Multifunctional topology optimization design for foreign debris filtration: A case study in the nuclear sector

The integration of topology optimization (TO) and additive manufacturing (AM) is transforming the design and production of advanced multifunctional structures, offering innovative solutions to complex engineering challenges. While these technologies are well-established in the aerospace industry, the present work highlights their synergistic potential within the nuclear sector by redesigning a representative multifunctional bottom nozzle used in nuclear assemblies. Focusing specifically on foreign debris filtration performance, this study introduces, for the first time, a foreign debris filtering constraint by tailoring the design space of the fluid channel according to the characteristic dimensions of foreign debris. Fluid topology optimization is then applied within this customized design space, resulting in a thin-walled filtering lattice that minimizes energy dissipation. Subsequently, continuum topology optimization is utilized to enhance the load-bearing capacity of the supporting structure, revealing a rib-like load transfer path that reinforces the bottom nozzle. Finally, an integrated lightweight design is achieved by tessellating the optimized filtering lattice into the reinforced load-bearing structure. Performance validation shows that the topology-optimized bottom nozzle significantly outperforms traditional design, improving foreign debris filtration by 6.66%, reducing pressure drop by 10.29%, and increasing structural stiffness by 21.95%, demonstrating the promising application potential of this methodology in the nuclear energy sector.