Numerical and experimental observations of the flow field inside a selective laser melting (SLM) chamber through computational fluid dynamics (CFD) and particle image velocimetry (PIV)

Collection and recycling of the metal powders ejected from the working plane are the primary objectives for improving the selective laser melting (SLM) process. The flow behaviors through the SLM working chamber are obviously significant and must be further studied to resolve these matters. In this study, we continued the studies presented previously to design a blow-to-suction device enlarged from 250 mmx250 mm to 500 mmx500 mm. The air curtain inside the SLM working chamber, instead of a parallel flow, was designed with a vertical downward blowing jet as well as two parallel suction devices. Computational and experimental fluid dynamics were conducted to simulate the flow field through the working chamber, using blowing nozzles of various shapes. Particle image velocimetry (PIV) was applied to investigate the flow field and to further verify the simulation results. The flow velocity profiles inside the chamber measured via PIV agreed well with those obtained through CFD simulation. (C) 2019 Elsevier B.V. All rights reserved.