论文部分内容阅读
Influenced by the complex downwash flow field of the rotors,the movement and deposition of the droplets sprayed by agricultural UAV remained an unclear research domain.Instead of the field experiment,a high speed PIV method was used to measure the movement and deposition of the droplets at different rotating speed of the rotors(1000 RPM to 3000 RPM)or at different transverse injecting points(20cm to 50cm away from the rotors)in the downwash flow field of an agricultural UAV with 8 rotors and conical nozzles.The maximum speed and the size of th e high speed zone of the droplets are found greatly influenced by the downwash velocity.The initial spray angle of the nozzle declines with the increase of downwash flow speed.The downwash velocity was found not only could change the deposition zone of t he droplets,but also influenced their distribution.The increase of the downwash velocity will increase the deposition uniformity of the droplets.The nozzle position in the downwash flow field could also influence the deposition of the droplets.When the distance between the nozzle and the downwash flow is increased,the deposition peak near the downwash flow grows simultaneously.However,the spray angle of the nozzle,and the distance between the deposition peak and the nozzle,stay constant.