Дисертації: "Airplanes – Motors – Design and construction"

1

Cranstone, Alexander William. "Low pressure turbine design for a future high bypass ratio aero-engine." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610530.

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2

Kay, Jacob. "Control authority assessment in aircraft conceptual design." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-03242009-040703/.

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3

Cabrera, Antonio Trani. "Combat aircraft scenario tradeoff models for conceptual design evaluation." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53920.

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The purpose of this research is to apply engineering-based knowledge to the field of combat aircraft survivability, and to create scenario-specific models in order to estimate the tradeoff between aircraft survivability and lethality metrics at the encounter and sortie levels. The development of scenario-specific models serves to identify and quantify technological changes that have Ieverage on the overall performance of the aircraft from a survivability point of view. Also, the models focus on the fighter aircraft susceptibility assessment and are capable of incorporating outputs from offline studies as inputs, such as in the area of vulnerability assessment where extensive databases are available. The mission scenario models are microscopic in nature and relate important conceptual aircraft design parameters such as thrust-to-mass ratio, wing loading, empty mass, maneuverability, etc. and operational parameters (e.g., weapon payload, range, loiter time, flight profiles, etc.) to the aircraft sortie survivability and lethality under various threat scenarios. This research proposes a methodology to estimate survivability and lethality aircraft performance at the sortie level where aircraft parameters can be implemented into scenario-specific models to assess their impact upon survivability-related metrics. While the project was conceived with naval aircraft in mind, the methodology, to the extent possible, is not to be aircraft-specific and thus could be applied to any particular design at the conceptual stage.
Ph. D.

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4

Martin, Benjamin C. "Geometric Design Optimization of Brushless Permanent Magnet Motors." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/MartinBC2009.pdf.

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5

Jimeno, Jesus. "A physics based robust methodology for aerodynamic design analysis and optimization." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/12472.

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6

Scharl, Julien. "Formulation and implementation of a methodology for dynamic modeling and simulation in early aerospace design." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/12973.

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7

Ellwood, Jeffrey L. "Design and construction of a composite airframe for UAV research." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA232422.

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Анотація:

Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, June 1990.
Thesis Advisor(s): Howard, Richard M. Second Reader: Lindsey, Gerald H. "June 1990." Description based on signature page as viewed on October 21, 2009. DTIC Identifier(s): Composite materials, ducted fan, airframes, vertical takeoff aircraft, remotely piloted vehicles. Author(s) subject terms: UAV, composites, AROD, TDF, RPV, ducted fan, vertical takeoff. Includes bibliographical references (p. 74-75). Also available online.

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8

Grieshaber, Michele Marie. "Interactive calculation of cross-sectional areas for aircraft design and analysis." Thesis, This resource online, 1988. http://scholar.lib.vt.edu/theses/available/etd-04272010-020357/.

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9

Yu, Chuang, and 余创. "Design, analysis and control of flux-mnemonic permanent magnet brushless machines." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44769027.

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10

Rohl, Peter Jurgen. "A multilevel decomposition procedure for the preliminary wing design of a high-speed civil transport aircraft." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/11827.

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11

Kelly, John H. "Rule-based fuselage and spine and cross-section methods for computer aided design of aircraft components." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06232009-063138/.

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12

Zhao, Gui Quan. "Design, control and experimental testing of intelligent variable dual-fuel automotive engines." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3691635.

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13

Niu, Shuangxia, and 牛双霞. "Design, control and application of double-stator permanent magnet brushless machines." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42841677.

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14

Liu, Chunhua, and 劉春華. "Design, analysis, control and application of permanent-magnet hybrid brushless machines." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42841665.

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15

Upton, Eric George. "An Intelligent, Robust Approach to Volumetric Aircraft Sizing." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16128.

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Анотація:

Advances in computational power have produced great strides in the later design and production portions of an aircraft s life cycle, and these advances have included the internal layout component of the design and manufacturing process. However, conceptual and preliminary design tools for internal layout remain primarily based on historical regressions and estimations a situation that becomes untenable when considering revolutionary designs or component technologies. Bringing internal layout information forward in the design process can encourage the same level of benefits enjoyed by other disciplines as advances in aerodynamics, structures and other fields propagate forward in the design of complex systems. Accurate prediction of the volume required to contain all of an aircraft s internal components results in a more accurate prediction of aircraft specifications, mission effectiveness, and costs, helping determine if an aircraft is the best choice for continued development. This is not a computationally simple problem, however, and great care must be taken to ensure the efficiency of any proposed solution. Any solution must also address the uncertainty inherent in describing internal components early in the design process. Implementing a methodology that applies notions of an intelligent search for a solution, as well as deals robustly with component sizing, produces a high chance of success. Development of a robust, rapid method for assessing the volumetric characteristics of an aircraft in the context of the conceptual and preliminary design processes can offer many of the benefits of a complete internal layout without the immense assignment of resources typical in the detail phase of the design process. A simplified methodology for volumetrically sizing an aircraft is presented here as well as an assessment of the state-of-the-art techniques for volumetric considerations used in current aircraft design literature. A prototype tool using a combination of original code and publicly available libraries is developed and explored. A sample aircraft design is undertaken with the prototype tool to demonstrate the effectiveness of the methodology.

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16

Soban, Danielle Suzanne. "A methodology for the probabalistic assessment of system effectiveness as applied to aircraft survivability and susceptibiliy." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/11739.

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17

Kim, Inn B. "Development and analysis of elastically tailored composite star shaped beam sections." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04062004-164703/unrestricted/kim%5Finn%5Fb%5F200312%5Fphd.pdf.

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18

Li, Fuhua, and 李富华. "Design, analysis, control and application of permanent magnet brushless dual-memory machines." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208621.

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Анотація:

Conventional PM machines have fixed PM excitation and can only perform flux-weakening by controlling the d-axis current. This current incurs the power dissipation and reduces the efficiency during flux-weakening operations. Memory machines change this situation by introducing the memory function, namely magnetizing or reversely magnetizing Al-Ni-Co PMs to change the air-gap flux density. This provides another new way to realizing flux-weakening. And the elimination of the flux-weakening d-axis current improves the overall efficiency. But the single-memory machines have lower power density due to the low-energy Al-Ni-Co PMs. By incorporating the memory concept and with the intention of improving the power density, the DC-excited PMBL dual-memory machines have been proposed and implemented, based on two kinds of PMs which are high-coercivity Nd-Fe-B PMs and low-coercivity Al-Ni-Co PMs. The Nd-Fe-B PMs provide a strong magnetic field to excite high air-gap flux density; while the Al-Ni-Co PMs can be forward magnetized to strengthen the magnetic field produced by Nd-Fe-B PMs or can be reversely magnetized to cancel that field. Consequently the air-gap flux density can be controlled within a wide range. A series of design principles on such kind of dual-memory machine are devised for guidance. The key design principles involve how to determine the number of salient poles on the stator and rotor, how to choose the surface areas and thicknesses of the two kind of PM pieces and how to size the rotor dimension. Generally, increase on the proportion of Nd-Fe-B PMs will raise the base field and the load capacity. On the other hand, increment on the proportion of Al-Ni-Co PMs will extend the controllable flux range. Analysis is also carried out on the equivalent magnetic circuit to formulate the magnetizing force exerted on Al-Ni-Co PMs. The machine model is analyzed by using time-stepping FEM (TS-FEM) and co-simulation of FEM software and Matlab Simulink. The dynamic reverse magnetizing processes are simulated and presented in details under different magnetizing current. In addition the effect of adding iron bridges between the two kinds PMs is also evaluated by simulations. Furthermore, the control methods are evaluate by simulations and experiments. The direct torque control (DTC) scheme is adapted to this doubly-salient dual-memory machine and a torque estimator is proposed to facilitate the DTC method. Both of the simulation results and the experimental results confirm the validity of the proposed design principles and the effectiveness of the control methods. Eventually, this dual-memory machine is proposed as a pole-changing wind power generator and a pole-changing EV machine. Simulation and experimental results have verified the validity of the pole-changing scheme and the pole-protection scheme.
published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy

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19

Gan, Jinyun, and 干金云. "Design, analysis and control of multiphase flux regulated permanent magnet brushless DC motor drives." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31245304.

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20

夏偉 and Wei Xia. "A new phase decoupling permanent magnet brushless DC motor and its control." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31235426.

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21

Kirby, Michelle Rene. "A methodology for technology identification, evaluation, and selection in conceptual and preliminary aircraft design." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/12042.

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22

Olafsson, Sveinn V. "Random vibrations of bladed-disk assembly under cyclostationary excitation." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43261.

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Random vibration of a bladed-disk assembly is studied. A stochastic model for the excitation is developed. A unique feature of this model is the statistical periodicity of the blade forces called cyclostationary. A random process is called wide sense eyeclostationary and its statistics are periodic in time. Factors like the turbulent nature of the flow around the blades, the variability in their geometry, and their nonuniform deterioration contribute to the uncertainty in the excitation. In periodic structures, like the bladed-disk assembly, small variation in the blade excitation may lead to high variability in the response. The model developed includes both random and deterministic excitation. A comparison of the responses due to the random and the deterministic part shows the significance of taking into account the variability in the blade forces. Therefore the assumption that the blade forces are all equal, used by all methods for vibration analysis of bladed disk assemblies, may lead to erroneous estimates of their response, reliability and expected life. It is shown that the response is a cyclostationary process. Therefore the cyclostationary property is preserved from the input to the output. Furthermore the frequency of the second moment of the response is equal to two times the frequency of the excitation.
Master of Science

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23

Dewitz, Michael B. "The effect of a fillet on a wing/body junction flow." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43843.

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24

Dayyani, Iman. "Mechanical behavior of composite corrugated structures for skin of morphing aircraft." Thesis, Swansea University, 2015. https://cronfa.swan.ac.uk/Record/cronfa42865.

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Corrugated panels have gained considerable popularity in a range of engineering applications, particularly in morphing skin applications due to their remarkable anisotropic characteristics. They are stiff to withstand the aerodynamic loads and flexible to enable the morphing deformations. In this thesis a detailed review of the literature on corrugated structures is presented. The specific characteristics of corrugated structures such as: high anisotropic behaviour, high stiffness and good durability, lightness and cost effectiveness are discussed comprehensively. However for the application in morphing aircraft, the optimal design of the corrugated panels requires simple models of these structures to be incorporated into multi-disciplinary system models. Therefore equivalent structural models are required that retain the dependence on the geometric parameters and material properties of the corrugated panels. In this regard, two analytical solutions based on homogenization and super element techniques are presented to calculate the equivalent mechanical properties of the corrugated skin. Different experimental and numerical models are investigated to verify the accuracy and efficiency of the presented equivalent models. The parametric studies of different corrugation shapes demonstrate the suitability of the proposed super element for application in further detailed design investigations. Then the design and multi-objective optimization of an elastomer coated composite corrugated skin for the camber morphing aerofoil is presented. The geometric parameters of the corrugated skin are optimized to minimize the in-plane stiffness and the weight of the skin and to maximize the flexural out-of-plane stiffness of the corrugated skin. A finite element code for thin beam elements is used with the aggregate Newton's method to optimize the geometric parameters of the coated corrugated panel. The advantages of the corrugated skin over the elastomer skin for the camber morphing structure are discussed. Moreover, a finite element simulation of the camber morphing internal structure with the corrugated skin is performed under typical aerodynamic and structural loadings to check the design approach.

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25

Strauch, Gregory J. "Integrated multi-disciplinary design of a sailplane wing." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45660.

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The objective of this research is to investigate the techniques and payoffs of integrated aircraft design. Lifting line theory and beam theory are used for the analysis of the aerodynamics and the structures of a composite sailplane wing. The wing is described by 33 - 34 design variables which involve the planform geometry, the twist distribution, and thicknesses of the spar caps, spar webs, and the skin at various stations along the wing. The wing design must satisfy 30 â 31 aeroelastic, structural, aerodynamic, and performance constraints.

Two design procedures are investigated. The first, referred to as the iterative, sequential procedure, involves optimizing the aerodynamic design for maximum average cross-country speed at E1 constant structural weight, and then optimizing the the structural design of the resulting wing geometry for minimum weight. This value is then used in another aerodynamic optimization, and the process continues iteratively until the weight converges. The other procedure, the integrated one, simultaneously optimizes the aerodynamic and the structural design variables for either maximum average cross-country speed or minimum weight.

The integrated procedure was able to improve the value of the objective function obtained by the iterative procedure in all cases. This shows The objective of this research is to investigate the techniques and payoffs of integrated aircraft design. Lifting line theory and beam theory are used for the analysis of the aerodynamics and the structures of a composite sailplane wing. The wing is described by 33 - 34 design variables which involve the planform geometry, the twist distribution, and thicknesses of the spar caps, spar webs, and the skin at various stations along the wing. The wing design must satisfy 30 â 31 aeroelastic, structural, aerodynamic, and performance constraints. Two design procedures are investigated. The first, referred to as the iterative, sequential procedure, involves optimizing the aerodynamic design for maximum average cross-country speed at E1 constant structural weight, and then optimizing the the structural design of the resulting wing geometry for minimum weight. This value is then used in another aerodynamic optimization, and the process continues iteratively until the weight converges. The other procedure, the integrated one, simultaneously optimizes the aerodynamic and the structural design variables for either maximum average cross-country speed or minimum weight.

The integrated procedure was able to improve the value of the objective function obtained by the iterative procedure in all cases. This shows that definite benefits can be gained from taking advantage of aerodynamic/structural interactions during the design process.

Master of Science

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26

Cheng, Ming, and 程明. "Design, analysis and control of doubly salient permanent magnet motor drives." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31241542.

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27

Malone, Brett. "Multidisciplinary optimization in aircraft design using analysis technology models." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10102009-020042/.

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28

Hines, Nathan Robert. "A probabilistic methodology for radar cross section prediction in conceptual aircraft design." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/12517.

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29

Kao, Pi-Jen. "Efficient methods for integrated structural-aerodynamic wing optimum design." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54211.

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The dissertation is focused on the large computational costs of integrated multidisciplinary design. Efficient techniques are developed to reduce the computational costs associated with integrated structural-aerodynamic design. First efficient methods for the calculations of the derivatives of the flexibility matrix and the aerodynamic influence coefficient matrix are developed. An adjoint method is used for the flexibility sensitivity, and a perturbation method is used for the aerodynamic sensitivity. Second a sequential optimization algorithm that employs approximate analysis methods is implemented. Finally, a modular sensitivity analysis, corresponding to the abstraction of a system as an assembly of interacting black boxes, is applied. This method was developed for calculating system sensitivity without modifying disciplinary black-box software packages. The modular approach permits the calculation of aeroelastic sensitivities without the expensive calculation of the derivatives of the flexibility matrix and the aerodynamic influence coefficient matrix.
Ph. D.

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30

DeLaurentis, Daniel A. "A probabilistic approach to aircraft design emphasizing stability and control uncertainties." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/12948.

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31

Arledge, Thomas K. "ACSYNT aerodynamic estimation : an examination and validation for use in conceptual design /." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-12052009-020129/.

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32

Marx, William J. "Integrating design and manufacturing for the high speed civil transport." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/12410.

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33

Collins, Edward Randolph Jr. "Torque and speed control of single-phase induction motors using an adjustable amplitude and phase angle auxiliary winding power supply." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/15472.

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34

Polen, David M. "Integrated aerodynamic-structural design of a subsonic, forward- swept transport wing." Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/46059.

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Анотація:

The introduction of composite materials and the ability to tailor these materials to improve aerodynamic and structural performance is having a distinct effect upon aircraft design. In order to optimize the efficiency of the design procedure, a design process which is more integrated than the traditional approach is required. Currently the utilization of such design procedures produces enormous computational costs. An ongoing effort to reduce these costs is the development of efficient methods for cross-disciplinary sensitivities and approximate optimization techniques.

The present research concentrates on investigating the integrated design optimization of a subsonic, forward-swept transport wing. A modular sensitivity approach for calculating the cross-sensitivity derivatives is employed. These derivatives are then used to guide the optimization process. The optimization process employed is an approximate technique due to the complexity of the analysis procedures. These optimization results are presented and the impact of the modular technique is discussed.

Master of Science

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35

Ippolito, Corey A. "Software architectures for flight simulation." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/15749.

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36

Unger, Eric Robert. "Computational aspects of the integrated multi-disciplinary design of a transport wing." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/42125.

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Past research at this university has proven the feasibility of the multi-disciplinary design of a complex system involving the complete interaction of aerodynamics and structural mechanics. Critical to this design process, is the ability to accurately and efficiently calculate the sensitivities of the involved quantities (such as drag and dynamic pressure) with respect to the design variables. These calculations had been addressed in past research, but it was felt that insufficient accuracy had been obtained. The focus of this research was to improve the accuracy of these sensitivity calculations with a thorough investigation of the computational aspects of the problem. These studies led to a more complete understanding of the source of the errors that plagued previous results and provided substantially improved sensitivity calculations. Additional research led to an improvement in the aerodynamic-structural interface which aided in the accuracy of the sensitivity computations. Furthermore, this new interface removed discontinuities in the calculation of the drag which the previous model tended to yield. These improvements were made possible with the application of shape functions in surface deflection analysis, instead of the previous ‘zonal’ approach. Other factors which led to accuracy improvements were changes to the aerodynamic model and the paneling scheme. Final studies with the optimization process demonstrated the ability of the improved sensitivities to accurately approximate the design problem and provided useful results. Additional studies on the optimization process itself provided information on move limit restrictions and various constraint problems.
Master of Science

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37

Harman, Alex Bruce Mechanical &amp Manufacturing Engineering Faculty of Engineering UNSW. "Optimisation and improvement of the design of scarf repairs to aircraft." Awarded by:University of New South Wales. School of Mechanical and Manufacturing Engineering, 2006. http://handle.unsw.edu.au/1959.4/26788.

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Flush repairs to military aircraft are expected to become more prevalent as more thick skin composites are used, particularly on the surface of the fuselage, wings and other external surfaces. The use of these repairs, whilst difficult to manufacture provide an aerodynamic, ???stealthy??? finish that is also more structurally efficient than overlap repairs. This research was undertaken to improve the design methodology of scarf repairs with reduced material removal and to investigate the damage tolerance of scarf repair to low velocity impact damage. Scarf repairs involve shallow bevel angles to ensure the shear stress in the adhesive does not exceed allowable strength. This is important when repairing structures that need to withstand hot and humid conditions, when the adhesive properties degrade. Therefore, considerable amounts of parent material must be machined away prior to repair. The tips of the repair patch and the parent laminate are very sharp, thus a scarf repair is susceptible to accidental damage. The original contributions include: ??? Developed analytic means of predicting the stresses within optimised scarf joints with dissimilar materials. New equations were developed and solved using numerical algorithms. ??? Verified using finite element modelling that a scarfed insert with dissimilar modulus subjected to uniaxial loading attracted the same amount of load as an insert without a scarf. As such, the simple analytic formula used to predict load attraction/diversion through a plate with an insert may be used to predict the load attraction/diversion into a scarf repair that contains a dissimilar adherend patch. ??? Developed a more efficient flush joint with a doubler insert placed near the mid line of the parent structure material. This joint configuration has a lower load eccentricity than external doubler joint. ??? Investigated the damage tolerance of scarf joints, with and without the external doubler. The results showed that scarf joints without external doublers exhibited a considerable strength reduction following low velocity impact. Based on the observations, the major damage mechanics in the scarf joint region following impact have been identified. These results demonstrated that it is important to incorporate damage tolerance in the design of scarf repairs.

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38

Han, Lin 1982. "A comparison of permanent magnet motor structures for traction drive applications in hybrid electric vehicles /." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116015.

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This thesis presents a detailed comparison of the torque-speed characteristics of three permanent magnet synchronous machine designs based on how the magnets are mounted. The machines investigated are an interior permanent magnet machine, an interior-rotor surface-mounted machine and an exterior-rotor surface-mounted machine. They are designed for traction drives in hybrid electric vehicles. Two sets of comparisons based on the same machine volume and starting torque are performed. Important issues, such as machine mass and cost, cogging torque, and flux-weakening capability are addressed. Computer simulations were performed to estimate their performances and the results are presented. Design guidelines and tradeoffs of their performances are extracted from the simulation results. Relative strengths and limitations of different PM machine types are highlighted.

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39

Nafziger, John S. "Reverse parameterization of B-spline surfaces for data transfer." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06302009-040414/.

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40

Papay, Michael L. "A general inverse design procedure for aerodynamic bodies." Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/38556.

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41

Huang, Ximing. "Structural optimization and its interaction with aerodynamic optimization for a high speed civil transport wing." Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/40132.

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A variable-complexity design strategy with combined aerodynamic and structural optimization procedures is presented for the high speed civil transport design (HSCT). Variable-complexity analysis methods are used to reduce the computational expense. A finite element-model based structural optimization procedure with flexible loads is implemented to evaluate the wing bending material weight. Static aeroelastic effects, evaluated through the comparison of rigid and flexible wing models, are found to be small in the HSCT design. The results of structural optimization are compared with two quasi-empirical weight equations. Good correlation is obtained between the structural optimization and one of the weight equations. Based on this comparison, an interlacing procedure is developed to combine both the simple weight equations and structural optimization in the HSCT design optimization, at modest computational cost. HSCT designs based on the interlacing procedure reveal that the aerodynamic optimizer may take advantage of weaknesses in weight equation. However, the optimizer may be unable to escape the local minimum due to the noisy of aerodynamic response and the lack of derivative information for the interlacing procedure.
Ph. D.

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42

Patil, Mayuresh J. "Nonlinear aeroelastic analysis, flight dynamics, and control of a complete aircraft." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/12099.

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43

Zhang, Haochuan. "Nonlinear aeroelastic effects in damaged composite aerospace structures." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/12150.

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44

Jones, Robert W. "Intersection and filleting of non-uniform B-spline surfaces." Thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/42189.

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Анотація:

Preliminary aircraft design codes requIre a more complete and integrated geometry definition than that used by conceptual design codes. This thesis documents the design and creation of an interactive CAD system which converts the geometry descriptions commonly used in conceptual aircraft design codes to descriptions that meet the requirements of preliminary design systems. In particular, the conversion of ACSYNT Hermite surface data of aircraft models to the non-uniform hi-cubic B-Spline surface representation is addressed. The topics discussed in this thesis include the design and development of an interactive graphics user interface, the design and coding of an intersection method for non-uniform hi-cubic B-Spline surfaces utilizing subdivision techniques and the development of a one-dimensional filleting algorithm for blending surfaces along iso-parametric curves.
Master of Science

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45

Hall, Neil Scott. "Impact of data modeling and database implementation methods on the optimization of conceptual aircraft design." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/16847.

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46

Bryant, David. "Design and prototyping of an aircraft to maximize the triaviation score." University of Western Australia. School of Mechanical Engineering, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0113.

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This thesis describes some of the processes and results obtained during the design and prototyping of a single seat experimental aircraft. The major aim was to maximise the Triaviation score of the aircraft. This score is a combination of the top speed, the stall speed and the rate of climb. The aircraft has been designed constructed, inspected and flown. The process of designing and prototyping is outlined in this thesis. Details are provided regarding preliminary design, numerical optimisation and the process of building the prototype. The aircraft registered VH-ZYY is a shoulder wing monoplane using a Continental IO-240 aircraft engine. The aircraft has a high power to weight ratio and light wing loading to assist it to climb well and fly slowly. Full span flaperons are used to increase the maximum coefficient of lift at the stall. The primary structure is aluminium with a carbon fibre and nomex cored cowl. All steel components have been formed with 4130 chrome molybdenum aircraft grade tubing. All hardware uses AN specification parts. VH-ZYY is registered in Australia as an Experimental aircraft.

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47

Ajaj, Rafic Mohammad. "Design, modelling and optimisation of morphing structures for medium altitude long endurance UAVs." Thesis, Swansea University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678283.

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48

Hasan, Shahab. "An object-oriented, PHIGS-based Internal Layout Module for aircraft design." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-03032009-040349/.

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49

Arnold, David Patrick. "Magnetic Machines for Microengine Power Generation." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4854.

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This dissertation presents an investigation of miniaturized magnetic induction and permanent magnet (PM) machines, intended for use in a microengine. Similar to a macroscale turbogenerator, a microengine comprises a small, gas-fueled turbine engine for converting chemical fuel energy into mechanical power and an integrated electrical generator for converting mechanical power to electrical power. The microengine system is proposed as a revolutionary, high power-density source for portable electronics. In this research, miniaturized magnetic induction machines and PM machines were designed, fabricated, and characterized. Both types of machines used axially directed magnetic fields and were nominally 10 mm in diameter and 1.5-2.3 mm in thickness. Innovative microfabrication techniques were developed to demonstrate the feasibility of integrating magnetic machines within a bulk-micromachined, silicon-based microengine system. Two-phase, eight-pole induction machines were constructed within silicon substrates using Cu coils in a laminated, slotted ferromagnetic NiFe or CoFeNi stator core. Silicon etching, wafer bonding, and electrodeposition were used to form all of the magnetic machine components. The induction machines were characterized in motoring mode using tethered rotors and demonstrated motoring torques of up to 2.5 uN-m. Also, three-phase, eight-pole, surface wound PM machines were built using a hybrid microfabrication/assembly approach. The stators were fabricated by electroplating Cu coils on ferromagnetic NiFeMo (Moly Permalloy) substrates. The rotors were formed by assembling a magnetically patterned SmCo PM with a FeCoV (Hiperco 50) back iron. The PM machines were tested as generators with free-spinning rotors, powered by an air-driven spindle, and demonstrated 2.6 W of mechanical-to-electrical power conversion with continuous DC power generation of 1.1 W at 120 krpm rotor speed. The primary contributions of this work are (1) the demonstration of microfabricated magnetic machines integrated within bulk-micromachined silicon and (2) the demonstration of multi-watt power conversion from a microfabricated PM generator. These achievements represent progress in the ongoing development of silicon-based microengines, but in addition, the fabrication technologies and device structures may find application in other microsystems.

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50

Legesse, Michael. "Coupled simulation of an indirect field oriented controlled induction motor drive." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116014.

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Conventionally, system simulations of induction motor drives use lumped parameters model of the motor. This approach assumes motor parameters to be constant during the entire operation of the drive. Unfortunately, these are known to vary significantly over the operating range of the motor due to factors such as magnetic saturation, skin effects, and operating temperature. The variations in motor parameters affect motor output and control parameters resulting in degraded drive performance. One way of overcoming this problem is by coupling the field model of the induction motor with the drive simulation. By replacing the lumped parameters model with the field model, the influence of different operating conditions on motor parameters can be taken into account dynamically. In this thesis such an approach is investigated by coupling the finite element analysis of an induction motor with the system simulation of the field oriented controlled drive. The results obtained for the coupled simulation are promising and possible future works to make this method of simulation more accurate and reliable are recommended.

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Дисертації з теми "Airplanes – Motors – Design and construction"

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