Experimental Study on Flow and Thermal Transport in Additively Manufactured Architectured Lattice Frame With Air and Particles as Convective Agents

An experimental study is conducted to characterize the flow and thermal transport in additively manufactured lattice structures, with air and particles as convective agents. Four different lattice topologies, octet, body-centered cubic (BCC), tetrakaidecahedron (TKD), and pin fins, were additively manufactured using the binder jet additive manufacturing method with stainless steel 316L as the material. The configuration included a single column of 10 inline and interconnected unit cells in the flow direction. The unit cell inscribing different topologies was a cube of edge length 10 mm. The unit cells had a fixed design porosity of 0.88 for each topology, which resulted in different strut diameters for each topology. Due to additive manufacturing (AM)-induced irregularities, the porosities of the printed parts deviated from the intended value for each configuration. Air-based forced convection experiments were conducted for channel hydraulic diameter-based Reynolds numbers ranging from 5000 to 20,000. Flow and heat transfer results have been presented in terms of porosity-based scaled flow velocity. Particle-based forced convection experiments were conducted at a fixed particle mass flux of 47.8 kg/m² s while maintaining a packed-bed movement of particles. In addition to conjugate heat transfer experiments, optical flow experiments were conducted to understand the behavior of moving packed bed of particles near the endwall. For air-based convection, Octet and TKD exhibited a high heat transfer coefficient, while the BCC lattice was better in terms of thermal-hydraulic performance. For particle-based convection, Octet topology yielded the highest convective heat transfer rates.