A numerical simulation of gas flow field effects on high pressure gas atomization due to operating pressure variation

High pressure gas atomization is emerging as an efficient method of producing high yields of ultrafine metal and alloy powders. The results of a numerical study of the gas-only flow field of a high pressure, confined feed, annular jet gas-metal atomizer are compared with experimental data and are reported in this paper. The axisymmetric, turbulent, compressible Navier-Stokes equations are solved for the gas-only flow in the vicinity of the melt tip. A parametric variation of gas atomizing pressure and its effect on gas flow field is examined. The numerical results demonstrate the existence of a strong recirculation region, mixing layer, and shock structures downstream of the melt tip in good agreement with experimental observations and past studies. The paper focuses on the characterization of the flow field, including a comparison of numerical and experimental data and how the results support a droplet formation mechanism over a range of atomizing pressures.