Magnetohydrodynamic flows in u-shaped ducts under a uniform transverse magnetic field

In this study, the three-dimensional liquid metal (LM) magnetohydrodynamic (MHD) flows in a u-shaped duct under a uniform magnetic field applied perpendicular to the flow plane are numerically analyzed with the use of commercial software CFX. The u-shaped duct system is made up of an inflow channal, an outflow channal and a connecting channel located between the inflow channel and outflow channel. In the current study, the effects of the length of the connecting channel and the conductance ratio on the flow characteristics are investigated. Higher velocities are observed in the side layers of the inflow, outflow and connecting channels, forming "M-shaped" velocity profiles. In addition, the velocity recirculations are created in the inner regions of the two right-angle segments just after turning due to the inertial force therein, yielding complicated distributions of the current and electric potential, and found are the diverging and converging of the velocity component parallel to the magnetic field when fluids are turning. The results show that the pressure drop is in close relationship with the conductance ratio and the length of the connecting channel. The characteristics of the fluid velocity, current, electric potential and pressure gradient of LM MHD flows in a u-shaped duct are examined in detail.