Simulation and verification of coupling characteristics of downwash airflow field and droplet field of agricultural unmanned aerial vehicle
Year: 2025
Type: article
Abstract: Background The downwash airflow generated by agricultural UAV rotors significantly affects droplet dispersion, thereby influencing spray performance and increasing the risk of drift. However, the coupled dynamics between rotor-induced airflow and droplet motion remain insufficiently understood. Results In this study, a two-phase CFD model incorporating various rotor speeds was developed and validated through particle image velocimetry (PIV) experiments, achieving fully coupled modeling of the entire pesticide spraying process of agricultural UAV. A functional relationship was established between rotor speed and droplet velocity distribution. The effects of rotor speed on droplet motion—velocity, velocity attenuation rate (K), and spatial distribution—were quantitatively analyzed. Results showed that the maximum droplet velocity occurred near the nozzle, reaching up to 20 m/s. As rotor speed increased, both droplet velocity and concentration increased significantly, while the velocity attenuation rate (K) decreased markedly. Within 1 m below the nozzle, all K values remained below 50 %. PIV measurements agreed well with CFD simulation results, with a minimum relative error of 1 %. Conclusion The integration of CFD and PIV methods provides a reliable framework for studying the interaction between UAV rotor downwash and droplet dynamics. The findings offer theoretical support for optimizing UAV spraying parameters and improving pesticide application efficiency, contributing to enhanced precision in aerial plant protection operations.
Source: Smart Agricultural Technology
Authors: Kun Chang, Shengde Chen, Meimei Wang, Junwei Liu, Ziming Zeng, Yubin Lan
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $1,770
Funders: Scientific and Technological Planning Project of Guangzhou City, Guangdong Polytechnic Normal University, National Key Research and Development Program of China, Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province, Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center)
Awards: G2904264592, G6202911764, G783714373
OpenAlex ID: W7115725857