Optimal Design of the Liquid Metal Feeding System for Fusion Reactor Blankets through High-Fidelity MHD Simulations*

PbLi is the liquid metal (LM) used in the fusion reactor blanket for Tritium breeding and blanket cooling. The conventional LM feeding system design involves two separate inlet and outlet pipes, while the advanced design opts for two coaxial pipes to save space. Given that the blanket is subjected to a strong magnetic field within the fusion reactor, the LM flow experiences a significant magnetohydrodynamics (MHD) pressure drop. A well-designed feeding system will reduce this pressure drop and enhance flow uniformity to avoid underfed blanket channels.

 

In 2010, 2D MHD simulations were conducted for LM feeding systems. However, 3D effects have not been well analyzed. This work uses COMSOL to conduct 3D high-fidelity MHD simulations of the LM feeding systems. Firstly, the MHD flow results in the inlet/outlet pipes are validated against a classic analytical solution. Then, simulations are conducted for the entire LM feeding system, including the inlet manifold, blanket poloidal channel, and the outlet manifold. The COMSOL results are compared with existing Open-FOAM simulations for code-to-code verification. Both quantitative and qualitative comparisons are performed. Comprehensive studies cover a wide range of magnetic field strengths (0.1-3 Tesla) and inlet velocities (0.01-0.4 m/s) to identify the optimal design. By characterizing 3D effects, this research provides reliable simulation data for fusion reactor studies and sheds light on the optimal design of the liquid metal feeding system for blankets.