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 18 of 18 for “"Wake Turbulence"”.
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Simulation-Based Analysis of Wake Turbulence Encounters in Current Flight Operations
… factor to any reduction in separation is wake turbulence. The potential for aircraft to encounter wake turbulence poses a threat to both safety as well as increased efficiency. This research effort seeks to develop a model that can be used to evaluate the potential for wake encounters in …
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Analysis of Potential Wake Turbulence Encounters in Current and NextGen Flight Operations
Wake vortices pose a threat to a following aircraft, because they can induce a roll and compromise the safety of everyone on board. Caused by a difference in pressure between the upper and the lower part of the wings, these invisible flows of air are a major hazard and have to be avoided by …
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A Computer Model to Predict Potential Wake Turbulence Encounters in the National Airspace
… the introduction of NextGen technologies, the wake vortex problem has become more important for airport capacity and the en-route air traffic operations. The vortices generated by heavy and super heavy aircraft can generate potential hazards to other aircraft on nearby flight paths. Moreover, …
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A system level study of new wake turbulence separation concepts and their impact on airport capacity
… procedures: specifically, new and emerging wake turbulence separation rules that could potentially increase runway capacity based on today's knowledge of wake vortex turbulence and technological capabilities. While legacy wake separation rules establish aircraft-classes based on weight of …
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Automatic Dependent Surveillance - Broadcast Enabled, Wake Vortex Mitigation Using Cockpit Display
Wake turbulence has the potential to cause accidents during the landing phase of flight. This thesis work documents the development and testing of a prototype cockpit display to help pilots avoid this wake turbulence using ADS-B technology. Several landing profiles of the wake generating aircraft …
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Anisotropic Turbulence Models for Wakes in an Active Ocean Environment
A set of second-moment closure turbulence models are implemented for the study of wake evolution in an oceanic environment. The effects of density stratification are considered, and the models are validated against laboratory experiments mimicking the stratified ocean environment, and against …
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The Design and Experimental Optimization of a Wingtip Vortex Turbine for General Aviation Use
… the vortex flow (reducing induced drag and wake turbulence) and also produces a thrust force component. The WVT also has the advantage of extracting the rotational energy of the vortex to turn a generator, which could be used to power onboard applications during normal or emergency flight …
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Effects of Turbulence Modeling on RANS Simulations of Tip Vortices
… this thesis is to quantify the effects of RANS turbulence modeling on the resolution of free shear vortical flows. The simulation of aerodynamic wing-tip vortices is used as a test bed. The primary configuration is flow over an isolated finite wing with aspect ratio, , and Reynolds number, . …
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Understanding Vortex Reconnection in Complex Fluid Flows
… behind aircrafts is thought to be a cause of wake turbulence, detrimental to air traffic control. We observe the reconnection process for three initial vortex tube set-ups; anti-parallel, orthogonal and anti-parallel with axial flow. From these we are able to identify each of the different …
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Estimation of Runway Throughput with Reduced Wake Vortex Separation, Technical Buffer and Runway Occupancy Time Considerations
… recovery of the runway throughput under Wake Turbulence Re-categorization (RECAT) Phase II and Time-based Separation (TBS) with a Runway Occupancy Time (ROT) constraint comparing with RECAT Phase I. This research uses aircraft performance parameters (runway occupancy time, approach speed, …
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Cross-shore transformation of breaking random waves in the surfzone
… on the surface of a breaking wave, and the turbulence, determines the wave-driven onshore-directed mass transport, the vertical structure of the compensating return flow (undertow), and the increase in the mean water level (setup). A two-phase Reynolds-Averaged Navier-Stokes (RANS) model and …
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Cross-shore Transformation of Breaking Random Waves in the Surfzone
… on the surface of a breaking wave, and the turbulence, determines the wave-driven onshore-directed mass transport, the vertical structure of the compensating return flow (undertow), and the increase in the mean water level (setup). A two-phase Reynolds-Averaged Navier-Stokes (RANS) model and …
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Broadband Noise Prediction of an Axial Compressor Operating at Low Reynolds Number
… to stay laminar and attached. Generation of turbulence is then mainly limited to the secondary flows at the hub and tip gap which account for a large proportion of the wake turbulence. The secondary flows also feed turbulence into the blade profile boundary layers in these regions. A hybrid …
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Wind and Wake Sensing with UAV Formation Flight: System Development and Flight Testing
Wind turbulence including atmospheric turbulence and wake turbulence have been widely investigated; however, only recently it become possible to use Unmanned Aerial Vehicles (UAVs) as a validation tool for research in this area. Wind can be a major contributing factor of adverse weather for …
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Residence time in coastal canopies
… layer that forms at the top of the canopy and wake turbulence generated by the stems. By allowing a coupled contribution of wake and shear layer mixing, a predictive formulation for the rate of vertical mixing in coastal canopies across a range of wave and canopy conditions is presented. …
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Use of fan rig data for the understanding and prediction of fan broadband noise and noise changes due to a variable area nozzle
… vane chord, vane<br/>stagger angle, and rotor wake turbulence intensity, turbulent length scale, and flow Mach<br/>number onto the cascade. These results are used to derive scaling power laws for the<br/>prediction of changes in broadband noise due to changes in these parameters. The …
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Development of Aircraft Wake Vortex Dynamic Separations Using Computer Simulation and Modeling
… presents a research effort to evaluate wake vortex mitigation procedures and technologies in order to decrease aircraft separations, which could result in a runway capacity increase. Aircraft separation is a major obstacle to increasing the operational efficiency of the final approach …
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Estimation of Runway Throughput with Reduced Wake Separation, Runway Optimization, and Runway Occupancy Time Consideration
… runway throughput gains using a reduced wake separation based on the 123 most prevalent aircraft in the United States fleet. The analysis considers Runway Occupancy Time (ROT) constraint factors and existing geometric design factors. This research extracts the historic data from Airport …