Simulation study on the influence of pesticide liquid properties on droplet motion in space

Studying the spatial operation law of pesticide droplets and its influencing factors are of great significance for drift-off, environmental protection and additive development. 2% emamectin benzoate emulsifiable concentrate was selected. The Euler-Lagrange discrete phase model was used to simulate droplet motion in space, and the spatial trajectory of the pesticide droplets was analyzed. The result showed that the atomization process at the outlet of the nozzle was mainly affect by the viscosity and the surface tension of the droplets. The trajectory and drift ratio of the subsequent droplet space operation was determined by the result of the atomization process. With the increase of viscosity and surface tension, the proportion of large particle droplets at the outlet and the average particle size of the droplets increased. While residence time and drift ratio decreased during space operation. Then, the appropriate regulation range of viscosity and surface tension was determined. By increasing the viscosity and surface tension to 0.001-0.01 Pa·s and 0.042-0.060 N/m, respectively, the drift rate became 18.87%-12.67% and 38.93%-24.40%, respectively. According to the actual scene, a specific scheme for regulating the physical properties of the pesticide droplets was proposed. By increasing the viscosity and surface tension of 2% emamectin benzoate emulsifiable concentrate to 0.01 Pa·s and 0.060 N/m, respectively, the drift rate under wind conditions of 4 m/s and 5 m/s can be reduced by 18% and 43%, respectively, which has effectively reduced the drift ratio.