Conjugate thermo-hydraulic evaluation of triply periodic minimal surfaces and pin fins

• Fischer-Koch S outperforms pin fins with an 87.5% improvement in heat transfer. • Fischer-Koch S surpasses pin fins by 6% − 28.4% in the overall performance. • Fischer-Koch S is the most cost-effective among the five heat sinks. • The irreversibility of the TPMS channel flow is more pronounced than pin fins. • Viscous dissipation dominates the irreversibility of TPMS at high mass flow rates . This study investigates the superior heat dissipation performance of triply periodic minimal surface (TPMS) heat sinks through a comparative analysis with pin fins, aiming to provide novel and cost-effective thermal design alternatives. The flow and thermal evolution characteristics were numerically investigated using the finite volume method, and a parametric analysis was conducted to demonstrate the exceptional overall performance of TPMS heat sinks. The results indicate that the fluid velocity increases by up to 24.55%, and the flow direction changes rapidly along the directional channels of TPMS, further enhancing flow mixing and disturbances within the narrow and tortuous passages. Compared with pin fins, the Fischer-Koch S, Gyroid, and I-WP heat sinks achieve improvements in thermal performance of 87.5%, 33.3%, and 19.1%, respectively. Moreover, among the five heat sink configurations evaluated, the Fischer-Koch S heat sink achieves the best overall performance, outperforming pin fins by 6% to 28.4% as the mass flow rate increases. This superior performance is attributed to its unique channel topology that balances thermal performance and hydraulic loss. Furthermore, the irreversibility in TPMS-based heat sinks is more pronounced than in pin fins, due to increased hydraulic losses and enhanced heat transfer. Viscous entropy production is the predominant source of irreversibility in TPMS channel flow at high mass flow rates , necessitating optimization to minimize irreversible entropy generation and enhance the overall performance.