农用荷电喷雾雾滴粒径与速度分布的试验研究

为研究荷电喷雾场的空间运动结构及其对植株界面的影响,该文运用PDPA测试系统对不同条件下的农用静电喷雾场进行了测试,结合荷质比、喷雾宽度测量结果,对雾滴的粒径分布、主流平均速度分布及平均速度与粒径的关系进行了分析和讨论.结果表明:在机械力和电场力的前后作用下,喷嘴压力愈大,荷电雾滴的粒径愈小且分布愈均匀;雾滴的粒径值随充电电压的增加而下降且粒径均匀分散;在较高的充电电压下,单个雾滴动能损耗的降低和雾滴粒径分布的均匀性又促使其主流平均速度分布趋于均匀.在较大粒径时,随着平均速度的增加,非荷电雾滴不易粘附于植株标靶界面;与非荷电相比,小粒径荷电雾滴群又因具有较大动能而提高了抗漂移能力.

Experimental investigation of droplet diameter and velocity distributions in agricultural electrostatic sprays

In order to study the spatial movement structure of electrostatic spray field and its effect on plants interface,the agricultural electrostatic spray field was tested and analyzed in various conditions using PDPA measurement system.According to the test results about the ratio of charge to mass and spray width,the droplet diameter distributions,main average velocity distributions and the relationship between average velocity and droplet diameter were analyzed systematically.The test results indicate that under the influences of mechanical force and electrostatic force,the higher the pressure of the nozzle is,the smaller the electrostatic droplet diameter is.And its distributions are more symmetrical.The droplet diameter reduces and disperses uniform along with the increase of charging voltage.At high voltage,the main average velocity of droplets tends to be uniform because the kinetic energy loss of single droplet decreases and the droplet diameter distribution is uniform.In larger droplet diameter,the uncharged droplets can hardly adhere to plants interface along with the average velocity increment.In comparison with uncharged droplets,the small charged droplets can increase ability against drift because of their larger kinetic energy.