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 “"airframes"”.
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Characterization of flow control using programmable multi-directional plasma actuators
… the efficiency and control of lifting bodies and airframes. The research demonstrates that the described programmable, multi-directional, plasma actuators may be used to create an assortment of desired flows and to aid in the control of airframes.
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Maintaining NASTRAN: the politics and technics of aerospace computing
… developed by NASA for solving problems of airframes and space structures. The story of NASA and NASTRAN demonstrates a structural imbalance between social groups of NASTRAN and results in the revision of NASTRAN in favor of aerospace users. Chapter Four recounts Feynman's concerns regarding …
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A review and analysis of upgrades to Naval and Air Force aircraft to identify similarities and trends from fiscal year 1998 to 2013
… to capture which upgrades were pursued on what airframes within each type/model/series of aircraft. As a result of this project, the USD(AT&L) will have a foundation upon which further research may build to better discern whether there is an optimal interval between modifications. The intent of …
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High Fidelity and Efficient Computations of Dynamic Loads for Multidisciplinary Design Optimization of Flexible Transport Aircraft
… current state-of-the-art design optimization of airframes is tightly wounded to its loads analyses as the process is usually conducted employing a deterministic set of critical load cases. The sheer number of scenarios required to estimate the critical loading conditions prevent these two …
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Scalable and Modular Manufacturing of Insect-Scale Aerial Robots Towards Swarm Flight Demonstrations
… employed to fabricate static components such as airframes and connectors, significantly streamlining the production process. This modular approach improves assembly efficiency and repairability, reducing fabrication time by more than half. Using this methodology, two sub-gram MAVs successfully …
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Corrosion And Wear Resistance Of Titanium- And Aluminum- Based Metal Matrix Composites Fabricated By Direct Metal Laser Deposition
… properties for aerospace applications such as airframes, reinforcement materials and joining elements. In this research, such coatings were developed by direct metal laser deposition with a powder-fed fiber coupled diode laser. The MMC formulations consisted of pure titanium and aluminum …
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Static and dynamic large deflection flexural response of graphite- epoxy beams
… support of crashworthiness studies of composite airframes, the present study was undertaken to understand the large deflection flexural response and failure of graphite-epoxy laminated beams. The beam specimens were subjected to eccentric axial impact loads and to static eccentric axial loads, in …
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The Carrier Readiness Team realizing the vision of the Naval Aviation Enterprise
… parts, personnel and production of replacement airframes. It was further enlarged to encompass the aircraft carrier fleet. This thesis examines the environment that drove the need to employ an enterprise construct, comparing it to the systems engineering approach used to bring new material …
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Investigation of alternative rotorcraft powerplant configurations for improving airframe performance
… modeling was conducted using a variety of airframes, created using industry standard practices. The identified engines were conceptually implemented in the aircraft through standard engine swaps replacing the gas turbines with piston engines, hybrid designs incorporating both a gas turbine …
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A modular simulation environment for the improved dynamic simulation of multirotor unmanned aerial vehicles
… represent more complicated three-dimensional airframes or realistic environmental effects like wind resistance or dynamic thrust. The thesis then outlines an improved dynamic model that does not require any of the previous simplifying assumptions. This allows the model to be used for just …
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Application of electromagnetic scattering reduction techniques for small unmanned aerial vehicles
… iterate upon novel designs. Each of the modified airframes are compared to the baseline measurements to evaluate the effectiveness of the electromagnetic scattering reduction techniques. The work described in this thesis advances the understanding of what electromagnetic scattering reduction …
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Design of a Hybrid Micro Aerial Vehicle Concept with Multicopter and Vectored Thrust Modes of Flight
… to the performance of current autonomous drone airframes in similar tasks. Finally, the development of the jet vane thrust vector control (TVC) system used to steer REAVER during rocket-like flight is discussed. A novel small-scale jet vane design utilizing additive manufacturing is presented …
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Guidance, navigation and control of a small, unmanned blended wing body aircraft
… so as to be broadly applicable to a variety of airframes. Subsequently, the Skywalker X8 airframe was modelled, using existing literature, and then characterised so as to establish what the goals might be for an optimal set of controllers. An autopilot was then designed which was optimised so as …
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What's next for the airliner? : historical analysis and future predictions of aircraft architecture and performance
… block fuel. Results indicate that for existing airframes, namely the 737 and A320, performance is expected to increase by 6-38% relative to the 737MAX and A320neo within the next 10-14 years, depending on engine technology development. For a new aircraft with the dominant architecture and …
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Application of a Helmholtz resonator excited by grazing flow for manipulation of a turbulent boundary layer.
… grazing flow and it can be fitted to existing airframes with minimal manufacturing requirements. Hence it can potentially be an ideal solution for a wall-based flow control device. This research provides an insight into the behaviour of the flow in the vicinity of the resonator and assesses the …
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Modeling the Impact of Helicopter Vibrations on the Musculoskeletal Health of US Army Blackhawk Helicopter Pilots
… of pilot experience factors (flight hours, airframes, operating theatres, etc.), and by representing the maladaptive posture of the pilots with a computational simulation based on experimental pilot data; a full picture is developed of the risk of issue related to the near and long-term …
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Robust Image-Based Visual Servo Control of an Uncertain Missile Airframe
<p>A nonlinear vision-based guidance law is presented for a missile-target scenario in the presence of model uncertainty and unknown target evasive maneuvers. To ease the readability of this thesis, detailed explanations of any relevant mathematical tools are provided, including stability …
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Analysis Methodology Determination For Calculating Load Distributions of Complex Fastened Joints
Fastened joints are everywhere on an aircraft, especially on a built-up, riveted airframe. These joints, particularly in the rotorcraft environment in metallic structures, are sources of stress concentrations that lead to fatigue damage over time. Understanding the load distribution and stresses …