Optimization design and heat transfer investigation of TPMS compact heat exchanger based on field synergy principle

Abstract

The rapid development of additive manufacturing (AM) has made it possible to produce compact heat exchangers with triply periodic minimal surface (TPMS) structures. However, although original TPMS type heat exchangers offer the advantages of both porous and biomimetic structures, there is still room for optimization in terms of compactness and efficiency. This study designed a G-D type TPMS heat exchanger based on the field synergy principle, combining the advantages of two fundamental TPMS structures (Gyroid and Diamond) to enhance fluid velocity and temperature gradient synergy throughout the heat exchanger, thus strengthening heat transfer. A prototype G-D heat exchanger was successfully fabricated using 3D printing technology and characterized by CT imaging. Computational fluid dynamics (CFD) simulations and experiments were conducted to compare the flow and heat transfer performance of the G-D heat exchanger with that of the original TPMS heat type exchanger. Flow and heat transfer correlations for the G-D heat exchanger were derived using the least-squares fitting method. The dimensionless factor j/f^1/3 was used to evaluate the overall performance of the heat exchanger. Results showed that the G-D heat exchanger exhibited significantly improved heat transfer efficiency and compactness compared to traditional and original TPMS type heat exchangers, with a heat transfer rate per unit volume of 604.4 W/cm³ under a temperature difference of 40 °C. This study offers valuable guidance for the fusion of different TPMS structures and the design of efficient, compact heat exchangers.