Effects of structural parameters of the fan nozzle on droplet spatial distribution

In precision agriculture, the droplet spatial distribution of the fan nozzle is a critical determinant of spray efficacy, encompassing effective penetration, coverage, and uniformity. However, unreasonable structural parameters of fan nozzles cause deviations of the droplet spatial distribution from the expected technical requirements. To address the issue, this research investigates the effects of the inner chamber diameter and grooving angle of the fan nozzle on the droplet spatial distribution through a combined approach of numerical simulation and experimental validation. Results show that the grooving angle demonstrates a greater influence on the extension of penetration distance than the inner chamber diameter for equivalent parametric increases. Furthermore, increasing the grooving angle promotes the transition in the droplet coverage shape from elliptical to near circular, whereas the inner chamber diameter has a negligible effect on this shape. An increment in the grooving angle beyond 30° significantly reduces the center-to-edge concentration gradient, enhancing the uniformity of droplet coverage. Overall, the grooving angle not only extends penetration distance but also significantly improves the uniformity of droplet coverage, highlighting its potential for optimizing droplet spatial distribution in precision agriculture.