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 24 for “"Wind Gusts"”.
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Large Eddy Simulation Of Surface Pressure Fluctuations Generated By Elevated Gusts
Wind gusts cause substantial damage to wind turbines. If these damaging winds could be detected prior to their interaction with the turbine, the turbine rotor can be decoupled from the generator and gearing system to prevent damage during the gust event. This would significantly reduce wind turbine …
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Quality control and analysis of an updated wind gust data set in the United States
… the development of an updated 51-year peak wind gust data set for 679 Automated Surface Observing Systems (ASOS) stations across the Continental United States (CONUS) and explores limitations and implications for long return period wind speed estimation. In total, the data set contains more …
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Environmental Influences on Tree-driven Karst Bedrock Physical Weathering
… uptake or generate forces on rock in response to wind gusts, these processes have not been investigated in temperate karst regions until now. I monitored forces at the root-rock interface for an American elm and Hackberry tree between September 2019 and May 2020. I used piezoelectric force sensors …
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Development of a light-weight manipulator system for an omni-directional multi-rotor platform
… position a sensor in environments where wind gusts are present. In addition to its ability to complete disturbance rejection using visual servoing, the manipulator system provides the potential for pick-and-place operations. Physical testing of the prototype verified its ability to detect …
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Maneuver-Based Motion Control of a Miniature Helicopter
… in the presence of disturbances such as wind gusts, turbulence, sensor noise, and uncertain initial conditions. For the specific plant formulations and trajectories presented, performance is comparable for both control approaches; however, it is possible to improve controller performance …
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Control of cooperative unmanned aerial vehicles
… trajectory tracking under the presence of wind–gusts. The efficiency of the proposed control methods was verified through extended experimental studies. The final quadrotor design utilizes a powerful control unit, a sensor system that provides state estimation based on inertial sensors, …
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Design and Simulation of a Model Reference Adaptive Control System Employing Reproducing Kernel Hilbert Space for Enhanced Flight Control of a Quadcopter
… unmanned aerial vehicle (UAV) operations such as wind gusts and payload variations. By incorporating RKHS, we introduce a non-parametric, data-driven approach that significantly enhances system adaptability to in-flight dynamics changes. The research focuses on the design, simulation, and analysis …
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A Case Study of a High-Precipitation Supercell-Bow Echo Transition on 4-5 June 2008
… BE transition, the parent HP supercell produced wind gusts of over 50 knots, hail up to 2.75” in diameter, and four EF1 tornadoes. One of the tornado-producing low-level mesocyclones was sampled by the StickNet array and is compared to previous observations of tornadic and non-tornadic low-level …
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Design of a Fan-Based Test Stand for Evaluating Multicopter Handling in Turbulent Flow
… fans arranged in an L-shape frame, creating wind gusts that simulate the non-linear turbulent wind experienced by eVTOL. This also aids the Eagle Flight Research Center (EFRC) in their efforts to better understand how disturbances affect the handling qualities of both quadcopter drones and …
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Sand dune movement and its impact on human activities in the North Western coast region of Libya. An analysis of the sediment characteristics of sand dunes, and their movement using satellite images, and the effects of encroachment on farms assessed by a questionnaire survey.
… model proposed by Bagnold, which correlates wind shear velocity with particle size, in order to predict likely sand movement. It was found that 60% of sand grains within the study area have a diameter of less than 0.25 mm, making them liable to be moved by the wind speeds recorded, …
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Stability behaviour and dynamic response of cooling towers subjected to wind loading
… The shells are subjected to increasing wind pressures (speeds) to observe the trends in the critical buckling pressures/speeds at which the shell first buckles and the corresponding buckling modes. The cooling tower's geometry is changed in a systematic manner to obtain the relationship …
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Robust post-stall perching with a fixed-wing UAV
… UAV's perching performance in the presence of wind gusts. Very quickly, it becomes apparent that the glider can not reliably perch in wind. To address this, I describe a control approach for mitigating the effects of wind on aircraft performance and propose an experiment for testing this …
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Ducted Fan Aerodynamics and Modeling, with Applications of Steady and Synthetic Jet Flow Control
… exhibit a large nose-up pitching moment during wind gusts and when transitioning from hover to forward flight. Understanding ducted fan aerodynamic behavior and how it can be altered through flow control techniques are the two prime objectives of this work. This dissertation provides a new …
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Distributed LQR control of multi-agent systems
… to environmental disturbances such as nonuniform wind gusts acting on a formation of UAVs and to the loss of communication between two neighbouring UAVs.
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Mitigation of Gust Loads Through Pitching
Wind gusts can cause large loads on aerial vehicles, affecting their controllability and hindering their performance. The negative impact is especially significant for small vehicles, which experience relatively stronger gusts due to their low speeds. This raises the necessity of a control approach …
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Unsteady Aerodynamics of Wing-Gust Encounters
Wind gusts can be highly detrimental to the performance of fixed wing aircraft. At low flight speeds, gusts transverse to the lifting surfaces can cause massive changes to the angle of incidence, fluctuations in lift and drag, and result in flight instability. This may be catastrophic for small …
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Unsteady Aerodynamics of Wing–Vortex Gust Encounters
Wind gusts induce severe unsteady loads on low-speed aerodynamic devices, limiting the usability of small, slow-flying aircraft such as drones. Expanding the range of conditions under which these aircraft can safely operate requires control systems that can provide the necessary mitigating actions …
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Simultaneous Energy Harvesting and Vibration Control via Piezoelectric Materials
… flight. If the wing experiences any strong wind gust, it will sense the increased vibration levels and provide vibration control to maintain its stability. This work holds promise for improving performance of small UAVs in wind gusts. The proposed multifunctional wing spar integrates a …
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Detection of long-range dependence : applications in climatology and hydrology
… is the assessment of the maximum strength of wind gusts, which is important for designing wind turbines. The detection of long-range dependence is also a relevant problem in the exploration of financial market volatility. With rephrasing the detection problem as a model selection task and …
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