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Application of agrochemicals on crops is important for plants protection. Multiple factors influence the application of agrochemicals on plants such as climatic conditions, crop characteristics and spraying system design. There is a need for reliable methods to investigate these properties more precisely with low cost and in reasonable time. In the present study, the velocity distribution of an extended flat fan nozzle is investigated to determine the weak jet areas, which have high risks of droplet drift. Two methods are used and compared: the Particle Image Velocimetry (PIV) method used as an experimental approach versus a Computational Fluid Dynamics (CFD) with volume of fluid (VOF) integrating k-epsilon model as a simulation approach. The nozzle was operated at eight different pressures on a custom-made nozzle operating prototype while ANSYS 16 Fluent software was employed for the simulation approach. The obtained findings showed three significant results. First, the spray sheet (jet) has maximum velocity in its center. Second, the particles present in the central region of spray sheet have maximum kinetic energy and this region has the ability to hit the right target on the plant surface, while liquid particles present in the surroundings of this central area have less velocity with minimum kinetic energy and have maximum chances to be off-target during spraying. These particles can move away from the targeted surfaces easily even with very low wind velocity. Third, the study also showed that PIV and CFD simulation methods were in agreement and both showed reliable ways to measure the jet velocity and plot the velocity distribution under the sprayer nozzle. The applications of these findings are also discussed. [ABSTRACT FROM AUTHOR]

Distribution of agro-chemicals through sprayer nozzles is very important because there is a significant loss of agro-chemicals such as pesticides during spraying due to non-uniformity of droplet and off-target drift. Improving the efficiency of spray pattern would reduce energy, costs and also minimize environmental pollution. In this paper, we examine jet patterns to study the performance of water distribution during the spraying process. We present a method to quantify water amount from a sprayer jet by using Particle Image Velocimetry (PIV) system in combination with imaging processing. For this study, ten sets of images were acquired with a PIV system in double frame mode. Each set of images contained different numbers of doubleframed images: 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 at eight different pressures 25, 50, 75, 100, 125, 150, 175 and 200 kPa. The PIV images obtained were analysed using an image processing software for droplets and volume calculations. The results showed good agreement of both manual and PIV measurements and suggested that the PIV coupled with image processing technique can be used for a precise quantification of flow through sprayer nozzles. [ABSTRACT FROM AUTHOR]