Objective  To study the effect of different viscosities of pesticides on the atomization characteristics of spray nozzles, and provide a theoretical reference for agricultural pesticide spray technology.

Method  Different mass fractions of glycerol solution were configured to replace pesticide reagents for research. The spray area of the spray nozzle was gridded, and the phase Doppler anemometry was used to measure droplet parameters at different positions in the spray area. The statistical law of droplet size in the axial direction and radial direction was analyzed using SPSS.

Result  In the axis direction of the spray area of the nozzle, arithmetic mean diameter, volume mean diameter, and Sauter mean diameter showed the law of first becoming smaller and then gradually increasing. The disturbance of the external air resistance made a certain pattern of surface waves on the surface of the ejected liquid. As the distance increased, the amplitude of the waves became larger, and the wave crests were torn off and broken into small droplets. Then under the action of gravity, the droplets collided and aggregated, and the droplet size gradually increased. In the radial direction of the spray area of the nozzle, the droplets were approximately symmetrically distributed, and the size of the droplets was small in the middle and large on the two sides. With the increase of the radial distance, the size of the droplets gradually increased. SPSS analysis showed that in the axial direction of the spray area the correlation coefficients of axial distance, liquid viscosity with droplet size were 0.531 and 0.795 respectively. In the radial direction the correlation coefficients of radial distance, liquid viscosity with droplet size were 0.932 and 0.328 respectively.

Conclusion  To a certain extent, liquids with greater viscosity have a certain effect of preventing drift. The changes in liquid viscosity have a significant effect on the droplet size in the axial direction. In the axial direction of the nozzle, changes in distance have a significant effect on the droplet size.