Investigations of magnetohydrodynamic (MHD) coupling duct flows are important for liquid metal blankets of fusion reactors. In this study, numerical simulations are performed to systematically clarify the influence of the inclined transversal magnetic fields on the MHD flow states such as pressure gradients and velocity distributions through two coupling ducts with conducting walls. It is found that the MHD coupling effect in the co-flow case is much weaker than that in the counter-flow case. The inclined transversal magnetic fields have an obvious influence on the velocity distributions in the MHD coupling duct flows especially for the counter-flow case, which will induce large reversal flow regions. The inclined transversal magnetic fields will also have a significant impact on the pressure gradients in the two coupling ducts in the counter-flow case, for instance, the MHD coupling effect is so strong that the pressure gradients in the coupling ducts are several even dozens of times bigger than that in a single duct. The aspect ratio of the coupling ducts affects the MHD coupling effect significantly in the counter-flow case, and the coupling effect will be strengthen as the aspect ratio decreases. A special MHD coupling effect is firstly found, because of this effect the pressure gradients in the coupling ducts of the counter-flow case decrease with the increase of the coupling Hartmann wall thickness.
MHD flows through ferromagnetic rectangular ducts in liquid metal blankets