Performance characterization on downwash flow and spray drift of multirotor unmanned agricultural aircraft system based on CFD

Hongze Li, Hang Zhu, Zihao Jiang, Yubin Lan

Abstract


In recent years, multi-rotor Unmanned Aerial Vehicles (UAVs) have been employed in the field of plant protection in China. Spray drift has been considered a major impact in agriculture aerial spraying, and spray quality in the application of plant protection products. The downwash including wake vortices and downward wind field plays a major role in the dispersal and deposition of pesticide spray released by nozzle(s) equipped in aircraft. Differ from the fixed-wing UAV, the downwash flow of multi-rotor UAV resulted from the rotation of the rotor. Therefore, a study on off-target drift and ground deposit concerning the rotor rotation was simulated through a series of Computational Fluid Dynamics (CFD) simulations to obtain the influence of downwash. The discrete Phase Model (DPM) was taken to simulate the motion of droplet particles since it is an appropriate way to simulate discrete phases in the flow field and can track particle trajectory. In this study, the parameters of CFD simulations were acquired by three kinds of actual replicated experiments. The simulation analysis mainly obtains the droplet drift and deposition rule, the influence of eddy current, and downwash flow caused by the rotor rotation. The results showed that the downwash distribution below different rotors was different owing to the flight angle of inclination, “behind” is the greatest, “middle” is secondly, and “forward” is the smallest in value(behind, middle, and forward represent three regions below rotors along flight direction). According to the simulation results, two methods of reducing droplet drift were put forward and specific simulations were carried out to prove their feasibility. The results of this study can provide theoretical support for improving the spray quality of UAVs and reducing the drift of droplets.
Keywords: Unmanned Aerial Vehicles, spray drift, downward wind field, rotor rotation, eddy current, downwash distribution
DOI: 10.25165/j.ijabe.20221503.7315

Citation: Li H Z, Zhu H, Jiang Z H, Lan Y B. Performance characterization on downwash flow and spray drift of multirotor unmanned agricultural aircraft system based on CFD. Int J Agric & Biol Eng, 2022; 15(3): 1–8.

Keywords


Unmanned Aerial Vehicles, spray drift, downward wind field, rotor rotation, eddy current, downwash distribution

Full Text:

PDF

References


Zhang C, Kovacs J M. The application of small unmanned aerial systems for precision agriculture: A review. Precision Agriculture, 2012; 13: 693–712.

Zhang N, Wang M, Wang N. Precision agriculture - A worldwide overview. Computers and Electronics in Agriculture, 2002; 36(2–3): 113–132.

Kirk I W, Fritz B K, Hoffmann W C. Aerial methods for increasing spray deposits on wheat heads. 2004 ASAE Annual Meeting, 2004; Paper No. 041029. doi: 10.13031/2013.16132.

Fritz B K. Role of atmospheric stability in drift and deposition of aerially applied sprays - Preliminary results. 2004 ASAE Annual Meeting, Paper No. 041031. doi: 10.13031/2013.16143.

Bilanin A J, Teske M E, Barry J W, Ekblad R B. AGDISP: The aircraft spray dispersion model, code development and experimental validation. Transactions of the ASAE, 1989; 32(1): 327–334.

Teske M E. An introduction to aerial spray modeling with FSCBG. Forest Service Cramer-Barry-Grim. Journal of the American Mosquito Control Association, 1996; 12: 353–358.

Hewitt A J. Spray drift: Impact of requirements to protect the environment. Crop Protection, 2000; 19(8–10): 623–627.

Hewitt A J, Johnson D R, Fish J D, Hermansky C G, Valcore D L. Development of the spray drift task force database for aerial applications. Environmental Toxicology and Chemistry, 2002; 21(3): 648–658.

Teske M E, Bird S L, Esterly D M, Curbishley T B, Ray S L, Perry S G.

AgDRIFT®: A model for estimating near-field spray drift from aerial applications. Environmental Toxicology and Chemistry, 2002; 21(3): 659–671.

Teske M E, Thistle H W, Riley C M, Hewitt A J. Initial laboratory measurements of the evaporation rate of droplets inside a spray cloud. Transactions of the ASABE, 2016; 59(2): 487–493.

Fesal S N M, Fawzi M, Omar Z. A numerical analysis of flat fan aerial crop spray. IOP Conference Series: Materials Science and Engineering, 2017; 243: 012044. doi: 10.1088/1757-899X/243/1/012044.

Wilson C, Tisdell C. Why farmers continue to use pesticides despite environmental, health and sustainability costs. Ecological Economics, 2001; 39(3): 449–462.

Xue X Y, Lan Y B, Sun Z, Chang C, Hoffmann W C. Develop an unmanned aerial vehicle based automatic aerial spraying system. Computers and Electronics in Agriculture, 2016; 128: 58–66.

Jiao L Z, Dong D M, Feng H K, Zhao X D, Chen L P. Monitoring spray drift in aerial spray application based on infrared thermal imaging technology. Computers and Electronics in Agriculture, 2016; 121: 135–140.

Li J Y, Shi Y Y, Lan Y B, Guo S. Vertical distribution and vortex structure of rotor wind field under the influence of rice canopy. Computers and Electronics in Agriculture, 2019; 159: 140–146.

Guo S, Li J Y, Yao W X, Zhan Y L, Li Y F, Shi Y Y. Distribution characteristics on droplet deposition of wind field vortex formed by multi-rotor UAV. PLoS One, 2019; 14(7): e0220024. doi: 10.1371/ journal.pone.0220024.

Dorr G J, Forster W A, Mayo L C, McCue S W, Kempthorne D M, Hanan J, et al. Spray retention on whole plants: Modelling, simulations and experiments. Crop Protection, 2016; 88: 118–130.

Ellis M C B, Miller P C H. The Silsoe spray drift model : A model of spray drift for the assessment of non-target exposures to pesticides. Biosystems Engineering, 2010; 107(3): 169–177.

Wen S, Han J, Ning Z H, Lan Y B, Yin X C, Zhang J T, et al. Numerical analysis and validation of spray distributions disturbed by quad-rotor drone wake at different flight speeds. Computers and Electronics in Agriculture, 2019; 166: 105036. doi: 10.1016/j.compag.2019.105036.

Ryan S D, Gerber A G, Holloway A G L. A time-dependent Eulerian model of droplet diffusion in turbulent flow. Computers and Fluids, 2016; 131: 1–15.

Zhang B, Tang Q, Chen L P, Xu M. Numerical simulation of wake vortices of crop spraying aircraft close to the ground. Biosystems Engineering, 2016; 145: 52–64.

Yang F B, Xue X Y, Cai C, Sun Z, Zhou Q Q. Numerical simulation and analysis on spray drift movement of multirotor plant protection unmanned aerial vehicle. Energies, 2019; 11(9): 2399. doi: 10.3390/en11092399.

Omar Z, Qiang K Y, Mohd S, Rosly N. CFD simulation of aerial crop spraying, In: IOP Conference Series: Materials Science and Engineering, 2016; 160: 012028. doi: 10.1088/1757-899X/160/1/012028.

Zhu H, Li H Z, Zhang C, Li J X, Zhang H H. Performance characterization of the UAV chemical application based on CFD simulation. Agronomy, 2019; 9(6): 308. doi: 10.3390/agronomy9060308.

Li L, Qi H, Yin Z, Li D, Zhu Z, Tangwarodomnukun V, et al. Investigation on the multiphase sink vortex Ekman pumping effects by CFD-DEM coupling method. Powder Technology, 2019; 360: 462–480.

Vahabzadeh M, Hossein M, Hong K, Xiong Q. CFD study of heat transfer and fl uid fl ow in a parabolic trough solar receiver with internal annular porous structure and synthetic oil-Al2O3 nanofluid. Renewable Energy, 2020; 145: 2598–2614.

Li Y S, Tian Y, Tian J D, Zhou F. An efficient method for DPM code localization based on depthwise separable convolution. IEEE Access, 2019; 7: 42014–42023.

Zhang L, Ji R Q, Fu Y F, Qi H, Kong F Z, Li H N. Investigation on particle motions and resultant impact erosion on quartz crystals by the micro-particle laden waterjet and airjet. Powder Technology, 2019; 360: 452–461.

Duraisamy K, Iaccarino G, Xiao H. Turbulence modeling in the age of data. Annual Review of Fluid Mechanics, 2019; 51: 357–377.

Mei J, Ren W, Ma G F. Distributed coordinated tracking with a dynamic leader for multiple Euler-Lagrange systems. IEEE Transactions on Automatic Control, 2011; 56: 1415–1421.




Copyright (c) 2022 International Journal of Agricultural and Biological Engineering

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

2023-2026 Copyright IJABE Editing and Publishing Office