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 27 for “"Wake Vortex"”.
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Variable Fidelity Studies in Wake Vortex Evolution, Safety, and Control
… investigation toolkit for analysis and reporting wake vortex safety system (SITAR WVSS) code, which is a dynamic low-fidelity model addressing generation, evolution, and interaction of the leader-aircraft wake vortex with the follower-aircraft lifting surfaces.</p> <p>The first part of the …
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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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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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Modeling of Rotor Wake Vortex Dynamics and Interactions in Non-Homogenous Vertiport Environments
… however the effects caused by the way the wake develops can cause significant challenges in implementing electric vertical takes off and landing devices (EVTOL’s) in modern urban environments. Acoustic data was also observed in this sphere with the main goal being to observe the impact the …
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The influence of runway occupancy time and wake vortex separation requirements on runway throughput
… runway capacity; runway occupancy and wake vortex separation, and under what conditions each becomes a constraint to runway capacity. A detailed analysis of runway occupancy time measurements and wake vortex separation measurements is performed for Boston, Philadelphia, New York La …
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Determination of Bragg Scatter in an Aircraft Generated Wake Vortex System for Radar Detection
… detection and tracking of wingtip generated wake vortices is important for hazard avoidance especially near airports. Aircraft that fly through these hazardous vortices experience sudden induced roll. Experiments have demonstrated that there is sufficient radar cross section for remote …
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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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Effects of reduced IFR arrival-arrival wake vortex separation minima and improved runaway operations sequencing on flight delay
(cont.) 65.6% and 67.0% and the average NAS delay by 24.3% and 24.7% relative to the FIFO and Serve-the-Longest-Queue algorithms respectively.
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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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Vortex driven flame dynamics and combustion instability
… are acoustic wave-flame interactions, flame-vortex interactions, equivalence ratio fluctuations, flame-wall interactions and the unsteady stretch rate. To investigate the flame- vortex interaction mechanism, a parametric study is performed in single and double expansion dump combustors. 2-D …
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Effects of upstream wake phasing on the performance of transonic compressors
The effect of the upstream wake phase on the work input (i.e., rise in stagnation enthalpy across the blade row) of a transonic rotor is examined computationally and analytically. It is found that the compressor work depends on the path followed by the wake vortices as they travel through the rotor …
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A Volume-Force Synthetic Disturbance Approach for High-Fidelity of Unsteady Fluid Structure Interactions
… fan, the effect of turbulence intensity on wake vortex evolution.</p> <p>In particular the effects of oblique vortical gust modes on airfoil unsteady aerodynamic and acoustic responses due to its interaction with an impinging 3D time-harmonic gust and turbulence are addressed first. Several …
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The effect of Whitcomb winglets and other wingtip modifications on wake vortices
… wingtip configurations to determine their wake vortex characteristics. The trailing wingtip vortex was probed by a 1/8 inch diameter five hole yawhead pressure probe in the VPI & SU Stability Wind Tunnel. The vortex tangential and axial velocity profiles are compared at five and twenty …
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Aeroelastic Analysis of Membrane Wings
… pitch and plunge are simulated using a 3-D, free wake, vortex lattice method (VLM), and structural characteristics of the wing are simulated as a membrane supported by a rigid frame. The aerodynamics is validated by comparing the results from the VLM model for constant angle of attack flight, …
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Physics-based flame dynamics modeling and thermoacoustic instability mitigation
… anchoring configurations investigated were the wake-stabilized flames and the perforated-plate stabilized flames. In order to investigate the wake-stabilized flames, experiments were performed in an atmospheric pressure, backward-facing step combustor. In this configuration, the dynamics are …
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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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Structure and Dynamics of a Reacting Jet Injected into a Vitiated Crossflow in a Staged Combustion System
… The time averaged flow field shows a steady wake vortex very similar to that seen in the wake of a cylindrical bluff body which helps to stabilize the reaction zone within the wake of the jet. Jet with J = 8 had a deeper penetration into the crossflow as compared to J = 3 jet. Velocity field …
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Approximate Algorithms for the Combined arrival-Departure Aircraft Sequencing and Reactive Scheduling Problems on Multiple Runways
… To prevent the dangers associated with wake-vortex effects, separation times enforced by Aviation Administrations (e.g., FAA) are considered, adding another level of complexity given that such times are sequence-dependent. Due to the problem being NP-hard, it is computationally difficult …
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Flapping wings for dual aerial and aquatic propulsion
… flight. Additionally, I elucidate the wakes of these complex wing trajectories using dye visualization, correlating the wake vortex structures with simultaneous force measurements. To inform the design space, I also analytically derive a low order state-space adaptation of the unsteady …
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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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