Numerical investigation into thermo-hydraulic characteristics and mixing performance of triply periodic minimal surface-structured heat exchangers

The expansive specific area and intricate tortuous topology of triply periodic minimal surfaces (TPMS), which evenly partition three-dimensional space into two separate yet interwoven domains, rendering them highly promising candidates for heat exchanger configurations. Furthermore, advancements in additive manufacturing technology have broken through the limitations of traditional manufacturing methods, enabling the fabrication of triply periodic minimal surfaces no longer out of reach. In this study, a three-dimensional, steady-state, conjugate heat transfer numerical model based on OpenFOAM is developed to compare the performance of four TPMS-structured heat exchangers with that of conventional compact heat exchangers across four dimensions: heat transfer, flow resistance, volume, and weight. Additionally, the flow characteristics within TPMS-structured heat exchangers are investigated. It was discovered that the overall performance evaluation coefficient of three TPMS structures, i.e., Gyroid, Diamond, and IWP, increased by 90–110% compared to printed circuit heat exchanger within Re range of 200–500. This can be attributed to the “merge-split” phenomenon within the channel which enhances both flow mixing and heat transfer. Furthermore, the mixing performance of TPMS structures fluid channels was visualized, quantified, and compared to heat transfer capacity.