@misc{oai:niigata-u.repo.nii.ac.jp:00005482,
 author = {Bai, Geng},
 month = {Mar},
 note = {5.1. Characteristics and classification of Japanese nozzles based on relative spray drift potential In conclusion, the relative drift potential for one series of drift reduction nozzles used in Japan was measured under different combinations of nozzle size, pressure and height. The results reveal that the influence of nozzle height and nozzle size on the index value were statistically significant (**P < 0.01), whereas the nozzle pressure has a significant effect (**P < 0.01) on the index value only for nozzle sizes of 05 and 07. Compared with the reference spray, the ES series nozzles had drift reduction abilities above 50% when the nozzle height was between 0.3 and 0.5 m, except for the ES 05 nozzle. According to the spray distribution performance, the best nozzle height range is between 0.3m and 0.4m above the crop canopy. The results provided the users objective information for the relative drift reduction performance of ES nozzles and could also be expanded as more types of drift reduction nozzles become available., 5.2. The influence of nozzle parameters on the droplet size characteristics, spray angle, liquid flow rate and included air within droplers for the high pressure air inclusion nozzle used in Japan In conclusion, the influence of the key nozzle design parameters for high-pressure air inclusion nozzles, which includes pre-orifice diameter and nozzle tip area on the droplet size characteristics, spray angle, included air within droplet and liquid flow rate were investigated under different nozzle pressures. The combinations of 7 pre-orifice diameters, 6 nozzle tip areas and 3 nozzle pressures, were tested in the pre-test and 93 stable spray conditions were chosen to carry out the measurement of droplet size characteristics, spray angle and liquid flow rate. The correlation analysis among important droplet size characteristics were carried out. The result shows that 77 most of the characteristics had relative high average values which mean they could be used to represent other characteristics. Therefore, Dv0.5 was used to carry out the regression analysis between key design parameters and the droplet size characteristics under different nozzle pressures. The result of the multivariate regression analysis between the key nozzle design parameters and Dv0.5 under different nozzle pressures shows that nozzle tip area, pre-orifice diameter and nozzle pressure were found to have significantly effect on the Dv0.5 (P<0.05) with a coefficient of determination (R2) of 0.81. The positive proportion relation between the nozzle tip area and the Dv0.5 was found. In addition, pre-orifice diameter was negative proportional with the Dv0.5 and this trend was not reported in the previous study. The further investigation should be carried out to explain the result. In addition, nozzle pressure was found to be negative proportional to the Dv0.5 due to the more sufficient atomization under higher nozzle pressure. The results of the multivariate regression analysis between the key nozzle design parameters and spray angle under different nozzle pressures shows that the influence of nozzle pressure and pre-orifice diameter on the spray angle were significant while the effect of nozzle tip area was not (P<0.05). In addition, pre-orifice diameter and nozzle pressure were found to be positive proportional to the spray angle. The result shows that the nozzle pressure and pre-orifice diameter controlled the liquid flow rate with a R2 value of 0.98. From 22 investigated sprays, the regression equation between the key nozzle design parameters and the spray liquid density was obtained. The pre-orifice diameter and nozzle tip area significantly affect the spray liquid density. The influence of the pre-orifice diameter and nozzle tip on droplet size characteristics might be the main reason why the two design parameters significantly influence the spray liquid density., 5.3. The influence of the air inlet design on the spray performance of the air inclusion nozzle used in Japan To get a better understanding of the role air inlet design plays in the air inclusion nozzle, the influence of the air inlet design on the included air within droplets, droplet size characteristics, liquid flow rate, spray angle, deposit weight of spray liquid and coverage rate of the KIRINASHI ES series air inclusion nozzle was carried out. The result showed that the quantity of the included air within droplets was significantly different between the unsealed and sealed group. In addition, the sealing of the air inlet significantly decreased the quantity of the included air within droplets under the investigated conditions. Besides, the included air quantity of KIRINASHI ES series nozzles was slightly higher, comparing with that of low pressure air inclusion nozzles based on previous research. No significant difference of Dv0.5 was found between the results of the two groups. The existence of the air inlet led to a more uniform droplet size distribution based on its influence on the RSF and might lead to better drift control due to a less volume proportion of small droplets. In addition, the sealing of air inlet slightly increased the liquid flow rate but not significantly. For the spray angle, no significant difference of the spray angle was found between the two groups. Although the manufacture claims that the spray angle is 100°, the range of the spray angle varies under different nozzle number and pressure combinations. For the deposit weight of spray liquid, no significant difference were found between the two groups. However, the deposit weight of sealed group was slight higher than that of unsealed group when the nozzle number increased. The test of the coverage rate of the two groups showed that no significant difference was found between the two groups. However, based on the results of the D50 and D100, it could be concluded that the unsealed group might have the potential to decrease the volume proportion of small droplets and have a better drift control while keeping the coverage rate as same as the sealed group., 学位の種類: 博士（農学）. 報告番号: 甲第3937号. 学位記番号: 新大院博（農）甲第140号. 学位授与年月日: 平成26年3月24日, 新大院博（農）甲第140号},
 title = {Spray Performance of the High Pressure Air Inclusion Nozzle Used in Japan : In the aspects of the relative spray drift and the influence of key design parameters on spray performance},
 year = {2014}
}