Abstract：In order to explore the influence of various factors on the deposition characteristics of electrostatic spray under the downward washing airflow of a large-load UAV, the Box-Behnken experiment was combined with the orthogonal experiment in this paper. On the basis of qualitative analysis, the mathematical prediction model between deposition characteristic parameters and charged voltage, flight parameters is established. The results showed that the electrostatic spray deposition characteristics of large-load UAV are significantly affected by the charged voltage and flight parameters in the spraying process. The deposition density is positively correlated with the charged voltage, but negatively correlated with flight velocity and flight height. Under the same flight parameters(flight velocity 5 m/s, flight height 4 m), the deposition density of the electrostatic spray under the charged voltage 8kV is 0.318 0 μL/cm2, which is 1.17 times more than that of non-electrostatic spy. At the same time, the deposition density variation coefficient is positively correlated with flight velocity and negatively correlated with charge voltage and flight altitude. It means that the deposition uniformity is improved with the increase of the charged voltage, the decrease of flight velocity or the increase of flight height.
