Fine-grained method for determining size and velocity distribution patterns of flat-fan nozzle-atomised droplets based on phase doppler interferometer

Pesticides are commonly applied by using agricultural nozzles to generate droplets during delivery process. Initial spray atomization characteristics including droplet size and velocity are important factors that affect the pesticide utilization rate. Exploring efficient methods for atomization measurement is helpful to deeply understanding nozzle sprays. In this study, droplet size and velocity of a flat-fan nozzle were measured with phase doppler interferometry (PDI), and sub-area statistics method was adopted to establish a fitting model for atomization characteristics analyse. The results demonstrated that the distribution patterns and value contrasts of droplet size and velocity in different sub-areas visually reflect the nozzle atomization characteristics under varying spray pressures. The quantized model of droplet size and velocity within spatial sub-areas of spray atomization revealed significant differences in droplet size and velocity at various positions within the atomization area. Near the edge of the initial atomization zone, droplet size increases while velocity exhibits a decreasing trend. Additionally, the coefficient of determination for the x-axis position within the atomization zone, in relation to droplet size and velocity, was above 90%. The PDI with the sub-area statistical method employed in this study offers a fine-grained approach for investigating nozzle atomization characteristics.