CFD‐based pesticide selection for a nozzle used in a six‐rotor UAV in hover mode for tea spraying

• Published in: Pest management science 2023-05, Vol.79 (5), p.1963-1976
• Main Authors: Dong, Si‐Jia, Gui, Qing‐Hua, Zhu, Lin, Zou, Xiao‐Rui, Zhou, Wen‐Xuan, Hou, Ru‐Yan, Moray, Peter Jusu, Yin, Cheng‐Long
• Format: Article
• Language: English
• Subjects: CFD; Computational fluid dynamics; Computer applications; Crop dusting; Crops; Crops, Agricultural; Downwash; downwash flow structure; Field tests; Fluid dynamics; Fluid flow; Hydrodynamics; Insecticides; Mathematical models; Nozzle design; Numerical models; pesticide selection; Pesticides; Pesticides - analysis; Plantations; Rotors; Saponins; Spraying; Tea; tea plantation; UAV spray; Unmanned Aerial Devices; Unmanned aerial vehicles; Working conditions
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.7371

BACKGROUND A key challenge for unmanned aerial vehicle (UAV) spraying sometimes used in tea plantations is the downwash flow structure there stronger than in crops. In addition, the UAV spray is affected by the relationship between the nozzle design and the pesticide. However, there is little current research on this aspect. As a preliminary step this study focuses on the most appropriate pesticide for a designated nozzle in a six‐rotor UAV according to the nozzle–pesticide relationship using a three‐dimensional computational fluid dynamics model. This model considers the downwash flow structure effect and nozzle spray performance in hover. Nozzle FVP110‐02, widely used in six‐rotor UAVs, is used as a representative nozzle and bifenthrin and tea saponin water, commonly used in tea plantations, are used as the pesticides. RESULTS The downwash flow structure of the six‐rotor UAV in hover was conveniently controlled by the flight height and rotational speed, thereby causing the turbulence to be more stable. For nozzle FVP110‐02, bifenthrin was more appropriate than tea saponin water at the same concentration, whilst bifenthrin and tea saponin water at a concentration of 1:1000 showed the best performance under identical working conditions. CONCLUSION The numerical model developed here was shown to be effective for investigating the relationship between nozzle and pesticide. Our findings will help to not only improve UAV spraying for tea cultivation but also provide guidelines for pesticide selection in crops. Further work will address the comparison of the rigorous qualification of the numerical simulations with the measurements by the field test. © 2023 Society of Chemical Industry. The most appropriate pesticide for a designated nozzle of a six‐rotor unmanned aerial vehicle for tea cultivation was numerically determined according to the nozzle–pesticide relationship using a three‐dimensional computational fluid dynamics model.