Effect of contact resistance on liquid metal MHD flows through circular pipes

Abstract

Effect of contact resistance on magnetohydrodynamic (MHD) laminar flows through circular pipes are investigated by numerical simulations. A numerical method is proposed to investigate this issue. This method is that the induced magnetic field is individually calculated through two different governing equations in the liquid and the solid domains, special boundary conditions are given considering effects of the contact resistance. This method is validated by comparing with analytical solution and another numerical method. Numerical results of the velocity distribution and the MHD pressure drop affected by the contact resistance through circular pipes are given. It is shown that the contact resistance has a significant impact on the MHD pressure drop under the conditions of the fusion liquid metal blanket , and normally, the big contact resistance as a result of poor wetting can cause the MHD pressure drop to be several times lower than no contact resistance case. In addition, non-uniform contact resistance will cause the jet instability in the Robert layer and form a larger jet near the area of contact resistance. In the end, numerical results are compared with experimental results which include the effect of non-uniform contact resistance on the velocity distribution; it is indicated that numerical results are in good agreement with experimental results and validates that the larger velocity jet will be caused by the non-uniform contact resistance from experimental results.