Establishing reference nozzles for classification of aerial application spray technologies

Fritz, Bradley K.; Hoffmann, W. Clint

doi:10.33440/j.ijpaa.20180101.0003

Cited by 4 publications

(6 citation statements)

References 6 publications

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“…It can also be found that the effect of spray pressure on the droplets size of nozzle 11010 was not obvious, which with the largest orifice size, only DV0.1 and DV0.5 met this trend under low-speed airflow conditions of 0 m/s ( Figure 8a), 16.7 m/s (Figure 8b Figure 8 Droplet size test results for each type of nozzle under three spray pressure SV, V<100 (%volume) and RS for each nozzle within each classification category for each measurement airflow velocity (Table 3-8) are given below. By counting the values of spray parameters at each airflow velocity, it can be found that 89% of the SV was in the range of less than 15%, which was similar to the results of Womac [31] and Fritz's [26] research. This indicated that in most cases the spraying performance of each type of nozzle was relatively stable.…”

Section: Effect Of Spray Pressure On Spray Parameters Of Various Nozzlessupporting

confidence: 85%

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Atomization characteristics of multi-type aerial nozzles in wind tunnel and low airflow velocity condition in manned agricultural helicopter

Yao

Lan²,

Hoffmann³

et al. 2019

International Journal of Precision Agricultural Aviation

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In order to explore the atomization characteristics of the LICHENG series nozzle for manned agricultural helicopter under medium and low airflow velocity conditions, droplet size tests on five sizes of nozzles 11002, 11003, 11004, 11006 and 11010 were carried out by laser diffraction device (LDD), based on the high-low speed composite wind tunnel for agricultural aviation designed by the National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology (NPAAC) of South China Agricultural University (SCAU). The results showed that under the three spray pressures of 30, 40 and 50 psi, the droplet sizes of the five types of nozzles expressed similar trends with the increase of airflow velocity. Among them, the droplet size variation of nozzles 11006 and 11010 with larger orifice size was the most significant, the largest range of DV0.1 was nozzle 11010, and the largest range of DV0.5 and DV0.9 was nozzle 11006. In addition, the changes of spray pressure would directly affect the quality of spray, especially the nozzles 11002, 11003 and 11004 with small orifice sizes were significantly affected. Under the condition of medium and low airflow velocity of 0-27.8 m/s, 89% of spread value (SV) by the five nozzles were in the range of less than 15%, but there were some test nozzles with poor spray stability during the test, which made the measurements of droplet size value larger, resulting in a maximum test deviation of up to 210.9 μm. The result also exposed the limitations exist in wind tunnel droplet size testing by using LDD, and an increase in airflow velocity resulted in a larger measurement droplet size. This phenomenon was particularly significant in the DV0.5 test results of various types of nozzles. This study can provide experimental data guidance for the optimization design and parameter selection of aerial nozzle for manned agricultural helicopter.

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Section: Effect Of Spray Pressure On Spray Parameters Of Various Nozzlessupporting

confidence: 85%

“…The parameters evaluating the atomization performance of the nozzle are DV0.1, DV0.5, DV0.9, V<100 (%volume), relative span (RS), and spread value (SV) [26]. The DVa values are the droplet diameters (µm) where (a × 100) % of the spray volume is accumulated in droplets with diameters smaller than this value.…”

Section: Evaluation Parametermentioning

confidence: 99%

Atomization characteristics of multi-type aerial nozzles in wind tunnel and low airflow velocity condition in manned agricultural helicopter

Yao

Lan²,

Hoffmann³

et al. 2019

International Journal of Precision Agricultural Aviation

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“…Thus, in terms of agricultural aviation, China lags far behind the United States, Russia, Australia, Canada, Brazil, Japan, and South Korea. In the sparsely populated areas of the United States, manned fixed-wing aircraft is the most popular form of agricultural aviation [4][5][6][7] . The development mode of agricultural aviation in Russia, Australia, Canada, and Brazil is the same as that in the United States, which is characterized by the use of manned fixed-wing aircraft and rotary-wing helicopters [8] .…”

Section: Introduction mentioning

confidence: 99%

Effects of plant protection UAV-based spraying on the vertical distribution of droplet deposition on Japonica rice plants in Northeast China

Cao

et al. 2021

International Journal of Agricultural and Biological Engineering

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In order to study the regularity of the vertical distribution of droplet deposition on rice plants during pesticide spraying operated by a low-flying multi-rotor plant protection unmanned aviation vehicle (UAV), water-sensitive spray cards were placed on the leaves at the top, in the middle, and at the bottom of rice plants to acquire data on droplet deposition. In this study, a suspension containing tricylazole and hexaconazole was used in the spraying. The water-sensitive spray cards were analyzed by the droplet deposition processing software iDAS to obtain the vertical distribution of the droplets sprayed by the plant protection UAV. The results showed that 1) significant variation was found in the coverage of the droplets in different vertical positions of the rice plants. Within the effective spray width, the best coverage of the droplets was found in the area just below the rotors, whereas the coverage of areas farther away from the rotors was poor. For the different vertical positions of the rice plants, the overall droplet coverage was 58.38% at the top, 33.55% in the middle, and 11.34% at the bottom of the plants; 2) for all vertical positions, the average size of the droplets ranged between 110 μm and 140 μm, which was suitable for the control of plant diseases and insect pests. The highest droplet density was found at the top of the plants, and the distribution of the droplet density was similar in the middle and at the bottom of the rice plants; 3) the diffusion ratio at the top of the rice plants (0.84) was better than that in the middle (0.57) and at the bottom (0.37). The overall relative span could meet the requirements for the actual application. Except for the position in the middle of the plants, the relative span for the other positions of the plants was over 0.67, which is the standard value. This study demonstrated the distribution regularity of droplet deposition along with the vertical direction of rice plants during UAV-based spraying, which is of guiding significance for the use of UAVs in plant protection, the improvement of chemical utilization efficiency, and the reduction of pesticide and fertilizer pollution.

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“…The room temperature and air humidity were kept constant during the test, and the test reagent was water. Each test was repeated at least three times with a test time of 30 seconds to ensure that the standard deviation of the droplet size data of the same group was not greater than 10% [5].…”

Section: Spray Test Design Of Wind Tunnelmentioning

confidence: 99%

“…Nozzle is the most critical component in aviation application equipment, and it will directly affect control effect of the application. Droplet size is an indicator of atomization performance, which is also a reference for nozzle design and selection [4,5]. Related studies have shown that if the droplet size is too large or too small, it will cause problems such as waste loss or drift and phytotoxicity.…”

Section: Introductionmentioning

confidence: 99%

Droplet Size Distribution Characteristics of Aerial Nozzles by Bell206L4 Helicopter under Medium and Low Airflow Velocity Wind Tunnel Conditions and Field Verification Test

Yao

Lan

Hoffmann³

et al. 2020

Applied Sciences

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To investigate the spray atomization characteristics of aerial nozzles adapted to manned agricultural helicopters under medium-low airflow velocity (0 to 27.8 m/s) conditions, the droplet size test was carried out in both wind tunnel and field tests. In the wind tunnel test, the laser diffraction device (LDD) was used to test the spray droplet size of CP02, CP03, and CP04 aerial nozzles. A Bell206L4 helicopter was used in the field test. The results in the wind tunnel test showed that due to the nozzles had been used for a long time and the cause of wear, the spray stability of individual nozzles was affected during the test. The limitation of droplet size measurement by using LDD was also found. The field test results showed that the main distribution range of the droplet size measured in the field test was consistent with the results of the wind tunnel test, but the droplet size value was significantly higher and the uniformity of droplet size distribution was poorer than the wind tunnel test value due to the influence of the actual environment. However, the results of field test and wind tunnel test can still be used as a reference for each other.

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Establishing reference nozzles for classification of aerial application spray technologies

Cited by 4 publications

References 6 publications

Atomization characteristics of multi-type aerial nozzles in wind tunnel and low airflow velocity condition in manned agricultural helicopter

Atomization characteristics of multi-type aerial nozzles in wind tunnel and low airflow velocity condition in manned agricultural helicopter

Effects of plant protection UAV-based spraying on the vertical distribution of droplet deposition on Japonica rice plants in Northeast China

Droplet Size Distribution Characteristics of Aerial Nozzles by Bell206L4 Helicopter under Medium and Low Airflow Velocity Wind Tunnel Conditions and Field Verification Test

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