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 20 of 43 for “"turbulent structures"”.
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Turbulent structures in smooth and rough open channel flows: effect of depth
… to study the effect of the flow depth on turbulent structures in smooth and rough bed open channel flow. When the rough bed is introduced in the shallow flow, the local turbulence near the roughness element intensifies and becomes highly heterogeneous. The model roughness under study …
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Investigation of horizontal meteorological structures in comparison to turbulent structures at a forest edge
… about prevailing meteorological conditions, turbulent and coherent structures and exchange processes of heterogeneous forest ecosystems. Therefore, this thesis is related to the joint research project EGER IOP3 (ExchanGE processes in mountainous Regions – Intensive Observation Period 3), …
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Flow Visualizations and Measurements of Turbulent Structures in Drag-Altered Axisymmetric Compressible Base Flows
… of the flowfield are shown to de-stabilize the turbulent structure organization. The mean structure statistics of all drag-altered flowfields demonstrate that the dominant organization present upstream is significantly weakened or lost due to passage through these regions. When the base bleed …
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A methodology based on local resolution of turbulent structures for effective modeling of unsteady flows
… seen a continuous growth of CFD simulations of turbulent phenomena, which has been made possible by the tremendous reduction achieved in cost per floating point operation. The need for accurate, yet computationally effective, transient methods has drawn particular attention to hybrid turbulence …
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Mean Flow Characteristics and Turbulent Structures of Turbulent Boundary Layers in Varying Pressure Gradients and Reynolds Numbers
Turbulent boundary layers flowing over a smooth surface were studied to understand the influence of varying pressure gradients and flow Reynolds number on the boundary layer growth and mean turbulent properties. The test was conducted in the Virginia Tech Stability Wind Tunnel with a 0.914 m chord …
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Large eddy simulation of turbulent vortices and mixing layers
… is used to study the transitional and turbulent structures of vortices and free shear layers. The recently developed dynamic model and the basic Smagorinsky model are utilized to model the subgrid-scale(SGS) stress tensor. The dynamic model has many advantages over the existing SGS …
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The structure of a trailing vortex wake
… the wake by the vortex. Stretching intensifies turbulent structures aligned with the stretching direction. Two-point measurements were made in the 2-D and 3-D regions of the wake to reveal the spanwise extent of the instantaneous turbulent structures in the wake. A high correlation was found at …
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Spatiotemporally-Resolved Velocimetry for the Study of Large-Scale Turbulence in Supersonic Jets
… noise has many interacting features, large-scale turbulent structures are believed to dominate the noise produced by heated supersonic jets. To characterize the unsteady behavior of these large-scale turbulent structures, which can be correlated over several jet diameters, a velocimetry technique …
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A study of the large-scale structure in a supersonic slot injected flow field
Large-scale structures were studied in a supersonic stream of air (M = 3) with tangential supersonic slot injection of air (M = 1.7). A dual constant temperature hot-wire probe was used to determine the average structure angles and the characteristic length of the turbulent structures. A zero …
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Modeling and Large Scale Simulations of Thermohaline and Particulate Density Currents
… of the flow and the rich interaction between turbulent structures with a wide range of scales. Front spreading velocity, Kelvin-Helmholtz vortex dynamics, lobe and cleft formation and evolution, flow patterns, and bed shear stress patterns, are visualized and explored in detail. The simulation …
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Wall-Jet Turbulence and Mixing Control by Way of a Pulsed Inlet Velocity
… = 0.0048 experience a reduction in the number of turbulent structures while becoming more stable, indicating potential drag reduction. Cases at Sr = 0.02 experience a frequent energy re-supply from the inlet that helps maintain large turbulent structures at further downstream locations, useful for …
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Degassing Behaviour of Basaltic Open Vent Volcanoes
… eruptions. The second problem centres around turbulent structures in vertical and wind-blown plumes. First, the injection of gas into a cylinder, which was filled with a water-glycerol mixture and particles, was investigated. These analogue experiments provides the framework of a model for …
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Experimental Investigation of a Lean, Premixed Gas Turbine Combustor Using Advanced Laser Diagnostics
… a combustion flow field dominated by large-scale turbulent structures. Stabilization of the flame occurred primarily in the side recirculation zone at the edge of the premixer exit. Single-shot temperature measurements were made using coherent anti-Stokes Raman scattering at the two pressure drop …
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Description of Coherent Structures in the Atmospheric Boundary Layer By Model Reduction of the Surface Pressure
<p>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 …
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Extraction of turbomachinery loss mechanisms from high-fidelity simulations
… the flow, where the evolution of multiple flow structures can give rise to the mean behaviour. To make better use of DNS to inform design, this work aims to investigate unsteady flow structure in realistic turbomachinery flows using high-fidelity simulations, and develop tools which can be …
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Free surface dynamics in shallow turbulent flows.
… govern free surface behaviour in depth-limited turbulent flows. Experimental data has shown that the turbulence properties at a point near the free surface relate directly to the properties of the free surface pattern. This would suggest a direct linkage between the free surface and the …
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Evaluation of the Interaction Between Flow Turbulence and Corrosive Material Transport Around Bridge Piers
… study investigates the influence of corrosion on turbulent flow around bridge piers and its implications for structural integrity and environmental safety. By examining the interaction between flow turbulence and corrosion-induced particles, the research highlights their effects on vortex …
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Empirical mode decomposition applied to planar and volumetric velocity field measurements of a supersonic separated flow
… that a technique able to identify instantaneous turbulent structure within it is valuable. In this study, multi-dimensional extensions of fast and adaptive empirical mode decomposition (FAEMD) are implemented on both three-component planar and volumetric velocity fields of a Mach 2.5 supersonic …
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Modeling the Effect of Particle Diameter and Density on Dispersion in an Axisymmetric Turbulent Jet
… entrainment behavior within axisymmetric turbulent jets is of significant interest to many areas of study. Research into multiphase flows within turbulent structures has primarily focused on specific geometries for a target application, with little interest in generalized cases. In this …
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Bio-Inspired Trailing Edge Noise Control: Acoustic and Flow Measurements
… and by sheltering the trailing edge from turbulent structures with the shear layer they create.
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