Optimization studies for a manifold of a liquid metal blanket of a fusion reactor

Abstract

Magnetohydrodynamic (MHD) flows in a manifold of a liquid metal blanket can significantly contribute to the blanket pressure drop, which is a feasibility issue for almost all liquid metal blanket concepts. Here, optimization studies for a prototypic inlet manifold that feature flow expansion are performed for three expansion angles, θ = 45°, 60° and 75°, expansion ratio of 4, and a wide range of Hartmann (Ha) and Reynolds () numbers: 1000<Ha<10,000, and 50<Re<10,000 aiming at the MHD pressure drop reduction and a more uniform flow distribution at the exit of the manifold. The 150 flow cases computed with COMSOL Multiphysics in 3D provide an extended database for the pressure drop coefficient, which was used to construct a correlation for the 3D MHD pressure drop. In addition, many data analyzes were performed to characterize the flow inside the manifold and access the most important flow characteristics, such as the recirculation flow bubble that appears when the liquid metal enters the expansion region and the flow development length as a function of Ha,Re and θ.