Topological design of open-cell microstructure with optimal effective thermal conductivity

The highly thermal conductive porous structure has many application scenarios, such as the skeletons embedded with phase change material. The additive manufacture technique combined with topology optimization motivates the design of microstructure of lattice material. A topology optimization framework based on isotropic material with penalization and finite element is developed. Aiming at extremely high thermal conductivity, the optimal lattices have closed pores. The conductivity is close to the theoretical Hashin-Strikman bound. In order to achieve the goal of open-cell lattice for heat and mass transport, a multi-objective function based on thermal conductivity and mass diffusivity is proposed. Optimization results reveal that various microstructure has optimal effective properties which are close to theoretical cross-property bound. In addition, the lattice materials are fabricated using selective laser melting. The experimental thermal conductivity results are in good agreement with the numerical simulation, with an error of less than 8%. The ability to fabricate the microstructure accurately provides an opportunity to use these lattice materials. This work provides a basis for designing lattice material, with better application in skeleton embedded with PCM, lattice channel, lattice heat sink, etc. & COPY; 2023 Elsevier Ltd. All rights reserved.

Automated summary

A topology optimization framework based on isotropic material is developed to design highly thermal conductive porous structures. The study shows that by optimizing the microstructure, it is possible to achieve thermal conductivity and mass diffusivity close to theoretical bounds. The selective laser melting technique enables the accurate fabrication of the microstructure of these lattice materials.