Enhanced heat transfer of alveolar biomimetic interlaced hollow lattice metastructures

Lattice metastructures, known for superior heat exchange capabilities, are the focus of current research, which aims to maximize heat transfer performance by increasing the specific surface area of porous structures through innovative lattice designs. This study introduces an innovative alveolar biomimetic interlaced hollow lattice metastructure, inspired by interconnected sac-like alveolar structure, to enhance heat transfer efficiency. The metastructure achieves a maximum specific surface area up to 17 mm⁻¹, significantly surpassing that of traditional structures like the TPMS on the same scale. Through thermo-fluidic analysis under forced convection conditions, the critical influence of the metastructure's unique design elements is revealed, including its interlaced lattice configuration, relative density, and pipe geometry, on flow dynamics and heat transfer performance. Results indicate that: (1) the designed metastructure exhibits superior overall heat transfer enhancement compared to the BCC structure, particularly at higher Reynolds numbers (Re). Notably, at Re ≈ 32000, the 45° metastructure demonstrates exceptional heat transfer enhancement, with a Nusselt number of 621.44, 48.8 % higher than BCC structure. (2) Its distinctive morphology induces a highly tortuous spiral primary flow and two distinct secondary flows (two types of vortex pairs). Such complex flow patterns inside and outside the pipes lead to enhanced heat transfer performance.