- Proceeding Paper
This study employed Large Eddy Simulation (LES) based on the WALE model to study the complex flow within a 5 × 5 fuel rod bundle channel with a spacer grid. The numerical simulation was validated through turbulent kinetic spectrum analysis and comparison of axial and radial velocity distributions with experiments. Furthermore, a reduced-order surrogate model was constructed based on the Proper Orthogonal Decomposition (POD) for geometric optimization of the spacer grid mixing vanes. Results show that the optimized structure improves lateral mixing and heat transfer efficiency, and exhibits a more uniform temperature distribution downstream of the spacer grid. This study validates the feasibility of combining LES and POD for efficient optimization of fuel assembly structural design.
Eng. Proc.
21 October 2026





