AI Summary & Key Takeaways
AI InsightThe findings provide new insights into the physics of aluminium atomization and mechanisms governing droplet breakup.
📌 3 Key Takeaways
Abstract
Gas atomization is a widely applied method for metal powder production, particularly for additive manufacturing, due to its ability to produce spherical particles with controlled size distribution. In this study, computational fluid dynamics was employed to investigate the atomization of molten aluminium using argon gas at inlet pressures of 2.5, 3.0, 3.5, and 3.7 MPa. The k–ε RNG turbulence model was used to analyse key gas flow phenomena such as Prandtl–Meyer expansion waves, Mach disks, shock waves, turbulence layers, circulation zones, and stagnation points. Flow separation was observed at 2.5 MPa, while the highest kinetic energy occurred at 3.7 MPa. Notably, the circulation region and stagnation point remained nearly unaffected by pressure variation. Two-phase simulations with the volume of fluid method revealed that the stagnation point, where velocity approaches zero, represents a potential site for satellite droplet formation. Primary atomization generated liquid films, ligaments, and droplets of ~500 µm–1 mm, while secondary atomization proceeded through sequential breakup stages. In this study, the fragmentation of a single droplet is systematically tracked, with breakup stages classified and related to the surrounding gas flow dynamics. The findings provide new insights into the physics of aluminium atomization and mechanisms governing droplet breakup.
Özet
Gas atomization is a widely applied method for metal powder production, particularly for additive manufacturing, due to its ability to produce spherical particles with controlled size distribution. In this study, computational fluid dynamics was employed to investigate the atomization of molten aluminium using argon gas at inlet pressures of 2.5, 3.0, 3.5, and 3.7 MPa. The k–ε RNG turbulence model was used to analyse key gas flow phenomena such as Prandtl–Meyer expansion waves, Mach disks, shock waves, turbulence layers, circulation zones, and stagnation points. Flow separation was observed at 2.5 MPa, while the highest kinetic energy occurred at 3.7 MPa. Notably, the circulation region and stagnation point remained nearly unaffected by pressure variation. Two-phase simulations with the volume of fluid method revealed that the stagnation point, where velocity approaches zero, represents a potential site for satellite droplet formation. Primary atomization generated liquid films, ligaments, and droplets of ~500 µm–1 mm, while secondary atomization proceeded through sequential breakup stages. In this study, the fragmentation of a single droplet is systematically tracked, with breakup stages classified and related to the surrounding gas flow dynamics. The findings provide new insights into the physics of aluminium atomization and mechanisms governing droplet breakup.