Computational MHD analyses in support of the design of the WCLL TBM breeding zone

Highlights: • Sudden cross section variation at manifold interface is the most important pressure loss contribution • A scaling law is derived for the TBM loss such that $\Delta p_t=f\left(\text{Ha},N\right)$. • Cooling system has a negligible effect on pressure loss under the assumption of forced convection. The Water-Cooled Lithium Lead (WCLL) is a blanket concept pursued in the framework of Test Blanket Module (TBM) campaign in ITER. Even if the liquid metal is circulated slowly in the component, magnetohydrodynamic (MHD) pressure losses are still expected to be significant. The aim of this paper is to assess the MHD pressure losses in the TBM frontal part, also called Breeding Zone (BZ). There, important contributions are caused by the manifold interface, the presence of cooling pipes obstructing the fluid movement, a sharp hairpin bend, and non-uniform wall thickness of the walls. Direct numerical simulation of 2D and 3D MHD flows is used to estimate the head loss for each one of these elements. A scaling law is derived to allow quick estimate of the pressure loss from reference parameters. The main contribution to the head loss is caused by the windows that connect the BZ with the manifold.