Numerical and experimental MHD studies of Lead-Lithium liquid metal flows in multichannel test-section at high magnetic fields

Numerical simulation and experiments have been performed at high magnetic fields (1-3T) to study the MHD assisted molten Lead-Lithium (PbLi) flow in a model test-section which has typical features of multiple parallel channel flows as foreseen in various blanket module of ITER. The characteristics Hartmann number of the presented case study is up to 1557 which is relevant to typical fusion blanket conditions. Symbols B-0, a, sigma, mu in the definition of Hartmann number are strength of the applied magnetic field, characteristic length scale which is half the channel width parallel to the magnetic field, electrical conductivity and dynamic viscosity of PbLi respectively. Flow distribution in two electrically coupled parallel channels that are fed from a common inlet manifold has been analyzed by measuring the side wall potential difference data of individual channels and by numerical simulation. Both the results of numerical prediction and measured flowrate indicate unequal distribution in parallel channels and the variation is a function of the total flowrate and applied magnetic field strength. Also 3-D currents generated due to the complex geometrical flow path play a key role in distribution of the flow among the parallel channels. A similarity coefficient (K) is proposed for quantitative estimation of the similarity between numerical and corresponding experiment data of wall potential distribution. The measured pressure drop in the test-section is analyzed for different flow conditions to verify the applicability of laminar flow model.