Effects of Inclined Gradient Magnetic Field on the Liquid Metal Flow States Through Coupled Conducting Ducts

The liquid metal magnetohydrodynamic (MHD) flow through coupled ducts with conducting walls under inclined transversal gradient magnetic field is an important physical flow phenomenon, which has the unknown physical mechanism about the interaction between the electromagnetic coupling effect and the three-dimensional (3D) MHD effect. To reveal this physical mechanism, 3D numerical simulations based on a customized solver in the OpenFoam environment are conducted to systematically study the effect of inclined gradient magnetic field on the MHD flow states through coupled conducting ducts. Then the mechanism behind the generation of the 3D MHD effect in the gradient magnetic field zones has been discussed in detail. It is found that the electromagnetic coupling effect can enhance this 3D MHD effect in the co-flow case, but suppress it in the counter-flow case. Moreover, the strong electromagnetic coupling effect in the counter-flow case will induce a “self-circulation” flow region in the duct when the external magnetic field is inclined, and the inclined angle also has a great influence on the area of this flow region, which reduces with the increase of the inclined angle. These results are important for the in-depth fundamental understanding of the 3D MHD effect of liquid metal flowing through coupled conducting ducts under inclined gradient magnetic field, and also helpful for the future design of the liquid metal blanket of fusion reactor.