Measurements of the Velocity of Drops in a Melt Atomization Process Using Particle Image Velocimetry

This paper addresses the measurement of the two-dimensional velocity distribution of ligaments and drops during melt atomization. The result of the atomization process is influenced by numerous parameters and is still not well understood. Also due to the high temperatures involved in the process, in situ measurements are very scarce. Due to the fact that melt atomization is a process that cannot be rapidly repeated, two-dimensional measurement techniques are now the methods of choice. The velocity of the atomized particles is one quantity that can be used for diagnostics and understanding as well as for comparison with numerical studies. The atomization is done using an industrial vacuum inert gas atomization facility. The velocity measurements are performed using particle image velocimetry (PIV). The set-up and the application of this method are described in detail. The data evaluation of the velocity measurements shows only small differences between different metals. The melt jet breaks up into a hollow cone spray at approximately 60mm from the nozzle in both investigated cases. The velocity is there in the range between 120 and 210ms(-1). This result is in good quantitative agreement with numerical results.