Design, manufacture, and thermal-hydraulic performance investigation of multi-type triply periodic minimal surface structures

The triply periodic minimal surface (TPMS) structures hold significant promise for enhancing thermal-hydraulic performance in compact heat exchangers. However, a systematic comparison of various TPMS types and optimization strategies under unified standards is lacking, hindering rational selection for engineering applications. This study experimentally and numerically investigates the performance of seven TPMS structures, encompassing basic types (Diamond, IWP, Gyroid, and Primitive), structural strategies (sheet vs solid networks), hybridization, and cell density enhancement. A key finding is the significant deviation of additively manufactured samples from their designs, with an average pressure drop of the realized Primitive-sheet structure being 22.96% higher than its ideal counterpart. More importantly, the results reveal a fundamental performance trade-off: solid-network TPMS structures (exemplified by IWP-solid-1) excel in flow efficiency, reducing pressure drop by an order of magnitude compared to their sheet-network counterparts, while sheet-network structures (particularly the Diamond-sheet) achieve superior heat transfer coefficients, up to 104.42% higher than the Primitive-sheet. Hybridization of the Gyroid and Primitive sheets demonstrated a potential pathway for pressure drop reduction. Crucially, evaluation based on the area goodness factor (j/f) identified the Diamond-sheet and IWP-solid-1 as the top performers for overall thermal-hydraulic efficiency among sheet and solid networks, respectively. This study provides direct guidance and critical data for selecting and optimizing the TPMS structures in thermal management systems.