Fluid Flow and Heat Transfer Performances of Aluminum Alloy Lattices with Triply Periodic Minimal Surfaces

Thermal protection systems play a pivotal role in astronautical engineering fields. However, traditional rectangular fin (RF) structures exhibit low thermo-fluid properties. Inspired by the minimal surfaces in nature, this study develops three types of triply periodic minimal surface (TPMS) lattices, namely, sheet primitive (SP), network I-WP (NW), and sheet I-WP (SW) by using mathematical formulae. The TPMS lattices are fabricated by laser powder bed fusion using AlSi10Mg powder. A convective heat transfer simulation model of TPMS lattices is established and validated through experiments. The fluid flow characteristics, heat transfer characteristics, and overall heat transfer performance of the TPMS lattices are comprehensively investigated based on the simulation model. Results show that the relationship between pressure loss and flow velocity of the TPMS lattices satisfies the Darcy-Forchheimer law. Compared to traditional RF structures, the TPMS lattices exhibit a more uniform temperature distribution at the same flow rate, and the highest convective heat transfer coefficient is increased by approximately 96.62%. This is due to the complex internal structures of the TPMS lattices, which enhance the disturbance of the fluid flow and further improve the heat transfer coefficient. The overall thermal transfer index (α) of the TPMS lattices is higher than that of traditional RF structures with an order of αSP>αSW>αNW>αRF, which confirms the potential applications of TPMS lattices in thermal protection systems.