CFD simulation and experiment of distribution characteristics for droplet of knapsack sprayer

In order to study the droplet distribution characteristics for the knapsack sprayer under different spray conditions, CFD technique (discrete phase particle tracking) was adopted to investigate the droplet distribution of deposition and particle size. In CFD simulations, vertical height from the spray nozzle were 0.4, 0.55 and 0.7 m, spray pressure were 0.15, 0.2, 0.3 and 0.35 MPa and wind speed were 0, 1, 2 and 3 m/s, and the same conditions had been set for knapsack sprayer. The results indicated that wind speed had significant effect on the deposition rate, and it decreased with the increasing of wind speed. The results also showed that wind speed had no significant effect on the pressure. The coefficients of determination and standard error for regression relationship between simulation and experimental results were 0.9424 and 0.039 respectively, which showed that the CFD technique (discrete phase particle tracking) can be used to evaluate deposition distribution, and it should not be used to evaluate particle size distribution because CFD simulation result had a bad correlation with experimental result. This research provides a theory reference for measuring data of sprayers.