孔口尺寸和喷雾压力对典型扇形航空喷头雾化特性的影响研究

Effect of Orifice Size and Spray Pressure on the Atomization Characteristics of Fan-shaped Aerial Nozzles

为探究植保无人机所配套使用的多种典型扇形航空喷头的雾化特性,采用DP-02激光粒度仪分别对延长范围型喷头CFA11001、CFA110015、CFA11002、CFA11003和CFA11004,以及标准扇形喷头SF11002和TeeJet11002进行雾滴粒径测试及相关喷雾数据统计分析,并且就孔口尺寸和喷雾压力对各型号扇形航空喷头雾化特性的影响进行研究。试验结果表明,在固定喷雾压力(0.6MPa)条件下,CFA型喷头随着孔口尺寸的不断增大,雾滴粒径尺寸和粒径分布范围持续增大,其中,D_(V0.1)的极差最小,D_(V0.9)的极差最大。同时,对于具有相同孔口尺寸的3种不同类型喷头,TeeJet11002和SF11002型标准扇形喷头的喷雾性能表现较为稳定,二者的雾滴粒径尺寸和粒径分布范围均较小;CFA11002延长范围型喷头雾滴粒径尺寸则较大,雾滴粒径分级为粗(C),高达259.3μm,雾滴粒径分布也更广,主要集中于110~600μm。在0.2~0.8MPa,TeeJet11002、SF11002和CFA11002的喷头雾滴粒径呈现出随压力增大而变小的趋势。其中,TeeJet11002喷头在整体测试压力范围内表现较为稳定,SF11002喷头次之,而CFA11002喷头由于喷头结构设计的差异,在该压力范围内雾化性能表现出了一定的波动性,D_(V0.1)、D_(V0.5)和D_(V0.9)的极差分别达到4.8,24.8,84.4μm。研究还发现,孔口尺寸和喷雾压力均是影响扇形航空喷头雾滴粒径尺寸和雾滴粒径分布的重要因素,其中相较于标准扇形喷头,喷雾压力对CFA延长范围型喷头影响较大,该类型喷头喷施雾滴粒径尺寸也相对较大,粒径分布范围更广;标准扇形喷头雾滴粒径尺寸则较小,粒径分布更加均匀且稳定。研究结果可为航空喷头的设计与选择提供参考,对优化航空喷洒方案也有一定指导意义。

In order to explore the atomization characteristics of various typical fan-shaped aviation nozzles used in spraying drone,the effects of orifice size and spray pressure on the atomization characteristics of the nozzles were investigated in this study,using the DP-02 spray droplet size analyzer to test the droplet size of the extended-range nozzles and the standard fan-shaped nozzles and carry out the statistical analysis of related spray data.The test results showed that,under the condition of fixed spray pressure(0.6MPa),with the continuous increase of the orifice size of the CFA type nozzle,the size of the droplet and the distribution range of the droplet size increased.Among them,the range of D_(V0.1) was the smallest,and the range of D_(V0.9) was the largest.For three different types of nozzles with the same orifice size,the spray performance of TeeJet11002 and SF11002 standard fan-shaped nozzles were relatively stable,and the droplet size and droplet size distribution of both were small;the CFA11002 extended range type nozzle had a larger droplet size,up to 259.3μm,and it was classified as coarse(C);and the droplet size distribution was also wider,mainly concentrated between 110μm and 600μm.Within the pressure range of 0.2-0.8MPa,the droplet size of the three nozzles,TeeJet11002,SF11002 and CFA11002,showed a decreasing trend with the increase of pressure.Among them,the performance of TeeJet11002 nozzle was relatively stable at all test pressure;followed by the SF11002 nozzle,and the CFA11002 nozzle had a certain fluctuation in the atomization performance within this pressure range due to the different nozzle structure design,the range of D_(V0.1),D_(V0.5) and D_(V0.9) reached 4.8μm,24.8μm and 84.4μm respectively.It was also found that orifice size and spray pressure were both important factors affecting the droplet size and droplet size distribution of fan-shaped aerial nozzles.Compared with standard fan-shaped nozzles,spray pressure had a greater impact on CFA extended-range nozzles,and this type of nozzle had a relatively large droplet size and a wider droplet size distribution;the standard fan-shaped nozzle had a smaller droplet size,and the droplet size distribution was more uniform and stable.The research results can provide reference for the design and selection of aerial nozzles,and the optimization of aviation spraying scheme.