Circular double arc drift-proof cover design and optimization of drift-proof performance parameters
In order to reduce pesticide application and improve pesticide utilization,a circular double arc drift shield was optimized.The finite element software ANSYS FLUENT was used to simulate the flow field of the annular double arc cover spray,and the velocity vector distribution and discrete phase trajectory of the continuous phase flow field were obtained.Droplet deposition rate was used as a test index,through single factor and multi factor simulation tests,the optimal combination of structural parameters of the cover was obtained as follows:the inlet height of the cover was 48.74 mm,the outlet length was 15.11 mm,and the height from the nozzle to the outlet plane was 32.53 mm;under the optimal combination,the droplet deposition rate was 68.8%.The droplet deposition rates of hooded and conventional hoodless sprays at five wind speeds(1 m/s,2 m/s,3 m/s,4 m/s and 5 m/s)were also compared in a spray table test.The results showed that the droplet deposition rates of cover spray were 80.58%,75.57%,65.16%,59.47%and 54.29%respectively,which were higher than those of conventional spray,which were 72.42%,61.24%,45.1%,38.34%and 32.08%respectively.Covered sprays were more effective than conventional uncovered sprays in preventing drift.The cover spray had better anti drift effect than conventional non cover spray.