Liquid metal magnetohydrodynamic flows in an electrically conducting rectangular duct with sudden expansion

In this paper, three dimensional liquid metal (LM) magnetohydrodynamic (MHD) flows in a rectangular duct with sudden expansion are examined. Computational fluid dynamics simulations are performed to predict the behavior of the MHD flows in the duct. Here, the flow velocity, current density, electric potential, pressure drop and Lorentz force in the flow field are elucidated to investigate the influence of the duct expansion and magnetic field direction on the MHD flows. The magnetic fields applied parallel and perpendicular to the direction of the expansion are considered in two different cases, respectively. In the former case a thin velocity recirculation region is predicted just after the expansion, however, in the latter case fairly large velocity recirculation regions are observed with complicated electric potential distribution therein.