Numerical simulation of wake vortices of crop spraying aircraft close to the ground

Zhang, Bin; Tang, Qing; Chen, Liping; Xu, Min

doi:10.1016/j.biosystemseng.2016.02.014

Cited by 33 publications

(13 citation statements)

References 11 publications

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“…Although this kind of fixed-wing airflow does not belong to downwash, ground-effect and droplet distribution were analysed based on it, which is very close to the approach of downwash examination. One published work by Zhang from Northwestern Polytechnical University in China and Tang from National Research Centre of Intelligent Equipment for Agriculture investigated the distribution of wake vortexes of a monoplane, Thrush 510G, identifying that the starboard vortex existed longer than the port one [61] . Ultrasonic anemometers were employed to acquire the airflow velocity during the aircraft passing by.…”

Section: Examination By Using Cfdmentioning

confidence: 99%

Research status and trends of downwash airflow of spray UAVs in agriculture

Yang

Zheng

Liu

2019

International Journal of Precision Agricultural Aviation

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Downwash airflow of spray UAVs in agriculture has been gradually focused on and a few studies have already been involved in it. Thus, this paper firstly reviewed the current research of downwash airflow of UAVs for agricultural spray. It is found that Chinese scholars have published the majority of the studies in this area. Furthermore, two aspects of this kind of research, one, the work related to the caused results of UAV downwash acting on spray, the other, that regarding downwash itself for investigation, were analysed. It is illustrated that the present research usually uses water-sensitive paper, electronic devices, like wind-speed arrays and PIV, and CFD simulation. However, the existed electronic devices have some limitations, such as lacking of the ability of showing and demonstration of downwash in big enough areas in detail during recording. Moreover, the studies directly related to downwash have been just launched around the world and the examination for multi-rotor UAVs is even seriously not enough. Therefore, in terms of research trends, it is significant to develop specialised sensors for downwash measurement. The general and reliable CFD models of a class of UAVs are also needed. In addition, the combination of UAV downwash with real applications and actual production is important for the clarification of the details in different situations.

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Section: Examination By Using Cfdmentioning

confidence: 99%

Research status and trends of downwash airflow of spray UAVs in agriculture

Yang

Zheng

Liu

2019

International Journal of Precision Agricultural Aviation

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“…From Figure 6, the high mass concentration were located at 50 m to 100 m at the central of the plume and reduced as the droplets transported downstream positions at 250 m as the droplets dispersed outwards. Results showed that for a released height of 4.7 meter, the particle mass concentration had the lowest concentration which is 39% reduced from 0.1963 g/m 3 compare to 0.2743 g/m 3 for a released height of 3.7 m.These findings showed the same result explained by Ryan et.al [4] that at lowest spray released height, smaller droplets were formed and scattered outwards at quicker rates but less contribution in droplets volume compared to higher released height. Since uniformity spray distribution was the main aim of this simulation, it is suggested that aerial spraying at low released height ensuring that the particles trajectories is sufficient to reach the intended targets before drift occurs due to the initial airspeed as mentioned in the earlier studies by Dorr et.al [2] .…”

Section: Spray Coveragementioning

confidence: 96%

“…The sprayed deposition pattern is critical in aerial spraying works, illustrated the effects of aerial spraying works with optimum distance ranging not less than 2.4 m above the crop or ground compare to forestry application which is 6 m or higher. The turbulent dispersion, subjected to change and continue falling in effect of gravity magnitude which coincides at the end of the injection of the spray plume as proposed by Zhang et.al [3]. Generally, it was found that the maximum sprayed deposition area was achieved at the highest released height of 4.7 m compared for a released height of 3.7 m. Thus, a good combination of spray released height with low airspeed is significantly affected the aerial spraying deposition pattern.…”

Section: Spray Depositionmentioning

confidence: 99%

“…In the present work, an unsteady 3D CFD using Fluent version 15.0 from ANSYS® modelling was designed to simulate two-sub model; an airflow model [3] and a particle tracking model which are mutually coupled [4]. A Lagrangian approach representatives of approximate of 40000 droplets trajectories was utilized for all simulations.…”

Section: Methodsmentioning

confidence: 99%

“…Aerial spraying works involving pesticide released into atmosphere at certain height above the crop or forest to the ground. Thus it requires atomizers that are able to meet with stringent environmental law and also ensuring pesticide stays in the intended area [2,3,4]. Spray drift is undesirable, but still the important role of pesticides or plant protection products in modern agriculture is undeniable in terms of reducing pest attacks and increasing high yield [5,6].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A numerical analysis of flat fan aerial crop spray

Fesal

Fawzi

Omar

2017

IOP Conf. Ser.: Mater. Sci. Eng.

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View the article online for updates and enhancements. Abstract. Spray drift mitigation, in the agriculture aerial spraying literature, and spray quality in the application of plant protection products, still continues as two critical components in evaluating shareholder value. A study on off-target drift and ground deposit onto a 250 m strip were simulated through series of Computational Fluid Dynamic (CFD) simulations. The drift patterns for evaporating droplets were released from a constant aircraft velocity at 30 m/s (60 mph) carrying 20 m swath width spray boom with 12 fan-type nozzles at released height from the ground ranging from 3.7 m to 4.7 m. Droplet trajectories are calculated from the given airspeed with a Lagrangian model for particle dispersion excluding any wind effect perturbation. The proposed CFD's model predictions agreed well with cited literatures for a wide range of atmospheric stability values. The results revealed that there is considerable increased in spray drift and droplets trajectories with the increased in spray released height. It suggested that a combination of low aircraft spray released height with low airspeed is essential to improve spray quality and maximizing uniform deposition on the target area are significant in minimizing spray drift risks.

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Improving UASS pesticide application: optimizing and validating drift and deposition simulations

Tang,

Zhang,

Chen

et al. 2024

Pest Management Science

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BACKGROUNDAs unmanned aerial spraying systems (UASS) usage grows rapidly worldwide, a critical research study was conducted to optimize the simulation of UASS applications, aiming to enhance pesticide delivery efficiency and reduce environmental impact. The study examined several key aspects for accurate simulation of UASS application with lattice Boltzmann method (LBM). Based on these discussions, the most suitable grid size and simulation parameters were selected to create a robust model for optimizing UASS performance in various pest management scenarios, potentially leading to more targeted and sustainable pest control practices.RESULTSThe effect of stability parameter, grid size around the rotor and near ground, and parameters at wake flow were carefully analyzed to improve the precision of pesticide drift predictions and deposition patterns. Optimal grid sizes were identified as 0.2 m generally, 0.025 m near rotors, and a 0.1 + 0.2 m scheme for ground proximity, with finer grids improving accuracy but increasing computation time. Wake resolution and threshold significantly influenced simulation results, while wake distance had minimal impact beyond a certain point. The LBM's accuracy was validated by comparing simulated downwash flow and droplet deposition with field test data.CONCLUSIONThis study optimized UASS simulation parameters, balancing computational efficiency with accuracy. The validated model enhances our ability to design more effective UASS for pest management, potentially leading to more precise and targeted pesticide applications. These advancements contribute to the development of sustainable pest control strategies, aiming to reduce pesticide usage and environmental impact while maintaining crop protection efficacy. © 2024 Society of Chemical Industry.

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Numerical simulation of wake vortices of crop spraying aircraft close to the ground

Cited by 33 publications

References 11 publications

Research status and trends of downwash airflow of spray UAVs in agriculture

Research status and trends of downwash airflow of spray UAVs in agriculture

A numerical analysis of flat fan aerial crop spray

Improving UASS pesticide application: optimizing and validating drift and deposition simulations

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