Design of Narrow-arc Fan-shaped Anti-drift Nozzle Based on Entrainment Effect of Fruit Tree Canopy of UAV

Aiming at the problem of liquid drift caused by plant protection UAV spraying fruit tree canopy, a narrow arc fan nozzle structure is designed by combining the entrainment effect and fan nozzle atomization principle when plant protection UAV sprays fruit tree canopy, through the simulation analysis of the spraying process under different canopy pressure coefficients, the structural parameters of the narrow-arc fan-shaped nozzle with the best anti-drift were obtained. The results show that as the inner diameter of the nozzle increases, the structure of the liquid film and liquid belt tends to be stable, the distribution of droplets is uniform, and the deposition rate first decreases and then increases; the canopy pressure loss coefficient decreases, and the width of the particle size spectrum decreases, but the overall deposition rate improvement.For thick canopy fruit tree planting, choose a nozzle with an inner diameter of 1.30 mm and a slit width of 0.15 mm, with a particle size spectrum width of 0.706 and a deposition rate of 95.2%.For plant protection of thin canopy fruit trees, choose an inner diameter of 1.03 mm and a slit width of 0.20 mm, the nozzle has a particle size spectrum width of 0.858 and a deposition rate of 98.2%. The droplet spectrum of the narrow-arc fan-shaped nozzle is greater than 0.7, and the deposition rate is greater than 94.1%.