Thermal and hydraulic behaviours of Kelvin cells from metallic three-dimensional printing

Kelvin cells (KCs) have similar morphological and heat transfer properties as metal foams but more regular structures. Designing a porous structure to improve the overall heat transfer performance is feasible through metallic three-dimensional printing. In the study, the comprehensive comparisons of forced convective heat transfer properties among Kelvin cells (KCs), elliptical Kelvin cells (EKCs), and reversed elliptical Kelvin cells (REKCs) are performed experimentally and numerically. The results indicate that the pressure drop of the EKCs is 38.6% and 57.2% lower than those the KCs and the REKCs, while they own the Nusselt number 10.5% and 4.8% smaller, respectively. However, the area goodness factor of the EKCs is 50.9% and 108.9% higher than those of the other two structures. Therefore, the EKCs have an advantage in hydraulic properties and overall heat transfer performance. A larger flowing space in the cavity and a smaller angle between the vector and skeleton of the EKCs enhance the hydraulic behavior and overall heat transfer performance. The fin characteristics lead to the negligible deviation of thermal properties among the samples. The 1.5 cells are the most efficient height for all samples. The results can shed light on the design of the heat exchanger with Kevin cells.