Experimental performance comparison between a gyroid-based triply periodic minimal surface (TPMS) heat exchanger and a commercial plate heat exchanger

Conventional compact heat exchangers (HXs) often face a trade-off between thermal efficiency and pressure drop, which motivates the exploration of novel geometries. This study proposes a gyroid-structure-based triply periodic minimal surface (TPMS) HX, fabricated using metal additive manufacturing (AM). The performance of the TPMS HX was evaluated under liquid-liquid conditions and experimentally compared with that of a commercial brazed plate heat exchanger (BPHE). In addition, the influence of flow direction on the TPMS HX capacity was investigated, showing up to a 15 % improvement due to the sustained temperature difference between the hot and cold streams along the flow paths. Experimental results demonstrated that the TPMS HX achieved overall heat transfer coefficients ( U ) up to 4.4 % higher than those of the tested PHE. The TPMS HX also exhibited wholly turbulent flow at lower Reynolds numbers ( Re ), while its friction factor ( f ) was up to 30.5 % lower over the same Re range. Performance comparisons were conducted by j / f ¹ᐟ³ and the thermal performance factor (TPF) which is the heat transfer rate divided by the total pumping power of the fluids. The j / f ¹ᐟ³ values of the TPMS heat exchanger were higher than or comparable to those reported in the literature for conventional BPHEs, and approximately 7 % higher than those of the tested BPHE in this study. These findings highlight the potential of the TPMS structure as a high-performance HX capable of replacing conventional HXs.