Investigation of Flow Behavior and Heat Transfer Performance in Liquid-cooled TPMS Lattice Structures

Triply periodic minimal surface (TPMS) lattice structures have been widely studied in thermal management due to their very high heat transfer capability, favorable flow characteristics, and design flexibility in liquid cooling systems. This paper studies the fluid flow and heat transfer characteristics of six TPMS unit cells: Diamond (D), Fischer-Koch S (FKS), FRD, Gyroid (G), I-WP, and Primitive (P). These structures have hydraulic diameters in the range of 5.26-11.30 mm, and they are studied under flow conditions spanning a Reynolds number range of 526-10170. In addition, the mechanisms of through-hole types and flow path tortuosity, and a selection framework of unit cell is established based on the evaluation metrics. The obtained results demonstrate that the descending order of the heat transfer efficiency is: FRD, Fischer-Koch S (FKS), Diamond (D), Gyroid (G), I-WP, and Primitive (P). That of the fluid pressure drop is: FRD, Fischer-Koch S (FKS), Primitive (P), Gyroid (G), Diamond (D), and I-WP. As for the thermal and hydraulic performance, the descending order is given by: Diamond (D), Fischer-Koch S (FKS), I-WP, Gyroid (G), FRD, and Primitive (P). It can then be deduced that, although the FRD model has the highest heat transfer performance, it also exhibits a very high pressure drop. The Fischer-Koch S (FKS) and Diamond (D) models exhibit a higher balance between thermal efficiency and flow resistance, which demonstrates their higher applicability in engineering practice. On the contrary, the Gyroid (G), I-WP, and Primitive (P) models, characterized by through-hole features, are more suitable for rapid fluid transport scenarios with low heat transfer demands, such as pipeline systems.