Breakup simulation fo a viscous liquid using a coaxial high-speed gas jet

This paper presents numerical simulations of the atomization of viscous liquids, focusing on the combination of the liquid breakup and droplet transport processes. Coaxial high-speed gas jet created by a High Volume Low Pressure (HVLP) spray gun was used. The VOF-to-DPM model, namely coupled Volume of Fluid and Lagrangian particle tracking approaches, was applied. Secondary breakup model was also applied. Effect of breakup models and grid size on the droplet distribution was studied. The intact liquid length close to the liquid nozzle and the formation of liquid droplets in the regions of primary and fully developed breakup along the spray jet and the spray angle directions were analysed. The Sauter mean diameter distribution and the droplet-velocity correlation downstream the nozzle were compared with experimental results.