Thermal-hydraulic performance of modified Schwartz-Diamond solid-networks triply periodic minimal surface structures

The triply periodic minimal surface (TPMS) structures are widely used as disturbance core structure in high performance heat exchangers. In this paper, four modified Schwartz-Diamond solid-networks (SD-solid) TPMS structures, one structure compressed along the flow direction (β = 2), and three structures compressed along the spanwise direction (α = 2, α = 3, and α = 4) are designed. Flow and heat transfer processes in the structures are studied with computational fluid dynamics (CFD) and experimental method. The performance enhancement criterion (PEC) is employed to evaluate the overall heat transfer performance. As the results of simulation, the overall heat transfer coefficient (hoverall) of α = 2, α = 3, and α = 4 is 10.04 %, 34.34 %, and 62.03 % higher than that of SD-solid respectively. The PEC of α = 2, α = 3, and α = 4 structures is 27.35 %, 34.17 %, and 34.95 % higher than that of the original SD-solid structure, respectively. Two samples of them (β = 2 and α = 2) are fabricated using additive manufacturing and their thermal–hydraulic performance is experimented on a flow and heat transfer experimental platform. Comparing the experimental results of the hoverall, the β = 2 structure is 68.5 % higher and the α = 2 structure is 23.06 % higher than the original SD-solid structure. However, for the average pressure drop, the β = 2 structure is 448.5 % higher and the α = 2 structure is 66.77 % lower than the original SD-solid structure. It is proved that the modified SD-solid structure compressed along the spanwise direction has the performance of enhancing heat transfer and reducing the pressure drop.