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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design and safety analysis of an in-flight, test airfoil

McKnight, Christopher William 30 October 2006 (has links)
The evaluation of an in-flight airfoil model requires extensive analysis of a variety of structural systems. Determining the safety of the design is a unique task dependant on the aircraft, flight environment, and physical requirements of the airfoil. With some areas of aerodynamic research choosing to utilize flight testing over wind tunnels the need to design and certify safe and reliable designs is a necessity. Commercially available codes have routinely demonstrated an ability to simulate complex systems. The union of three-dimensional design software with finite element programs, such as SolidWorks and COSMOSWorks, allows for a streamlined approach to the iterative task of design and simulation. The iterative process is essential to the safety analysis of the system. Results from finite-element analysis are used to determine material selection and component dimensions. These changes, in turn, produce different stress profiles, which will affect other components. The unique case presented in this study outlines the process required to certify a large swept-wing model mounted to a Cessna O-2 aircraft. The process studies the affect of aerodynamic loading on the hard-point structure inside the wing, as well as the model mounting structure, and support strut. The process does not end when numerical simulations indicate that each system is safe. Following numerical work, a series of static tests are used to verify that no unforeseen failures will occur. Although the process is tailored to one specific example, it outlines an approach that could be applied to any test platform. A different model may create a physically different system, but the safety analysis would remain the same.
2

The design and construction of a shiplaunched VTOL unmanned air vehicle

Blanchette, Bryan M. January 1990 (has links) (PDF)
Thesis (M.S. in Engineering Science)--Naval Postgraduate School, June 1990. / Thesis Advisor(s): Howard, Richard M. Second Reader:Pagenkopf, Eric L. "June 1990." Description based on title screen as viewed on October 19, 2009. DTIC Descriptor(s): Remotely piloted vehicles, vertical takeoff aircraft, ducted fans, velocity, flight testing, measurement, recovery, aircraft, hazards, demonstrations, fabrication, cycles, flight, vertical orientation, test vehicles, unmanned, safety, takeoff, shipboard, engines, reinforced plastics, propeller blades, propellers, static tests, tilt, thrust, horizontal orientation DTIC Indicator(s): UAV (Unmanned Air Vehicles), tilt, ship launched, shrouded propellers, aeronautical engineering, archytas aircraft, model tests. Author(s) subject terms: Unmanned Air Vehicle (UAV), Vertical Takeoff and Landing (VTOL), ducted fan, Remotely Piloted Vehicle (RPV) Includes bibliographical references (p. 93-94). Also available in print.
3

HIGH ALTITUDE TRANSMITTER FLIGHT TESTING

Brown, K. D., Sorensen, Trevor 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / This paper describes a high altitude experimental flight test platform developed by the University of Kansas (KU) and the National Nuclear Security Administration’s Kansas City Plant (NNSA’s Kansas City Plant) for high altitude payload flight testing. This platform is called the Kansas University Balloon Experiment Satellite (KUBESat). The paper describes the flight test platform and experimental flight test results captured at Fort Riley, KS from characterization of the KCP developed Distributed Transmitter (DTX).
4

GPS-Trak Low Cost Alternative to Auto-Tracking Using GPS and Multimode Single Axis Antenna Techniques

Sullivan, Arthur 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / The GPS Satellite System provides precise determination of time, space, and position of aerospace (airborne) vehicles during flight and flight test situations. The cost of "GPS" equipment has been decreasing dramatically -- a phenomenon similar to that which was experienced with "hand held" calculators 20 years or so ago. By the use of a multigain (and beam) antenna and GPS, a very low cost single axis system can be utilized for reception of telemetry and at the same time to provide accurate position, velocity, and acceleration information concerning the airborne vehicle.
5

Project Solaris – Construction of Solar Powered UAV Prototype

Johansson, Magnus January 2011 (has links)
Abstract To control an un-swept flying wing is problematic in some ways. One of the problems is that when the wing experiences a disturbance in yaw, it does not, since it has no tail, generate any torque in the opposite direction as a plane with a vertical stabilizer does. This thesis is foremost aimed at exploring one particular solution to this problem. One approach to this problem is to place the motors out on the wing and differentiate the thrust, to achieve the same torque as splitted elevons or a vertical stabilizer does. This is what NASA used on the flying unmanned wing HELIOS. Reducing the thrust on the right set of engines, and increasing the thrust on the left side can mean that the combined thrust is unchanged. And thus more fuel efficient, and increases endurance. This project’s main goal has been to construct a half scale model of the school project flying wing Solaris, and to configure a control system for the differentiated thrust as used on Helios. Thereafter conduct flight testing and evaluate the controllability of the wing in a number of flight conditions, this to get a sense of the wings characteristics and which parameters one should adjust to get the best controllability as possible. After numerous adjustments and test flights it was concluded that it is possible to construct and fly a wing in this configuration, with relatively simple means, with satisfactory results. That the torsional rigidity has great influence on the controllability were evident after the test flights. After redistribution of the components on the wing the conclusion could be made that the dihedral could be held within the structural limit of the wing. The results of this thesis will contribute to the project Solaris at Mälardalens University in Västerås, Sweden. The project was carried out at Mälardalens University. The test flights were conducted at the former Air Force base F-15 Flygstaden and Mohed in Söderhamn, Hälsingland. / Solaris
6

Development of a full potential solver for rotor aerodynamics analysis

Prichard, Devon S. 05 1900 (has links)
No description available.
7

Advanced integrated helicopter flight simulator cockpit design

Elias, Joerg 08 1900 (has links)
No description available.
8

A helicopter flight path controller design via a nonlinear transformation technique

Heiges, Michael W. 05 1900 (has links)
No description available.
9

Application of approximation techniques to helicopter flight path optimization

Boen, Gilbert E. 05 1900 (has links)
No description available.
10

Study of Rubber Damped Skin Friction Gages for Transonic Flight Testing

Sang, Alexander Kipkosgei 25 July 2001 (has links)
A non-intrusive direct-measuring skin friction device with a rubber RTV sheet over the surface of the floating head, gap and housing was developed for application in 3D, unsteady, transonic flight conditions. Design conditions required optimum gage performance at altitudes ranging from 15,000 to 45,000 feet, Mach numbers ranging from 0.6 to 0.99 resulting in shear values of 0.3 to 1.5 psf. under vibration conditions up to 8.0 grms over a 15 - 2,000 Hz frequency range. The gage consisted of a rubber RTV sheet-coated floating element attached to an aluminum cantilevered beam. A dual-axis, full bridge strain gage configuration was used with the application of semi-conductor strain gages to increase instrument sensitivity. The gage was studied with and without a viscous liquid (glycerin) fill in the housing. Vibration verification testing was performed at 1.0 grms in the Virginia Tech modal analysis lab to ensure adequate damping performance over a 0−3200 Hz frequency range. Tests revealed that the rubber RTV compound sheet provided adequate viscoelastic damping, with or without viscous liquid fill. Gage performance verification testing was performed on in the Virginia Tech supersonic wind tunnel at shear levels of tw = 3.9 to 5.3 psf in a Mach 2.4 flow. Skin friction values in good agreement with previous testing and analytical predictions were obtained from the tests with adequate damping in the low vibration environment of the Virginia Tech supersonic wind tunnel. The gage proved robust as it survived repeated runs including the violent start and unstart processes typical of a supersonic, blowdown wind tunnel. Flight tests were performed at NASA Dryden Flight Research Center, with the gage mounted in a plate suspended below an F-15 aircraft. This provided a mildly 3D, turbulent boundary layer on a vibrating surface. The gage was tested without liquid fill in the gage cavity, and it performed satisfactorily in this high vibration environment. The gage demonstrated adequate damping and good robustness, surviving the complete flight test intact and remained fully operational. The sensor measured skin friction values 30%-50% higher than those predicted by indirect methods and analogies generally valid for 2D, steady flows. The gage indicated trends in skin friction values for different flight conditions in good agreement with the other methods. Possible reasons for the differences in numerical values are discussed in detail, including potential uncertainties in the gage output and limitations and uncertainties in the methods used for comparison. Finally, suggestions for further development of such gages are provided for flight test applications. / Master of Science

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