Rapid velocity reduction and drift potential assessment of off-nozzle pesticide droplets  

作　　者：Shidong Xue Jingkun Han Xi Xi Junyi Zhao Zhong Lan Rongfu Wen Xuehu Ma 

机构地区：[1]Liaoning Key Laboratory of Clean Utilization of Chemical Resources,Institute of Chemical Engineering,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,China

出　　处：《Chinese Journal of Chemical Engineering》2022年第6期243-254,共12页中国化学工程学报（英文版）

基　　金：This work was financially supported by the National Key Research and Development Program of China(2017YFD0200304).

摘　　要：The droplet velocity and diameter significantly affect both the spatial drift loss and the interfacial deposition behaviors, thus determining the ultimate utilization efficiency during pesticide spraying.Investigating the spatial velocity and diameter evolutions can reveal the mechanism of drift loss and guide to design regulation strategy. Here, we explored the spatial velocity distribution of droplets after leaving the nozzle by particle image velocimetry technology and particle tracking model, considering that the effect of nozzle configuration and the air velocity. It shows that all droplets decelerate rapidly with the velocity attenuation ratio ranging from 50% to 80% within the region of 200 mm below the nozzle.The spatial velocity evolution differences between droplets in crossflow are determined by the competition of vertical drag force and net gravity, and the drag force sharply increases as the droplet diameter decreases, especially for that smaller than 150 μm. Based on the spatial evolution differences of the droplet velocity and diameter, a functional adjuvant was added to the liquid for improving the diameter distribution. And the drift loss was significantly reduced due to the reduction of the proportion of easily drifting droplets.

关 键 词：Spray droplets Particle image velocimetry(PIV) Particle size distribution Multiphase flow Pesticide drift 

分 类 号：S491[农业科学—植物保护]