# Drift Potential Characteristics of a Flat Fan Nozzle: A Numerical and Experimental Study
## 5 Conclusions  
In this study, the drift potential characteristics of planar fan head nozzles were studied using CFD and wind tunnel tests. The results show that:  
1. The droplet spectrum parameters and droplet drift results correlated with the test and can be obtained through measurement and analysis of the actual spraying process and the establishment of an appropriate spraying model. The statistical results of the data from the simulation of all droplet particle sizes for a short duration compared to the droplet particle sizes on a line tested by a particle-size laser beam were poor. However, the numerical simulation accurately predicted droplet drift.
2. Under different spray conditions, the characteristic height of the droplet drift \(h\), the drift distance, the accurate deposition rate \(R_{h}\), and the horizontal drift rate \(R_{h}\) were directly affected by the lateral wind speed. For the simulation results, the accurate deposition rate of \(R_{a}\) at wind speeds of 1 m/s and 6 m/s were 10.04% and 0.66%, respectively. The horizontal drift rate \(R_{h}\) at wind speeds of 1 m/s and 6 m/s were 21.28% and 60.58%, respectively. According to the test results, the characteristic height \(h\) at wind speeds of 1 m/s and 6 m/s were 0.175 m and 0.245 m, respectively. The horizontal drift rate at wind speeds of 1 and 6 m/s was 0.4% and 75.1%, respectively. For different wind speeds, the correlation between the results of the numerical simulation and wind tunnel test for drift and drift data was more than 0.9.
3. Compared with wind tunnel tests, hydrodynamic modeling and analysis can greatly save computation and experimentation resources by ensuring the correlation of results. Meanwhile, its results can be accurately visualized, and the test result data can be easily analyzed through statistics, reducing post-processing time.  
A 3D virtual spray environment was established using the CFD method to analyze droplet size and deposition drift characteristics and to overcome the uncontrollable factors of an actual spraying environment. The effects of nozzle type, spray pressure, and lateral wind speed on the droplet size and deposition-drift characteristics were preliminarily studied and verified by wind tunnel tests under similar conditions, and it was found that the method was able to predict the droplet drift characteristics according to the nozzle type, spraying pressure, and lateral wind speed. Meanwhile, factors such as spray angle were not considered in the study. The environmental factors of droplet deposition will be introduced in a follow-up study. A comprehensive prediction model of droplet deposition characteristics was established, and its accuracy was improved.  
Investigation, X.Z.; resources, T.Z.; data curation, Q.L.; writing--original draft preparation, J.W.; writing--review and editing, Y.L.; visualization, W.F. All authors have read and agreed to the published version of the manuscript.  
This research was supported by Key Research and Development Projects in Hainan Province (Grant No. ZDYF2020195) and the Academician [PERSON] innovation platform of Hainan Province, Key Research and Development projects in Hainan Province (Grant No. ZDYF2020042), National Natural Science Foundation of China (Grant No. 32160424), Hainan Province Academician Innovation Platform (Grant No. YSPTZX202008), and the Basic and Applied Research Foundation of Guangdong Province (2020A1515110214).  
Not applicable.  
The authors are very grateful to [PERSON] and [PERSON] for their contributions.  
The authors declare no conflict of interest.