Numerical simulation of spray ejection from a nozzle for herbicide application: Comparison of drag coefficient expressions
| Autor: | Armando Benito Brizuela, Carlos G. Sedano, Cesar Augusto Aguirre |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Drag coefficient media_common.quotation_subject Nozzle GLYPHOSATE INGENIERÍAS Y TECNOLOGÍAS Horticulture Computational fluid dynamics Inertia 01 natural sciences Mecánica Aplicada Ciencias de la Tierra y relacionadas con el Medio Ambiente Physics::Fluid Dynamics symbols.namesake Aerodynamic drag Particle velocity SPRAY EJECTION Mathematics media_common Ingeniería Mecánica SIMULATION MODELS business.industry Reynolds number Forestry EPA 04 agricultural and veterinary sciences Mechanics HERBICIDES Computer Science Applications Ciencias Medioambientales 040103 agronomy & agriculture symbols 0401 agriculture forestry and fisheries Particle business Agronomy and Crop Science CIENCIAS NATURALES Y EXACTAS 010606 plant biology & botany |
| Popis: | This paper compares the different expressions of drag coefficients using a Computational Fluid Dynamics (CFD) code. This code is a Large-eddy Simulation-Lagrangian Stochastic Model (LES-STO) to simulate liquid particle ejection from a HARDI™ ISO F110-03 nozzle. The results are compared to laboratory measurements of the vertical component of the liquid particle velocity. To do this, the physical process was segmented from the trajectory of the particles into the following two stages: a Transitional Stage and a Sedimentation Stage. At each of these stages, speeds, Reynolds numbers and drag coefficients were calculated independently for each particle during each time step. A model was used that allows for a 1:1 simulation with respect to the applied volume, using a time step of 2 · 10−4 s, evaluating a total of 15,500,000 particles in 40 s of simulation. For the aerodynamic drag coefficient, six different expressions were compared with the laboratory tests; the one proposed by Turton and Levenspiel (1986) achieved the best agreement of the velocity values as shown in the Chi-square goodness of Fit and F-test variance. With these data, it was possible to validate what the Environmental Protection Agency (EPA) described in its pesticide specifications. Potential drift is significantly reduced when the nozzle is placed at a height of 0.75 m because particles larger than 300 µm do not reach sedimentation velocity before impacting the ground. For these drops, the inertia forces do not reach equilibrium with the traction forces, so the particles maintain the ejection inertia. Unfortunately, there is not presently a technology that guarantees the exclusive application of the diameters that are required on the product label. Fil: Sedano, Carlos German. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; Argentina Fil: Aguirre, Cesar Augusto. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Brizuela, Armando Benito. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; Argentina |
| Databáze: | OpenAIRE |
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