Review and comparison of turbulent convective heat transfer in state-of-the-art 3D truss periodic cellular structures

Abstract

To promote the development and application of periodic cellular structures (PCSs), this paper reviews and systematically compares the heat transfer and pressure drop of state-of-the-art 3D truss PCSs. Relative merits among these PCSs in the turbulent regime are clarified which have been fuzzy in the open literature. The topological and orientation effects on the thermo-fluids of the PCSs are also investigated. Twelve PCSs with the same height and porosity, separately in two different orientations, are evaluated by numerical simulations. These PCSs include the cubic lattice (CL), the body-centered cubic lattice (BCCL), the face-centered cubic lattice (FCCL), octet lattice (OL), circular pyramid lattice (CPL), rectangular pyramidal lattice (RPL), tetrakaidecahedron lattice (TL), X-lattice (XL), shifted X-lattice (SXL), circular tetrahedral lattice (CTL), rectangular tetrahedral lattice (RTL), and Kagome lattice (KL). It is found that the entry and exit effects on heat transfer and pressure drop are limited within the first four unit cells and the last unit cell, respectively. For a given Reynolds number within the range of 2692–11087, the SXL in orientation A (SXL-OA in abbreviation) exhibits the best overall heat transfer; and the SXL-OA also has the best endwall heat transfer. In addition, the OL-OA, XL-OA and SXL-OA show the best heat transfer on the PCS core. In terms of pressure drop for a given Reynolds number, the RTL-OA and RTL-OB exhibits the highest and the lowest pressure drop, respectively. For a given pumping power, the OL exhibits the best overall heat transfer. Thermo-fluidic mechanisms are also explored with representative PCSs. For the given porosity and range of Reynolds number, correlations for overall heat transfer, local heat transfer and pressure drop are presented, which are beneficial for engineers to quickly evaluate and compare the PCSs made of different materials. The systematic comparison in the turbulent regime extends the comparison in the laminar regime in the open literature, which is expected to promote reasonable development and application of PCSs in heat exchangers and thermal management systems. Applications of PCSs in different scenarios and future work are also commented.