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

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. Stream-wise 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 Reh ≤ 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.