Abstract: Twin-fluid atomization by gas and liquid has been widely used in the modern industry. Few studies have been conducted on the three-fluid atomizer. A test rig using a nozzle was constructed to explore the atomization characteristics of glycerol/water/compressed air spray. Spray patterns were captured by a high-speed camera, while droplet diameter and particle velocity were measured by a phase Doppler particle analyzer (PDPA). The relationships between the air-liquid ratio (ALR) and the atomization spatial properties, including droplet Sauter diameter and mean velocity, were investigated. It is found that droplet Sauter diameter varies slightly with ALR in the range from 0.327 to 0.518. Droplet diameter and velocity show strong non-uniformity in the spray field. Near the nozzle exit droplet diameter decreases rapidly while droplets are accelerated leading to higher droplet velocity. At different axial positions, the atomization effects show a similar trend that the atomization is finer in the center area of the spray than in the margin.

Key words: three fluid atomization, droplet diameter and velocity, glycerol, gas-assisted fluid atomization