摘要
3WZF-400A型果园风送喷雾机通过安装直线导流板引导了气流速度场,在一定程度上解决了传统轴流式风送喷雾机农药浪费以及防治效果差的问题,但仍无法使靶标区域的气流速度分布与作物冠层轮廓匹配。本文以计算流体力学为手段,对该型喷雾机进行了改进设计。通过设置不同数量和角度的短导流板进一步引导喷雾机气流场,并建立了对应的气流速度场分布模型。通过对比选取最佳的改进设计方案,并进行了试验验证与喷雾性能测试。研究结果表明,当短导流板数量为2,喷雾机导流板角度组合为45°、15°、-15°和5°,且风机风速为20 m/s时,在靶标处的气流速度分布能够与作物冠形轮廓匹配,所建立的模型能够较准确地模拟喷雾机实际气流速度场的分布。在此基础上以雾滴覆盖率为指标评价了改进设计后的喷雾机喷雾性能,并与改进前的喷雾机喷雾性能作对比,结果表明雾滴能够在垂直平面内按照作物冠形合理分布。
The traditional axial-flow air-assisted orchard sprayer is lack of guidance for air-assisted spraying,which would lead to the waste of pesticide.The 3 WZF-400 A orchard air-assisted sprayer uses two linear guide plates to guide its air-velocity field,which could partly solve the problem,but it still could not make the distribution of air-velocity match the canopy shape at the target.To this matter,the air-velocity field distribution model was established by CFD simulation,and the optimized angle was selected with combination of the two linear guide plates as the basis for the further improvement.Short guide plates with different angles and quantities were set up to subdivide the air-velocity field above.Proper combination of the two linear guide plates could make the airflow concentrate to the canopy range,the optimized angle are 45° for the upper and 5° for the lower.Short guide plates could effectively subdivide the air-velocity field,and could concentrate the airflow to the target.But too many short guide plates would lead to the interference of airflow.The optimized quantities and angels for short guide plates are 2,15° and-15°.The experimental verification and spray performance test were carried out.The maximum relative error between analog value and measured value was 22.87%,which caused by the attenuation of the air-velocity and the instability of the airflow source.The droplet coverage rate was used to evaluate the spray performance of the improved air-assisted sprayer,the comparison experiment between previous sprayer and the improved sprayer showed that the droplets could be reasonably distributed according to the canopy shape in the vertical plane.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2017年第S1期15-21,共7页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家重点研发计划项目(2016YFD0200700)
关键词
喷雾机
风送喷雾
果园
计算流体力学
改进设计
sprayer
air-assisted spraying
orchards
computational fluid dynamics
improved design
