Numerical modelling of droplet break-up for gas atomisation

High-pressure gas atomisation (HPGA) technology has been widely employed as an effective method to produce fine spherical metal powders. The physics of gas atomisation is dominated by rapid momentum and heat transfer between the gas and melt phases, and further complicated by break-up and solidification. A numerical model is developed to simulate the critical droplet break-up during the atomisation. By integration of the droplet break-up model with the flow field generated high-pressure gas nozzle, this numerical model is able to provide quantitative assessment for atomisation process. To verify the model performance, the melt stream is initialized to large droplets varying from 1 to 5 mm diameters and injected into the gas flow field for further fragmentation and the break-up dynamics are described in details according to the droplet input parameters.