Abstract: In order to improve the fire safety of ships during navigation, the theoretical model of pressure swirl nozzle was established according to its structural type and working principle. The external droplet atomization characteristics were analyzed by the combination of experiment and numerical simulation, and the effects of inlet pressure, nozzle outlet diameter and swirl chamber length on atomization particle size and atomization cone angle were analyzed. The results showed that the atomization particle size decreased with the increase of the inlet pressure and the length of the swirl chamber, and increased with the increase of the outlet diameter; the atomization cone angle became larger with the increase of the inlet pressure and the outlet diameter, and decreased with the increase of the swirl chamber length. Box-Behnken test was designed and CFD simulation was performed to obtain the influence law of atomization cone angle and atomization particle size by response surface method.

Key words: navigation safety, pressure cyclone flow, atomisation cone angle, atomisation particle size