Inaug.-diss.--Münster. / Lebenslauf. At head of title: Anglistik. "Anhang. Der brief Pineros über seine unabhängigkeit von Ibsen": p. 65. "Literatur": p. vii-viii.

Thesis--Universität Hamburg. / Includes bibliographical references (p. 273-285).

Thesis (doctoral)--Université René Descartes-Paris V, Faculté des sciences humaines et sociales, Sorbonne, 1999. / Includes bibliographical references (v. 2, p. 652-675).

Thesis (M. S.)--History, Technology and Society, Georgia Institute of Technology, 2009. / Committee Chair: Jonathan Schneer; Committee Member: Dr. John Krige; Committee Member: Dr. John Tone; Committee Member: Dr. Gus Giebelhaus; Outside Reader: Dr. David Edgerton.

The feasibility of converting an existing internal combustion powered general aviation aircraft to battery electric propulsion was studied. The theoretical performance of various types of airframes with battery electric propulsion systems was compared to determine which type of airframe would be best suited for conversion. It was found that battery electric propulsion is best used in aircraft intended for slow speed, efficient flight and carrying limited payload which is a mission typically flown in motor gliders. A reference motor glider was selected and a conceptual power system packaging design study was performed. The study determined that a critical component of the power system packaging design was the technical feasibility of packaging the batteries inside of the wing structure. This was driven by center of gravity restrictions. Technical concerns related to a battery-in-wing design were investigated, included wing aeroelastic performance, wing stiffness and wing strength. The results showed that aeroelastic flutter was not a driving design criteria for the reference airframe used as the physical size of the battery did not allow for them to be packaged in wing locations that detrimentally affected flutter performance. The battery packaging layout was instead driven by access for battery maintenance, battery safety and the battery thermal management system. Overall weight change from packaging the batteries in the wing compared to the fuselage was found to be negligible. The resulting aircraft conceptual design indicated a powered flight range with reserves of over 200 miles and a powered flight endurance of greater than 3 hours with 2 persons onboard.

The Cal Poly SLO Turbo-Prop Racer (TP Racer) is a vehicle in development with the goal to break the world record for fastest turbo-prop aircraft measured over a 3-kilometer strip. This thesis presents the structural design, modeling, and analysis of the wing of Cal Poly SLO TP Racer. Methodology behind analyzing the wing is presented through finite element modeling elements and a mesh study. This is followed by development of structure through geometry and laminate estimations. The wing structure estimates and loading conditions are then modeled in FEMAP. Initial estimates are analyzed and reviewed – overbuilt, underbuilt, and incorrectly modeled regions of the structure are corrected. Finally, a refined finite element model is analyzed to present a satisfactory aircraft wing.

No description available.

The material presented in this thesis uses concepts of the finite element and doublet panel methods to develop a structural-aerodynamic coupled mathematical model for the analysis of a morphing wing tip composed of smart materials. Much research is currently being performed within many facets of engineering on the use of smart or intelligent materials. Examples of the beneficial characteristics of smart materials might include altering a structure's mechanical properties, controlling its dynamic response(s) and sensing flaws that might progressively become detrimental to the structure. This thesis describes a bio-inspired adaptive structure that will be used in morphing an aircraft's wing tip. The actuation system is derived from individual flexible matrix composite tube actuators embedded in a matrix medium that when pressurized, radical structural shape change is possible. A driving force behind this research, as with any morphing wing related studies, is to expand the limitations of an aircraft's mission, usually constrained by the wing design. Rather than deploying current methods of achieving certain flight characteristics, changing the shape of a wing greatly increases the flight envelope. This thesis gives some insight as to the structural capability and limitations using current numerical methods to model a morphing wing in a flow. / Master of Science

This investigation examines a new concept in airliner configurations from an experimental aerodynamics point of view. The concept proposes mounting the fuselages at the tips of a low aspect ratio wing. The motivation for this configuration is to provide an increase in the number of passengers carried with no increase in span over conventional designs. An additional motivation is the change in the wake flow of the wing, due to the fuselages and vertical tails, which may reduce the effect of the trailing vortex on trailing aircraft. During this investigation, two models of different scales were used to measure the aerodynamic forces and moments of the inboard wing configuration. The tests were conducted in the Virginia Tech 6X6 ft. wind tunnel using a six-component strain gauge balance. The Reynolds number based on chord for the small model was 465,000 and for the large model was 1,225,000. For reference, tests were also conducted with a plain wing having the same span as the full configuration. The L/D values found for this non-optimized configuration were modest compared to those for conventional transports. The vertical tails were shown to act as winglets, reducing drag and increasing L/D. These results suggest areas for substantial improvement in aerodynamic performance of the configuration. / Master of Science

Small scale unmanned aircraft, such as quadrotors, that are quickly emerging as versatile tools for a wide range of applications including search and rescue, hazardous environment exploration, or just shooting great video, are known as micro air vehicles (MAVs). However, for millimeter scale vehicles with weights under 10 grams, conventional flight technologies become greatly inefficient and instead inspiration is drawn from biology. Flapping wing MAVs (FWMAVs) have been created based on insects and hummingbirds in an effort to emulate their extreme agility and ability to hover in place. FWMAVs possess unique capabilities in terms of maneuverability, small size, and ability to operate in dynamic environments that make them particularly well suited for environmental monitoring and swarm applications such as artificial crop pollination. Despite their advantages, significant challenges in fabrication, power, and control must be overcome in order to make FWMAVs a reliable platform. Current designs suffer from high mechanical complexity and often rely on off-board power, sensing, and control, which compromises their autonomy and limits practical applications. The goal of my research is to develop a simple FWMAV design that provides high efficiency and controllability. An efficient, simple, and controllable vehicle design is developed utilizing the principles of resonance, emulation of biological flight control, and under-actuation. A highly efficient, resonant actuator is achieved by attaching a spring in parallel to the output shaft of a commercial geared DC micro-motor. This actuator directly drives the wings of the vehicle, allowing them to be controlled precisely and independently. This direct control strategy emulates biology and differs from other FWMAV designs that utilize complicated transmissions to generate flapping from rotary motor output. Direct control of the wings allows for emulation of biological wing kinematics, resulting in control based on wing motion alone. Furthermore, under-actuation is employed to mimic the rotational motion of insect wings. A rotational joint is added between the motor and wing membrane such that the wing rotates passively in response to aerodynamic forces that are generated as the wing is driven. This design is realized in several stages, initial prototyping, simulation and development of the actuator and wings, then finally a control system is developed. First the system was modeled and improved experimentally in order to achieve lift off. Improvements to the actuator were realized through component variation and custom fabrication increasing torque and power density by 161.1% and 666.8% respectively compared to the gearmotor alone and increased the resonant operating frequency of the vehicle from 4 Hz to 23 Hz. Advances in wing fabrication allowed for flexible wings that increased translational lift production by 35.3%, aerodynamic efficiency by 41.3%, and the effective lift coefficient by 63.7% with dynamic twisting. A robust control architecture was then developed iteratively based on a date driven system model in order to increase flight time from 1 second (10 wing strokes) to over 10 seconds (230 wing strokes). The resulting design improves lift to weight by 166%, allowing for a payload capacity of approximately 8.7 g and offers the potential for fully autonomous operation with all necessary components included on-board. A thermal model for micro-motors was developed and tuned to accurately predict an upper limit of system operation of 41 seconds as well as to optimize a heatsink that increases operating time by 102.4%.