Computational study of free surface film flow and subsequent disintegration of a sheet and ligaments into droplets from a rotary disk atomizer

In the present study, a computational methodology based on computational fluid dynamics (CFD) is developed to investigate free surface film flow and its subsequent disintegration on a rotary disk atomizer. The present study provides an insight into efficiently modeling both liquid film formation and its subsequent disintegration. The presented computational methodology can easily be reproduced and can act as a benchmark for the modeling of liquid film formation as well as the disintegration phenomenon. The influence of disk speed, liquid flow and feed arrangement on the rotating disk are investigated. The film thickness profile on the disk resembles the formation of spiral waves at 500 RPM and an irregular breakup of the spiral waves for a disk speed of 1000 RPM. At higher speeds, a smooth and thin liquid film is observed on the disk. Offset feeding of the liquid on the disk alters the wave formation and breakup of the spiral waves. It is found that ligaments are formed at the lip of the disk owing to Rayleigh–Taylor instability, whereas liquid sheet breakup is due to combined rim and wave disintegration for the parameters investigated in this study.