Numerical Analysis and Wind Tunnel Validation of Droplet Distribution in the Wake of an Unmanned Aerial Spraying System in Forward Flight

Ruiz, Manuel Carreño; Bloise, Nicoletta; Guglieri, Giorgio; D’Ambrosio, Domenic

doi:10.3390/drones6110329

Cited by 12 publications

(14 citation statements)

References 35 publications

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“…Hollow cone nozzles, such as the MGA015, are characterized by a greater deposition of liquid on the outside of the cone, since there are practically no droplets in the center, and are widely used for applications in fruit trees. During the applications in a wind tunnel using UAV that greater turbulence in the distribution of drops was generated, due to the swirl chamber present in the hollow cone nozzles [49]. Thus, during the applications on papaya plants, a better droplet distribution was observed along the canopy and on the papaya fruit clusters.…”

Section: Discussionmentioning

confidence: 99%

Impact of Operational Parameters on Droplet Distribution Using an Unmanned Aerial Vehicle in a Papaya Orchard

et al. 2023

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Papaya production and export is increasingly expanding in the world market due to the nutritional importance of the fruit. Phytosanitary issues, labor shortages, and unevenness in land-based costal and motorized applications compromise crops, the environment, and humankind. The purpose of this study was to evaluate the efficiency of droplet distribution using an unmanned aerial vehicle, with different application rates (12.0, 15.0, and 18.0 L ha−1) and spray nozzles (XR110015 and MGA015) in the upper (UL), middle (ML), and lower (LL) layers, and on papaya fruit clusters (BF). Water-sensitive paper labels and artificial targets were used to assess the efficiency. Coverage, density, droplet distribution, and droplet diameter were influenced by the application rates in the following order: 18.0 > 15.0 > 12.0 L ha−1, showing concentrated droplet distribution in the respective layers: UL > ML > LL > BF. The 18.0 L ha−1 rate increased the variables examined, and the droplet coverage on the UL using the XR110015 nozzle was 6.56 times greater than that found on the LL and BF. The MGA015 nozzle presented better results in the LL and BF in all variables analyzed. The UAVs were efficient in applying to the papaya crop and further studies should be carried out in order to confirm the efficacy of plant protection products applied using this technology.

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Section: Discussionmentioning

confidence: 99%

Impact of Operational Parameters on Droplet Distribution Using an Unmanned Aerial Vehicle in a Papaya Orchard

et al. 2023

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“…The interaction between spray and rotors has been experimentally tested both in the open field [12] and in wind tunnel facilities [13][14][15], where the authors investigate drift with varying wind speed, spray volume, and nozzle characteristics. Drift is also addressed in [16], where the authors survey solutions to reduce the inevitable drift by optimizing the rotor, nozzle setup, spray system, and flight parameters.…”

Section: Introductionmentioning

confidence: 99%

“…The previous computational works were performed using a volume-of-fluid (VOF) approach. With an adequate estimation of the input parameters, the Lagrangian model can model the spray drift and is becoming popular in computational approaches such as in [14,24,25], which present qualitative and quantitative validation studies. Apart from validation studies, Chen [25] also presents an optimization based on Radial Basis Functions (RBF) to explore optimal nozzle positioning.…”

Section: Introductionmentioning

confidence: 99%

Toward Virtual Testing of Unmanned Aerial Spraying Systems Operating in Vineyards

Carreño Ruiz,

Bloise,

Guglieri

et al. 2024

Drones

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In recent times, the objective of reducing the environmental impact of the agricultural industry has led to the mechanization of the sector. One of the consequences of this is the everyday increasing use of Unmanned Aerial Systems (UAS) for different tasks in agriculture, such as spraying operations, mapping, or diagnostics, among others. Aerial spraying presents an inherent problem associated with the drift of small droplets caused by their entrainment in vortical structures such as tip vortices produced at the tip of rotors and wings. This problem is aggravated by other dynamic physical phenomena associated with the actual spray operation, such as liquid sloshing in the tank, GPS inaccuracies, wind gusts, and autopilot corrections, among others. This work focuses on analyzing the impact of nozzle position and liquid sloshing on droplet deposition through numerical modeling. To achieve this, the paper presents a novel six degrees of freedom numerical model of a DJI Matrice 600 equipped with a spray system. The spray is modeled using Lagrangian particles and the liquid sloshing is modeled with an interface-capturing method known as Volume of Fluid (VOF) approach. The model is tested in a spraying operation at a constant velocity of 2 m/s in a virtual vineyard. The maneuver is achieved using a PID controller that drives the angular rates of the rotors. This spraying mission simulator was used to obtain insights into optimal nozzle selection and positioning by quantifying the amount of droplet deposition.

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“…In addition, some studies conducted computational fluid dynamics (CFD) to obtain the flow field and distribution of downwash, 14,15 to demonstrate the ground effect of spatiotemporal distribution 16 and to investigate the influence of rotors on droplets, deposition and drift. 17 For crosswind, the research approaches are similar. Scholars have mainly concentrated on developing sensors, droplet collectors and CFD models to deeply examine the influence of crosswind on droplet drift.…”

Section: Introductionmentioning

confidence: 99%

“…In terms of downwash, wind speed sensors, 10 cameras 11,12 and water‐sensitive papers 13 are generally used to record downwash velocities, droplet trajectories, high‐speed particle images, droplet deposition and penetration. In addition, some studies conducted computational fluid dynamics (CFD) to obtain the flow field and distribution of downwash, 14,15 to demonstrate the ground effect of spatiotemporal distribution 16 and to investigate the influence of rotors on droplets, deposition and drift 17 . For crosswind, the research approaches are similar.…”

Section: Introductionmentioning

confidence: 99%

Back pressure generated by downwash and crosswind on spatial atomization characteristics during UAV spraying: CFD analysis and verification

Feng,

Xu,

Yang

et al. 2023

Pest Management Science

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BackgroundDuring unmanned aerial vehicles (UAVs) spraying, downwash and crosswind generate back pressure in comprehensive, which changes in spatial atomization characteristics of spraying droplets. However, the process of such atomization characteristics needs to be clarified. This study focuses on the effect of rotor speed and crosswind speed on spatial atomization characteristics. The computational fluid dynamics (CFD) models of the distributions of airflow, back pressure and atomization characteristics were established, and verification was conducted by developing a validation platform.ResultsThe CFD results indicated that small droplets of 65 μm to 130 μm atomized by negative pressure would be coalesced near the nozzle, while large droplets of 390 μm to 520 μm atomized by positive pressure would be aggregated further away. Crosswind caused atomization stratification with droplet sizes of about 90 μm, about 320 μm and about 390 μm. When crosswind speed increased from 3 m/s to 6 m/s, the spraying drifted from 0.5 m to 1 m. When rotor speed increased from 2000 RPM to 3000 RPM, droplet distribution was expanded and droplet particle size was more uniform. Verification results demonstrated that the spraying distribution and the droplet size variation were consistent with the CFD.ConclusionsSpatial atomization characteristics were highly correlated with airflow and back pressure. Moreover, as crosswind generated droplet drift and atomization stratification and downwash could improve the uniformity of droplet distribution, spraying performance was superior by enhancing downwash to restrain the adverse effect of crosswind in the real application.This article is protected by copyright. All rights reserved.

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Numerical Analysis and Wind Tunnel Validation of Droplet Distribution in the Wake of an Unmanned Aerial Spraying System in Forward Flight

Cited by 12 publications

References 35 publications

Impact of Operational Parameters on Droplet Distribution Using an Unmanned Aerial Vehicle in a Papaya Orchard

Impact of Operational Parameters on Droplet Distribution Using an Unmanned Aerial Vehicle in a Papaya Orchard

Toward Virtual Testing of Unmanned Aerial Spraying Systems Operating in Vineyards

Back pressure generated by downwash and crosswind on spatial atomization characteristics during UAV spraying: CFD analysis and verification

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