Momentum and particle transport in a nonhomogenous canopy

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Title Momentum and particle transport in a nonhomogenous canopy
Publication Type thesis
School or College College of Engineering
Department Mechanical Engineering
Author Gould, Andrew W.
Date 2013-04
Description Turbulent particle transport through the air plays an important role in the life cycle of many plant pathogens. In this study, data from a field experiment was analyzed to explore momentum and particle transport within a grape vineyard. The overall goal of these experiments was to understand how the architecture of a sparse agricultural canopy interacts with turbulent flow and ultimately determines the dispersion of airborne fungal plant pathogens. Turbulence in the vineyard canopy was measured using an array of four sonic anemometers deployed at heights z/H ~ 0.4, 0.9, 1.45, and 1.95 where z is the height of the each sonic and H is the canopy height. In addition to turbulence measurements from the sonic anemometers, particle dispersion was measured using inert particles with the approximate size and density of powdery mildew spores and a roto-rod impaction trap array. Measurements from the sonic anemometers demonstrate that first and second order statistics of the wind field are dependent on wind direction orientation with respect to vineyard row direction. This dependence is a result of wind channeling which transfers energy between the velocity components when the wind direction is not aligned with the rows. Although the winds have a strong directional dependence, spectra analysis indicates that the structure of the turbulent flow is not fundamentally altered by the interaction between wind direction and row direction. Examination of a limited number of particle release events indicates that the wind turning and channeling observed in the momentum field impacts particle dispersion. For row-aligned flow, particle dispersion in the direction normal to the flow is decreased relative to the plume spread predicted by a standard Gaussian plume model. For flow that is not aligned with the row direction, the plume is found to rotate in the same manner as the momentum field.
Type Text
Publisher University of Utah
Subject Gaussian Plume model; Momentum Transport; Nonhomogenous canopy; Particle releases; Particle Transport; Wind channeling
Dissertation Institution University of Utah
Dissertation Name Master of Science
Language eng
Rights Management Copyright © Andrew W. Gould 2013
Format application/pdf
Format Medium application/pdf
Format Extent 4,122,444 bytes
Identifier etd3/id/3391
ARK ark:/87278/s6zw4v75
Setname ir_etd
ID 196955
Reference URL https://collections.lib.utah.edu/ark:/87278/s6zw4v75
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