Modelling of the break up mechanism in gas atomization of liquid metals. Part I: The surface wave formation model

An integrated model of the atomization of a liquid column perturbed by a flowing gas phase is proposed. The algorithm termed Surface Wave Formation (SWF) is based on the concept of the formation of sinusoidal waves travelling along the surface of the liquid. The amplitude of such instabilities can grow exponentially under specific conditions, effectively causing the detachment of liquid particles either by shearing of part of a wave crest or by detachment of a liquid body at negative amplitude nodes. The SWF model covers both primary and secondary atomization and can in principle describe the break up of any well-defined liquid shape. Model predictions compare favourably with experimental data from close coupled atomization of metals. The implications of the SWF algorithm are important, since—unlike empirical correlations—it can predict the size distribution of particles inside a spray in space and atomization time. Future integration could include calculations of cooling histories of drops in flight.