Delivering pesticide droplets accurately to a target has always been a challenge for crop spraying. Pesticide spray that drifts or runs-off the crop are major sources of soil and groundwater pollution and encourage pesticide overuse. This study optimised an agricultural air-induction nozzle to overcome these difficulties. Various configurations were designed and manufactured to investigate the geometrical parameters. A range of experiments were designed and carried out to simulate field conditions and examine spray structure, stability, droplet size range, and the probability of microbubbles to determine correlations between droplet size and spray drift and droplet rebound potential with or without entrained microbubbles. The performance of the designed nozzle was compared to that of commercial nozzles. Optical diagnostic methods, including high-speed photography, laser diffraction-based droplet sizing, and microscopic flow visualisation, were employed to perform accurate investigations of droplet size range and microbubble presence potential. In addition, the spatial distribution of spray influenced by lateral wind was investigated in an open-type wind tunnel and measured using a 2-dimensional patternator and water-sensitive papers. The rebound potential of the droplets was investigated using high-speed photography for artificial leaves. The results demonstrate the significance of geometrical design factors on the performance of nozzles and the effectiveness of induced air on the reduction of drift and rebound potential. Droplets including microbubbles were found to distribute across the surface of the target leaves on impact and exhibit increased rebound resistance.

将农药液滴准确地输送到目标一直是作物喷洒的挑战。随作物飘散或流失的农药喷洒是土壤和地下水污染的主要来源，并助长了农药的过度使用。本研究优化了农用进气喷嘴以克服这些困难。设计和制造了各种配置以研究几何参数。设计并进行了一系列实验来模拟现场条件并检查喷雾结构、稳定性、液滴尺寸范围和微气泡的概率，以确定液滴尺寸与喷雾漂移和液滴反弹潜力之间的相关性，有或没有夹带微气泡。设计喷嘴的性能与商业喷嘴的性能进行了比较。光学诊断方法，包括高速摄影、基于激光衍射的液滴尺寸和微观流动可视化，被用来对液滴尺寸范围和微气泡存在潜力进行准确研究。此外，在开放式风洞中研究了受侧向风影响的喷雾空间分布，并使用二维图案仪和水敏纸进行了测量。使用人造叶子的高速摄影研究了液滴的回弹潜力。结果证明了几何设计因素对喷嘴性能的重要性以及诱导空气对降低漂移和回弹潜力的有效性。发现包括微泡的液滴在撞击时分布在目标叶片的表面，并表现出增加的回弹阻力。