Dissertation/Thesis Abstract

Description of coherent structures in the atmospheric boundary layer by model reduction of the surface pressure
by Lyons, Gregory William, M.S., The University of Mississippi, 2012, 58; 1532120
Abstract (Summary)

The flow of coherent turbulent structures into a wind turbine is associated with vibrational blade excitation. Successful forecasting of such turbulent events for control system input would increase the lifetime of turbine components. The coherence of these features suggests description by model reduction. To this end, an array of pressure transducers was deployed on the ground at Reese Technology Center in Lubbock, Texas, and the pressure fluctuations were recorded over nearly two diurnal cycles. A program for computation of the dynamic mode decomposition was developed with special consideration for the case of a non-stationary, nonlinear system. A simulated surface-pressure perturbation was first decomposed, to inform the interpretation of experimental data. Several sets of surface-pressure data were decomposed for various meteorological conditions. The resulting dynamic modes and eigenvalues describe the spatial and temporal coherence of local features in the atmospheric boundary layer. In each case, modes were identified that can be associated with wave-like pressure fluctuations that propagate either at convective or acoustic speeds.

Indexing (document details)
Advisor: Murray, Nathan E.
Commitee: Raspet, Richard, Waxler, Roger
School: The University of Mississippi
Department: Aeroacoustics
School Location: United States -- Mississippi
Source: MAI 51/04M(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Atmospheric sciences
Keywords: Atmospheric boundary layer, Coherent turbulence, Dynamic mode decomposition, Infrasound, Model reduction, Wall pressure fluctuations
Publication Number: 1532120
ISBN: 9781267866936
Copyright © 2019 ProQuest LLC. All rights reserved. Terms and Conditions Privacy Policy Cookie Policy
ProQuest