. Tables 1, Figs 8, Refs 26.