Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"Boundary Layer Turbulence"”.
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Estimating atmospheric boundary layer turbulence in the marine environment using lidar systems with applications for offshore wind energy
Estimating turbulence in the marine-atmospheric boundary layer is critical to many industrial, commercial and scientific fields, but of particular importance to the wind energy industry. Contributing to both the efficiency of energy extraction and the life-cycle cost of the turbine itself, …
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Estimating atmospheric boundary layer turbulence in the marine environment using lidar systems with applications for offshore wind energy
Estimating turbulence in the marine-atmospheric boundary layer is critical to many industrial, commercial and scientific fields, but of particular importance to the wind energy industry. Contributing to both the efficiency of energy extraction and the life-cycle cost of the turbine itself, …
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Impact of the boundary layer on pointing and tracking in airborne free-space laser communication links
… atmospheric scintillation, platform jitter, and boundary layer turbulence. This research investigated the tracking challenge using a focal plane array sensor with centroid and peak tracking algorithms. Also investigated was the use of a deformable mirror to recreate optical phase distortions from …
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Toward Closing the Urban Surface Energy Balance Using Satellite Remote Sensing
… novel techniques that combine traditional boundary layer turbulence measurements and advanced remote sensing methods are presented as solutions to advance our understanding of urban surface energy balance. Here, new methodologies are developed that apply remote sensing-based algorithms to …
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Statistical Models for Extreme Events in Atmospheric Processes
… characterizing extremes events in rainfall and boundary layer turbulence, including contributions along three main lines of inquiry:</p><p>1) Developing extreme value models able to reduce estimation uncertainty in the case of short rainfall time series. To this end, a non-asymptotic approach is …
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Experimental Investigation of Flow Control Techniques To Reduce Hydroacoustic Rotor-Stator Interaction Noise
… fluid noise in submersible vessels are the boundary layer turbulence along the forebody and propulsor fluid-structure interaction. The propulsor contains several locations of such interaction, one of which was investigated in this research. Specifically, this research focused on …
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The spectral characteristics of wind-farm power output
… wind-power variability is due to atmospheric turbulence. Power fluctuations at time scales such as these are important for maintaining frequency regulation on the power grid. This thesis presents a holistic, physics-based approach to modeling the spatio-temporal structures of the atmospheric …
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Turbulence structure and flow resistance in oscillatory boundary layer flows
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2022-12-01
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The steps in the development of an atmospheric vorticity meter
This thesis describes the steps necessary to develop an acoustic vorticity meter for the atmosphere. The analysis is based on Benthic Acoustic Stress Sensor (BASS) technology that is currently used for similar acoustic measurements in the ocean. Compared to sonic anemometer measurements, the BASS …
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Effect of Boundary-Layer Tripping on Turbulence Generation and Trailing-Edge Noise in Transitional Airfoils
… airfoil surface show that our prediction of the boundary layer and turbulence intensities are consistent with that of experimental results. Tripping, while it does modify the initial transition process, has little effect on the flow fluctuations near the trailing edge.</p> <p>The calculated …
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Effects of a Heated Turbulent Boundary Layer on Surface Pressure Fluctuations
… fluctuations in a fully turbulent atmospheric boundary layer (ABL) can give information about the velocity field and turbulence. This is of particular importance to the future of wind energy to predict the incoming velocity flow field of wind turbines so as to actively control them for peak …
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Quasi-coherent structures in the marine atmospheric boundary layer
Turbulence research in the laboratory over the past three decades has confirmed the existence of quasi-coherent structures amidst the chaos of a turbulent boundary layer. It has been observed that a quasi-periodic phenomena called "bursting" accounts for a major contribution to the turbulent …
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Amplitude modulation of velocity and wall shear stress in turbulent channel flow with hemispherical roughness
"Near-wall turbulence cycles tend to be self-sustained in low Reynolds number wall-bounded turbulent flows. However, large-scale structures that reside in the outer region of the flow grow more energetic as Reynolds number increases and impart strong ""footprints"" on the near-wall turbulence. In …
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Fluid Dynamics and Surface Pressure Fluctuations of Two-Dimensional Turbulent Boundary Layers Over Densely Distributed Surface Roughness
… two-dimensional zero pressure gradient turbulent boundary layers over 5 geometries of three-dimensional densely distributed surface roughness. A 3-velocity component laser Doppler velocimeter was used to measure instantaneous velocities. These measurements permitted an independent estimate of skin …
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A study of the velocity structure in a marine boundary layer : instrumentation and observations
… of a unique flow measuring instrument for bottom boundary layer studies in the marine environment is documented. The effectiveness of the instrument in acquiring data with which models of near bottom flows in the ocean can be tested is demonstrated by the results of a field experiment in Vineyard …