Lattice structures have attracted increasing attention for heat exchanger applications due to their high surface-to-volume ratios and geometric flexibility. In such systems, heat transfer efficiency is a critical performance metric as it directly affects operating costs. This study systematically investigated the heat transfer efficiency of body-centered cubic lattice structures with airfoil struts fabricated from AlSi7Mg powder via laser powder bed fusion. The test samples were designed by varying key geometric parameters, including strut shape, unit cell arrangement, build orientation, unit cell aspect ratio, core-to-unit cell height ratio, and relative density. Steady-state forced convection experiments were conducted with air as the working fluid. Compared with conventional circular strut lattices, the airfoil lattices showed a significant reduction in the friction factor of up to 76.9%. Although the Nusselt number decreased, the reduction in the friction factor was dominant, leading to an increase in the efficiency index of up to 34.8%. Variations in build orientation, the unit cell aspect ratio, core-to-unit cell height ratio, and relative density influenced both the Nusselt number and the friction factor; however, a notable improvement in the efficiency index was observed only in test samples with increased relative density, within the high-Reynolds number regime. These results demonstrated the superior efficiency of airfoil lattices and highlighted the effects of design parameters.
Park et al. (2026) studied this question.