To understand the primary atomization characteristics of the planar prefilming nozzle

the atomization experiment was carried out to study the influence of different inlet conditions. The high-frequency imaging method of backlight illumination and sheet laser illumination was used to obtain the liquid film breakup morphology in top view and side view. At the same time

the optical image was processed using proper orthogonal decomposition(POD)statistical analysis and the liquid film edge position analysis method

three physical quantities of the primary atomization characteristics were obtained:the main frequency of the liquid film surface wave

the breakup length and the transversal wave length. The experiment results indicated that: (1) the three liquid film breakup morphologies in the planar prefilming nozzle primary atomization process were divided into end breaking

wave dropping and surface stripping based on the breakup morphology of side view and top view. The effect of inlet Weber number on breakup morphology of the prefilming nozzle was dominant. (2) The combination method of POD analysis and liquid film edge position analysis was applied to the post-processing analysis of the high-frequency non-contact optical image

as an effective data post-processing method. (3) The effect of inlet Weber number played an important role in liquid film breakup morphology. The primary atomization characteristics of the liquid film were mainly affected by the inlet Weber number and the gas-liquid momentum flux ratio. Both the breakup length and the transversal wave length decreased with the increase of the inlet Weber number

the frequency of the liquid film surface wave increased with the increase of the inlet Weber number and the obtained formula is in good agreement with the experiment data. The effect of the inlet parameters on the breakup morphology and atomization characteristics of the liquid film provides a basis for effectively optimizing the atomization quality of the prefilming nozzle.