Magnetohydrodynamic and thermal analysis of PbLi flows in poloidal channels with flow channel insert for the EU-DCLL blanket

Magnetohydrodynamic (MHD) processes are known to be critically important for the dual coolant lithium lead (DCLL) breeding blanket (BB) concept. In order to minimize the MHD pressure drop in the European DCLL blanket design, the liquid metal breeder (PbLi) is decoupled electrically from the ferritic-martensitic structure (EUROFER) using insulating ceramic-based flow channel inserts (FCIs). The impact of the FCI on the velocity profile and the pressure drop in the DCLL front poloidal channels is studied. Two-dimensional momentum and induction equations for fully developed flows are solved numerically using the ANSYS-Fluent simulation platform under DCLL-relevant conditions (Ha = 7.57 10³, Re = 2.27 10⁴). Velocity and pressure drop in the PbLi flows have been computed first for a channel without FCI and then for three possible alumina-based FCI design: two types of sandwich FCI and one naked FCI. In order to analyze thermal effects in the blanket, the obtained velocity profiles are used as inputs to solve the 3D energy equation. The computations of the temperature distribution in the DCLL poloidal front channel with a prototypical exponentially varying heat generation profile are obtained using convective boundary conditions. Results show the effect of the FCI and MHD phenomena on heat transfer.