Downwash airflow field distribution characteristics and their effect on the spray field distribution of the DJI T30 six-rotor plant protection UAV  

作　　者：Haiyan Zhang Sheng Wen Chunling Chen Qi Liu Tongyu Xu Shengde Chen Yubin Lan 

机构地区：[1]College of Information and Electrical Engineering,Shenyang Agricultural University,Shenyang 110866,China [2]College of Engineering,South China Agricultural University,Guangzhou 510642,China [3]College of Agricultural Engineering and Food Science,Shandong University of Technology,Zibo 255022,Shandong,China [4]College of Electronic Engineering(College of Artificial Intelligence),South China Agricultural University,Guangzhou 510642,China [5]National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology,Guangzhou 510642,China

出　　处：《International Journal of Agricultural and Biological Engineering》2023年第2期10-22,共13页国际农业与生物工程学报（英文）

基　　金：financially supported by the 111 Project(Grant No.D18019);Laboratory of Lingnan Modern Agriculture Project(Grant No.NT2021009);the Leading Talents of Guangdong Province Program(Grant No.2016LJ06G689);the National Natural Science Foundation of China(Grant No.32271985);the Natural Science Foundation of Guangdong Province(Grant No.2022A 1515011008;No.2022A1515011535);Liaoning Provincial Education Department Key Research Project(Grant No.LSNZD 202005).

摘　　要：Spray characteristics are the fundamental factors that affect droplet transportation downward,deposition,and drift.The downwash airflow field of the Unmanned Aviation Vehicle(UAV)primarily influences droplet deposition and drift by changing the spray characteristics.This study focused mainly on the effect of the downwash airflow field of the UAV and nozzle position on the droplet spatial distribution and velocity distribution,which are two factors of spray characteristics.To study the abovementioned characteristics,computational fluid dynamics based on the lattice Boltzmann method(LBM)was used to simulate the downwash airflow field of the DJI T30 six-rotor plant protection UAV at different rotor rotational speeds(1000-1800 r/min).A particle image velocimetry system(PIV)was utilized to record the spray field with the downwash airflow field at different rotational speeds of rotors(0-1800 r/min)or different nozzle positions(0,0.20 m,0.35 m,and 0.50 m from the motor).The simulation and experimental results showed that the rotor downwash airflow field exhibited the‘dispersion-shrinkage-redispersion’development rule.In the initial dispersion stage of rotor airflow,there were obvious high-vorticity and low-vorticity regions in the rotor downwash airflow field.Moreover,the low-vorticity region was primarily concentrated below the motor,and the high-vorticity region was mainly focused in the middle area of the rotors.Additionally,the Y-direction airflow velocity fluctuated at 0.4-1.2 m under the rotor.When the rotor airflow developed to 3.2 m below the rotor,the Y-direction airflow velocity showed a slight decrease.Above 3.2 m from the rotor,the Y-direction airflow velocity started to drastically decrease.Therefore,it is recommended that the DJI T30 plant protection UAV should not exceed 3.2 m in flight height during field spraying operations.The rotor downwash airflow field caused the nozzle atomization angle,droplet concentration,and spray field width to decrease while increasing the vortex scale in the spray field

关 键 词：downwash airflow spray field distribution plant protection UAV characteristics 

分 类 号：O35[理学—流体力学]