Document Type

Thesis - Open Access

Award Date

2020

Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

First Advisor

Jeffrey Doom

Keywords

Agricultural Spraying, Computational Fluid Dynamics, Pulsed Spray, Spray Nozzles

Abstract

Computational fluid dynamics (CFD) is a tool used by engineers in many industries to study fluid flow. A relatively new industry to adopt the use of CFD is the agricultural industry. The present work seeks to understand whether CFD can be used to accurately model spray nozzles. A spray nozzle commonly used in agricultural spraying was simulated. First, the impact of factors such as mesh size, mesh type, and physics models have on the solution were investigated. Next, a method to pulse the spray was determined. This was required to compare simulation results with experimental data. A user-defined function was used to define a pulsed velocity inlet in order to pulse the spray. The domain was then extended to allow the examination of a slice 20 inches below the nozzle. The results were compared to experimental data collected from the Raven Sprayer Testbed. Results from these studies suggested that CFD could be used to model spray nozzles but the validity of the results is strongly related to the available computational resources. These simulations were carried out using Star-CCM+. Lastly, Large Eddy simulations were conducted to capture the liquid jet breakup within the spray plume. The results suggested that the liquid jet breakup could be modeled using CFD, but again sufficient computational resources are required. These simulations were performed in OpenFOAM.

Library of Congress Subject Headings

Spray nozzles.
Spraying and dusting in agriculture.
Computational fluid dynamics.
Spraying -- Computer simulation.

Format

application/pdf

Number of Pages

92

Publisher

South Dakota State University

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Rights Statement

In Copyright