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1
Chopra, Shubh. "Development of mobile applications for crop scouting with small unmanned aircraft systems." Kansas State University, 2017. http://hdl.handle.net/2097/35507.
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Master of ScienceDepartment of Computer Science
Antonio R. Asebedo
Mitchell L. Neilsen
Small unmanned aircraft systems (sUAS) have been in commercial use since the1980’s and over 8-12% of its current uses are in the agricultural sector, but only involving limited uses like surveying, mapping and imaging, which is expected to increase to 47% according to AUVSI with the association of Artificial Intelligence over the next decade. Our research is one such effort to help farmers utilize advanced sUAS technology coupled with Artificial Intelligence and give them meaningful results in a widely used and user friendly interface, like a mobile application. The vision for this application is to provide a completely automated experience to the farmer for a repetitive and periodic analysis of his/her crops where all the instruction needed from the farmer is a push of a button on a one time configured application and ultimately providing results in seconds. This would help the farmer scout their crops, assess yield potential, and determine if additional inputs are needed for increasing grain yield and profit per acre. For making this application we focused on user-friendliness by abstracting crop algorithms, minimized necessary user inputs, and automate the construction of flight paths. Due to internet connection not always being available at farm fields, processing was kept to on-board compute systems and the mobile device to give live results to farmers without reliance on cloud-based analytics. The application is configured to work with DJI Aircraft using OpenCv for video processing and mobile vision, GIS and GPS data for accurate mapping, locating device, sUAS on the mobile application, and FFMPEG for encoding and decoding compressed video data. An algorithm developed by Precision-Ag Lab at the K-State Agronomy Department was implemented into the sUAS application for providing real time yield estimations and nitrogen recommendation algorithm for winter wheat.
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Simpson, Mark N. "The application of semi-active control technology to aircraft landing gear." Thesis, Loughborough University, 1988. https://dspace.lboro.ac.uk/2134/6764.
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The purpose of the research investigation was to study the application of semi-active control technology to the design of a suspension system to be used in a landing gear of a high speed military aircraft. A semi-active system was used because it will allow a system to be driven from the hydraulic systems already existing in the aircraft without extensive modification. The research work involved establishing a theoretical mathematical model for the semi-active damping system. This model involved a large number of non-linear dynamic phenomena and elements including a two-stage gas spring, lever geometry, break out friction, square law damping and the switching function needed to achieve the semi-active control. Validation of the model was carried out by means of an extensive study of the dynamic responses obtained from digital simulation. An extended programme of laboratory experiments was also carried out to confirm the theoretical and simulated results, and to demonstrate the potential benefits in performance which can be achieved with those obtained from standard and optimized passive suspension system. The experimental rig involved a physical model which used hydraulic elements of a general industry standard, but not specially approved for aircraft use. The apparatus was arranged to permit a considerable degree of freedom for implementing the control laws which facilitated the assessment of different control schemes and allowed, at the same time, the ready simulation of various passive damping arrangements. An extensive series of trials was carried out on the final design and involved frequency response tests and subjecting the experimental suspension to inputs obtained from a simulated runway profile. The profile simulation was a discrete representation of a particular runway chosen for its roughness which was characteristic of runways from which high-speed military aircraft operate. From the research investigation and these trials it was established that semi-active control of the damping function is superior to standard techniques and achieves a substantial reduction in the energy transmitted to the airframe during ground manoeuvres.
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Hyde, Richard Alden. "The application of robust control to VSTOL aircraft." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333330.
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Gill, Simon Adrain. "Application of human factors methodologies to aircraft maintainability." Thesis, University of Nottingham, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.537824.
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Plastow, Ian. "The development and application of computational methods for the design of aircraft fuel systems." Thesis, University of Bristol, 1994. http://hdl.handle.net/1983/1889c413-8033-41e3-8058-0c8f6e54bdf6.
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Maharaj, Davendra Yukteshwar. "The application of nonlinear control theory to robust helicopter flight control." Thesis, Imperial College London, 1994. http://hdl.handle.net/10044/1/7420.
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Bergkvist, Erik, and Tommy Sabbagh. "Smart Future Solutions for Maintenance of Aircraft : Enhancing Aircraft Maintenance at Saab AB." Thesis, Linköpings universitet, Industriell Produktion, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-176561.
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This master thesis has the purpose to analyse and identify smart efficient future solutions within the Maintenance, Repair and Overhaul (MRO) process for aircraft. The efficiency solutions, in form of new technologies and tools, should present a foundation that MRO suppliers can continue to develop to enhance and streamline their maintenance processes. The project was performed as a case study at the aerospace and defense company Saab AB in Linköping, where the company's MRO process was investigated. Through identifying possibilities and alternative technologies available today and in the near future, one continues to have a competitive and future-proof position in the market. Through an own constructed course of action influenced from established methods, the thesis' purpose and aim was attained. The method was based on authentic approaches for case studies but also inspired by the so-called "Requirement Engineering". The combination of the methods resulted in a precise focus on the relevant subjects, together with a clear structure of the requirements on the technologies to reach a successful implementation. Through a detailed data collection comprised of study visits, interviews, literature studies, market analyses, and document reviews, multiple relevant technologies and requirement-lists for utilization were identified. To concretize the use and potential improvements with the technologies, the project had the objective to develop a demonstrator with one of the technologies presented. The demonstrator should focus on minimizing the use of paper, which is a common problem among many market actors today. The most promising technology was considered to be a tablet application with an accommodated application. The selection of the tablet solution was based on the motivation that it is a well-established technology and a favorable first step from paperwork. To conclude this master thesis, a tablet application was developed in Novacura Flow Studio, where the majority of the identified requirements were fulfilled. Beyond the demonstrator, an introduction and analysis of technologies, such as AR-glasses, voice guidance, additive manufacturing, and a digital twin, was presented.
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Dudgeon, Graham John William. "Individual channel analysis and design and its application to helicopter flight control." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325388.
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Bingham, Christopher Malcolm. "Application of variable structure control methods to actuator nonlinearities in aerospace systems." Thesis, Cranfield University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358823.
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Brown, Mark Anthony. "An investigation of three-dimensional displays for real-time, safety-critical command/control applications : with application to air traffic control." Thesis, Queen Mary, University of London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336445.
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Edi, Prasetyo. "Investigation of the application of hybrid laminar flow control and variable chamber wing design for regional aircraft." Thesis, Cranfield University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266979.
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Rolston, Stephen Carson. "An application of passive control for supersonic sidewall intakes." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359123.
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Lowenberg, Mark H. "Application of bifurcation analysis to multiple attractor flight dynamics." Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264065.
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Gao, Fei. "Continuing airworthiness policy and application to flying crane aircraft." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/5634.
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This project is part of a collaborative MSc training programme between the
Aviation Industries of China (AVIC) and Cranfield University, aiming at
enhancing the competitiveness of AVIC in both international and domestic
aviation market through applying continuing airworthiness policies in the whole
aircraft development process.
The arrangement of the research project is that all students start with a Group
Design Project which is based on the Flying Crane Project provided by AVIC.
Individual research projects will address some aspects of the Flying Crane
Project during the Group Design Project, and then further developed during the
period for individual projects. The aim of this research is to apply the
airworthiness requirements and the methodology of the Maintenance Steering
Group logic (MSG-3) in the Flying Crane Project. This is because that
maintenance is one of the key factors of Continuing Airworthiness, and MSG-3
logic is the most accepted and approved method to develop scheduled
maintenance for civil aircrafts.
The main objectives of this project include: (1) To investigate current Continuing
Airworthiness regulations, including European airworthiness requirements (as
the main regulation to comply with) and Chinese airworthiness regulations (as
an important reference and supplement to the research); (2) To investigate the
main analysis methodology of reliability and maintainability, including Damage
Tolerance and Failure Mode and Effect Analysis (FMEA); (3) To analyse the
data resulted from the Group Design Project using MSG-3 logic to produce a set
of Continuing Airworthiness instructions, for the operator and maintenance
organisation of the aircraft, from the design organization’s perspective; (4) To
develop Continuing Airworthiness instructions for airline operators to compose
maintenance programmes for Flying Crane aircrafts, including maintenance
tasks and intervals for the selected airframe systems and structural components;
and (5) To identify applicable maintenance organisations in China for Flying
Crane aircrafts in accordance with both European and Chinese airworthiness
requirements.
On completion of this research, two aspects of Continuing Airworthiness have
been investigated, including maintenance programme and maintenance
organization. With MSG-3 logic, the author developed the maintenance plan for
three structural components (fuselage skin panel, wing root joint, and
fin-fuselage attachment) and one airframe system (fuel system) based on results
from the Group Design Project. The author also investigated the Chinese
domestic aircraft maintenance companies, and selected suitable maintenance
organizations based on technical and economical criteria.
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Meo, Michele. "Application of welding to a large civil aircraft wing." Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323959.
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Chu, Liu. "Reliability and optimization, application to safety of aircraft structures." Thesis, Rouen, INSA, 2016. http://www.theses.fr/2016ISAM0008/document.
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Les chercheurs dans le domaine de la conception aérodynamique et de la fabrication des avions ont fait beaucoup d'effort pour améliorer les performances des ailes par des techniques d'optimisation. Le développement de la mécanique des fluides numérique a permis de réduire les dépenses en soufflerie tout en fournissant des résultats convaincants pour simuler des situations compliquées des aéronefs. Dans cette thèse, il a été choisi une partie spéciale et importante de l'avion, à savoir, la structure de l'aile. L'optimisation basée sur la fiabilité est une méthode plus appropriée pour les structures sous incertitudes. Il se bat pour obtenir le meilleur compromis entre le coût et la sécurité tout en tenant compte des incertitudes du système en intégrant des mesures de fiabilité au sein de l'optimisation. Malgré les avantages de l'optimisation de la fiabilité en fonction, son application à un problème d'ingénierie pratique est encore assez difficile. Dans notre travail, l'analyse de l'incertitude dans la simulation numérique est introduite et exprimée par la théorie des probabilités. La simulation de Monte Carlo comme une méthode efficace pour propager les incertitudes dans le modèle d'éléments finis de la structure est ici appliquée pour simuler les situations compliquées qui peuvent se produire. Pour améliorer l'efficacité de la simulation Monte Carlo dans le processus d'échantillonnage, la méthode de l'Hypercube Latin est effectuée. Cependant, l'énorme base de données de l'échantillonnage rend difficile le fait de fournir une évaluation explicite de la fiabilité. L'expansion polynôme du chaos est présentée et discutée. Le modèle de Kriging comme un modèle de substitution joue un rôle important dans l'analyse de la fiabilité. Les méthodes traditionnelles d'optimisation ont des inconvénients à cause du temps de calcul trop long ou de tomber dans un minimum local causant une convergence prématurée. Le recuit simulé est une méthode heuristique basée sur une recherche locale, les Algorithmes Génétiques puisent leur inspiration dans les principes et les mécanismes de la sélection naturelle, qui nous rendent capables d'échapper aux pièges des optimums locaux. Dans l'optimisation de la conception de base de la fiabilité, ces deux méthodes ont été mises en place comme procédure d'optimisation. La boucle de l'analyse de fiabilité est testée sur le modèle de substitutionTremendous struggles of researchers in the field of aerodynamic design and aircraft production were made to improve wing airfoil by optimization techniques. The development of computational fluid dynamic (CFD) in computer simulation cuts the expense of aerodynamic experiment while provides convincing results to simulate complicated situation of aircraft. In our work, we chose a special and important part of aircraft, namely, the structure of wing.Reliability based optimization is one of the most appropriate methods for structural design under uncertainties. It struggles to seek for the best compromise between cost and safety while considering system uncertainties by incorporating reliability measures within the optimization. Despite the advantages of reliability based optimization, its application to practical engineering problem is still quite challenging. In our work, uncertainty analysis in numerical simulation is introduced and expressed by probability theory. Monte Carlo simulation as an effective method to propagate the uncertainties in the finite element model of structure is applied to simulate the complicate situations that may occur. To improve efficiency of Monte Carlo simulation in sampling process, Latin Hypercube sampling is performed. However, the huge database of sampling is difficult to provide explicit evaluation of reliability. Polynomial chaos expansion is presented and discussed. Kriging model as a surrogate model play an important role in the reliability analysis.Traditional methods of optimization have disadvantages in unacceptable time-complexity or natural drawbacks of premature convergence because of finding the nearest local optima of low quality. Simulated Annealing is a local search-based heuristic, Genetic Algorithm draws inspiration from the principles and mechanisms of natural selection, that makes us capable of escaping from being trapped into a local optimum. In reliability based design optimization, these two methods were performed as the procedure of optimization. The loop of reliability analysis is running in surrogate model
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Türkoglu, Ercüment. "Application of robust control to a rotary-wing aircraft." Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/30248.
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The thesis is concerned with the application of robust controller synthesis and analysis tools to a rotary-wing aircraft: the Bell 205 teetering-rotor helicopter. The Tioo loop-shaping approach is central to the work and two main issues concerned with its application will be considered. Firstly, the construction of diagonal (structured) and non- diagonal (unstructured) weighting functions will be considered. Secondly, the analysis of the implications of different weighting function structures in the controller implementation. A two stage cross-comparative analysis of a series of 1 Dof (Degree of Freedom) and 2 Dof controllers synthesized with both diagonal and non-diagonal weights using the Hqo loop- shaping technique will be presented for square and non-square multi input multi output, unstable, non-minimum phase and ill-conditioned models of the helicopter. Handling qualities of each control law augmented system will be assessed quantitatively and qualitatively. A quantitative analysis, in view of the specifications in ADS-33E, will be given based on a combination of flight data from in-flight tested controllers and, desk-top simula tions run on a fully augmented 12 Dof nonlinear helicopter model provided by QinetiQ, UK. A qualitative analysis will be given based on the pilot comments compiled (in view of the Cooper-Harper handling qualities rating scale) from the evaluated in-flight control laws.
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Simon, Daniel. "Fighter Aircraft Maneuver Limiting Using MPC : Theory and Application." Doctoral thesis, Linköpings universitet, Reglerteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-139945.
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Flight control design for modern fighter aircraft is a challenging task. Aircraft are dynamical systems, which naturally contain a variety of constraints and nonlinearities such as, e.g., maximum permissible load factor, angle of attack and control surface deflections. Taking these limitations into account in the design of control systems is becoming increasingly important as the performance and complexity of the aircraft is constantly increasing. The aeronautical industry has traditionally applied feedforward, anti-windup or similar techniques and different ad hoc engineering solutions to handle constraints on the aircraft. However these approaches often rely on engineering experience and insight rather than a theoretical foundation, and can often require a tremendous amount of time to tune. In this thesis we investigate model predictive control as an alternative design tool to handle the constraints that arises in the flight control design. We derive a simple reference tracking MPC algorithm for linear systems that build on the dual mode formulation with guaranteed stability and low complexity suitable for implementation in real time safety critical systems. To reduce the computational burden of nonlinear model predictive control we propose a method to handle the nonlinear constraints, using a set of dynamically generated local inner polytopic approximations. The main benefit of the proposed method is that while computationally cheap it still can guarantee recursive feasibility and convergence. An alternative to deriving MPC algorithms with guaranteed stability properties is to analyze the closed loop stability, post design. Here we focus on deriving a tool based on Mixed Integer Linear Programming for analysis of the closed loop stability and robust stability of linear systems controlled with MPC controllers. To test the performance of model predictive control for a real world example we design and implement a standard MPC controller in the development simulator for the JAS 39 Gripen aircraft at Saab Aeronautics. This part of the thesis focuses on practical and tuning aspects of designing MPC controllers for fighter aircraft. Finally we have compared the MPC design with an alternative approach to maneuver limiting using a command governor.
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Bennett, David. "The application of robust inverse dynamics estimation to the control of V/STOL aircraft." Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387648.
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Pozsar, Michael John. "Application of the lean aircraft initiative factory operations model to case studies in the defense aircraft industry." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10966.
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Faleiro, Lester F. "The application of eigenstructure assignment to the design of flight control systems." Thesis, Loughborough University, 1998. https://dspace.lboro.ac.uk/2134/7083.
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Modem control methods have often been advocated by academics as able to solve fairly complex control engineering design problems in the aircraft industry. However, evidence suggests that practicei s still gearedt owardsu sing classicalt echniques,e ven on the most modem fighter aircraft which are open-loop unstable. This thesis stems from a need to understand the reasons for this. Modem methods are examined in order to determine their strengths and weaknesses when applied to industrial problems. As a representative situation, a modem control method, eigenstructure assignment, is examined. One objective of the research described in the thesis is to improve the application oriented aspects of the methodology of eigenstructure assignment. The purpose of this is that every facet of the method can then be explained in terminology that is familiar to the aircraft control engineer. Furthermore, the theory is developed such that it is compatible with easily understandable controller structures and control design strategies, to provide a control system with good performance and robustness characteristics. The design of a robust controller for a civil aircraft model developed by the GARTEUR (Group for Aeronautical Research and Technology in Europe) demonstrates the utility of eigenstructure assignment and culminates in suggestions as to when and where the method has its greatest strengths and weaknesses.
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Helldin, Tove. "Human-centred automation : with application to the fighter aircraft domain." Licentiate thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-21739.
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The working situation of fighter pilots is often very challenging. The pilots are requested to perform their tasks and make decisions in situations characterised by time-pressure, huge amounts of data and high workload, knowing that wrong decisions might result in fatal consequences. To aid the pilots, several automatic support systems have been implemented in modern fighter aircraft and will continue to be implemented in pace with technological advancements and new demands posed on the pilots. For example, innovations within the information fusion (IF) domain have made it possible to fuse large amounts of data, stemming from different sensors, databases etc., to create a better foundation for making decisions and act than would have been possible if the information sources had been used separately. However, there are both positive and negative effects of automation, such as decreased workload and improved situation awareness on the one hand, but skill degradation and complacent behaviour on the other. To avoid the possible negative consequences of automation, while at the same time ameliorating the positive ones, a human-centred automation (HCA) approach to system design has been proposed as a way of optimizing the collaboration between the human and the machine. As a design approach, HCA stresses the importance of a cooperative human-machine relationship, where the operator is kept in the automation loop. However, how to introduce HCA within the fighter aircraft domain as well as its implications for the interface and automation design of support systems within the field has not been investigated. This thesis investigates the implications of introducing HCA into the fighter aircraft domain. Through literature surveys and empirical investigations, general and domain specific HCA guidelines have been identified. These advocate, for example, that an indication of the reliability of the information and the recommendations provided by the different aircraft support systems must be given as well as that support for appropriate updates of the pilots’ individual and team awareness of the situation must be provided. A demonstrator, mirroring some of the identified guidelines, has been implemented and used to evaluate the guidelines together with system developers within the domain. The evaluation indicated that system developers of modern fighter aircraft implicitly incorporate many of the identified HCA guidelines when designing. However, the evaluation further revealed that to explicitly incorporate these guidelines into the development approach, preferably through the development of a domain specific style guide, would aid the system developers design automated support systems that provide appropriate support for the pilots. The results presented in this thesis are expected to aid developers of modern fighter aircraft support systems by incorporating HCA into the traditional simulator-based design (SBD) approach. This approach is frequently used within the field and stresses early and frequent user-involvement when designing, in which complementary HCA evaluations could be performed to further improve the support systems implemented from an automation perspective. Furthermore, it is expected that the results presented in this thesis will contribute to the research regarding how to incorporate the human operator in the information fusion processes, which has been recognised as a research gap within the IF field. Thus, a further contribution of this thesis is the suggestion of how the HCA development approach could be of aid when improving the interaction between the operator and the automated fusion system.Arbetssituationen för stridspiloter är ofta mycket utmanande. Piloterna måste utföra sina uppgifter och fatta beslut i stressiga situationer med stora informationsmängder och hög arbetsbörda, samtidigt som val av fel beslut kan leda till allvarliga konsekvenser. För att hjälpa piloterna har flera automatiska stödsystem implementerats i moderna stridsflygplan. Denna trend kommer att fortsätta i takt med nya tekniska framgångar och nya krav som ställs på piloterna. Forskning inom informationsfusion (IF) har bland annat gjort det möjligt att fusionera stora mängder data som härstammar från olika sensorer, databaser m.m. för att på så sätt skapa en bättre grund för att fatta beslut och agera än vad som hade varit möjligt om informationskällorna hade använts separat. Dock har både positiva och negativa effekter av automatisering rapporterats, såsom minskad arbetsbörda och förbättrad situationsuppfattning men även försämrad pilotprestation till följd av att de automatiska systemens prestanda inte övervakas. För att undvika negativa effekter av automation samtidigt som de positiva effekterna stärks har den så kallade människo centrerade automationen (HCA) lyfts fram som en möjlig väg att designa system där samverkan mellan automationen och den mänskliga operatören optimeras. Som en designapproach fokuserar HCA på viken av en samverkande människamaskin relation, där operatören hålls kvar i automatiseringsloopen. Men hur HCA kan introduceras inom stridsflygdomänen och dess implikationer för gränssnitts- och automationsdesign av stödsystem inom domänen har inte undersökts. Denna licentiatavhandling undersöker möjliga implikationer av att introducera HCA inom stridsflygdomänen. Genom litteraturundersökningar och empiriska studier har generalla och domänspecifika HCA riktlinjer identifierats, såsom att piloterna måste erbjudas en indikation angående tillförlitligheten hos den information och de rekommendationer som de olika implementerade stödsystemen i flygplanet har genererat, samt att stöd för att uppdatera piloternas individuella och gemensamma uppfattning av situationen måste ges. En demonstrator, som återspeglar några av de identifierade HCA riktlinjerna, har implementerats och använts för att utvärdera riktlinjerna tillsammans med systemutvecklare inom domänen. Denna utvärdering påvisade att systemutvecklare inom stridsflygdomänen implicit använder sig av många av de identifierade HCA riktlinjerna under designprocessen, men att explicit inkludera dessa i en domänspecifik design guide skulle kunna hjälpa dem att designa automatiska system som erbjuder lämpligt stöd för piloterna. De resultat som presenteras i denna licentiatavhandling förväntas kunna hjälpa utvecklare av moderna stridsflygsystem genom att inkludera HCA i den traditionella simulator-baserade designapproachen (SBD). Denna approach används flitigt inom området och fokuserar på tidigt och återkommande användardeltagande vid designarbetet, där komplementära HCA utvärderingar skulle kunna genomföras för att förbättra de stödsystem som implementeras från ett automationsperspektiv. Det förväntas även att de resultat som presenteras i denna avhandling kommer att bidra till forskningen kring hur operatörer kan påverka fusionsprocessen, vilket har identifierats som ett område där mer forskning behövs inom IF området. Ytterligare ett bidrag av denna avhandling är därför det förslag som ges på hur HCA utvecklingsprocessen skulle kunna användas för att förbättra interaktionen mellan operatören och det automatiska fusionssystemet.
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XIE, QIULIN. "PROBABILISTIC DESIGN OPTIMIZATION OF BUILT-UP AIRCRAFT STRUCTURES WITH APPLICATION." MSSTATE, 2003. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07292003-211728/.
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This thesis discusses a methodology for probabilistic design optimization of aircraft structures subject to a multidisciplinary set of requirements originating from the desire to minimize structural weight while fulfilling the demands for quality, safety, producibility, and affordability. With this design methodology as the framework, a software is developed, which is capable of performing design optimization of metallic built-up beam structures where the material properties, external load, as well as the structural dimensions are treated as probabilistic random variables. The structural and failure analyses are based on analytical and semi-empirical methods whereas the component reliability analysis is based on advanced first-order second moment method. Metrics-based analytical models are used for the manufacturability analysis of individual parts with the total manufacturing cost estimated using models derived from the manufacturing cost / design guide developed by the Battelle¡¯s Columbus Laboratories. The resulting optimization problem is solved using the method of sequential quadratic programming. A wing spar design optimization problem is used as a demonstrative example including a comparison between non-buckling and buckling web design concepts. A sensitivity analysis is performed and the optimization results are used to highlight the tradeoffs among weight, reliability, and manufacturing cost.
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Leite, Nelson Paiva Oliveira, Leonardo Mauricio de Faria Lopes, and Fernando Walter. "The Design of an Application Used for Aircraft Stability Evaluation." International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/605926.
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ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, CaliforniaOne of the most important characteristics of an aircraft is its capability to return to its stable trimmed flight state after the occurrence of a disturbance or gust without the pilot intervention. The evaluation of such behavior, known as the aircraft stability, is divided into three sections: Lateral; Directional; and Longitudinal stabilities. The determination of the stability of an experimental aircraft requires the execution of a Flight Test Campaign (FTC). For the stability FTC the test bed should be equipped with a complete Flight Test Instrumentation (FTI) System which is typically composed by: a Pulse Code Modulation (PCM) Data Acquisition System (DAS); A sensor set; An airborne transmitter; and A data recorder. In the real-time operations, live data received over the Telemetry Link, that are processed, distributed and displayed at the Ground Telemetry System (GTS) enhances the FTC safety level and efficiency. The due to the lack of reliability, recorded data is retrieved in the post mission operations to allow the execution of data reduction analysis. This process is time consuming because recorded data has to be downloaded, converted to Engineering Units (EU), sliced, filtered and processed. The reason for the usage of this less efficient process relies in the fact that the real-time Telemetry data is less reliable as compared to recorded data (i.e. noisier). The upcoming iNET technology could provide a very reliable Telemetry Link. Therefore the data reduction analysis can be executed with live telemetry data in quasi-real time after the receipt of all valid tests points. In this sense the Brazilian Flight Test Group (GEEV) along with EMBRAER and with the support of Financiadora de Estudos e Projetos (FINEP) started the development of several applications. This paper presents the design of a tool used in the Longitudinal Static Stability Flight Tests Campaign. The application receives the Telemetry data over either a TCP/IP or a SCRAMnet Network, performs data analysis and test point validation in real time and when all points are gathered it performs the data reduction analysis and automatically creates Hyper Terminal Markup Language (HTML) formatted tests reports. The tool evaluation was executed with the instruction flights for the 2009 Brazilian Flight Test School (CEV). The result shows an efficiency gain for the overall FTC.
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Miller, P. "An experimental study of sonic and supersonic nozzles and their application to high pressure ejectors for aircraft attitude control." Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380891.
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A study has been conducted of reaction controls for VSTOL aircraft using thrust augmenting ejector techniques. Rapid mixing nozzles have been developed for high pressure ejectors. Mass flow increases for sonic nozzles of up to 50\ at x/D=8 were recorded, compared with plain circular nozzles. Their use was found to improve the thrust performance of a simple ejector by 9\, and larger increases are believed possible. Results from an ejector performance prediction model were successfully compared with experimental data. The use of rapid mixing nozzles in a practical ejector design has been assessed. It is predicted that a maximum thrust increment of 20\ ·could be achieved, compared with a simple fully expanded jet flow.
26
Intaratep, Nanyaporn. "The Investigation of an Inboard-Winglet Application to a Roadable Aircraft." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/33519.
Full textAbstract:
The inboard-winglet concept was examined for its flow characteristics by testing for pressure coefficients over the wing and winglet surface in the Virginia Tech Stability Wind Tunnel over a range of freestream velocity and angle of attack. The results were analytically applied to calculate aircraft performance of a roadable aircraft, Pegasus II, which used the inboard-winglet concept in its design. The results proved that this concept has the potential to increase a wing lift coefficient at the right combination of thrust setting and freestream velocity better than a conventional wing-propeller arrangement. The lift coefficient inside the winglet channel was approximated as 2D in behavior. It is also shown that the winglets produce thrust at a positive-lift wing configuration. In the Pegasus II, the vertical stabilizers act like inboard winglets and produce a thrust component from its resultant force, giving 5.2% improvement in its effective aspect ratio and resulting in an induced-drag decrease. With an application of the new wing concept, the Pegasus II performance is comparable to other general aviation aircraft.Master of Science
27
Pispitsos, Stelios P. "Neural network for control signal reconstruction in non-linear systems with an application to aircraft dynamics." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=768.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains xv, 125 p. : ill. (some col.) Vita. Includes abstract. Includes bibliographical references (p. 93-95).
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Smith, Phillip Raymond. "Application of Eigenstructure Assignment to the control of powered lift combat aircraft." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277796.
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Eslimy-Isfahany, Seyed Hamid Reza. "Dynamic response of thin-walled composite structures with application to aircraft wings." Thesis, City University London, 1998. http://openaccess.city.ac.uk/7719/.
Full textAbstract:
A general analytical method is developed to study first the buckling behaviour and then the dynamic characteristics of thin-walled composite structures with the presence of bending torsion coupling. The dynamic response theory incorporates the dynamic stiffness matrix approach and generalised coordinates using the normal mode method. Structural components considered are thin-walled laminated composite beams with carbon-fibre, glass-fibre or other reinforced plastic lay-ups. The examples of such beams and their applications include aircraft wings, hulls of ships, helicopter and wind turbine blades. All assumptions made in this work are based on elastic linear small deflection beam theory so that the overall response of the beam is represented by the superposition of all individual responses in each mode. Bending-torsion coupling effects arising from the anisotropic nature of fibrous composites, as well as due to non-coincident centroid and geometric shear centre of the beam crosssection, are the main contributory elements when developing the theory. The beam is subjected to time dependent forces and/or torques which can be either concentrated or distributed over its length. Both deterministic and random loads are considered. An important example of a deterministic load is one that varies harmonically in time. The Duhamel integral is employed to calculate the response to any arbitrary time dependent deterministic load. The random load is assumed to be Gaussian, having both stationary and ergodic properties. The evaluation of the response to the random load is carried out in the frequency domain by relating the Power Spectral Density (PSD) of the output to that of the input using the complex frequency response function. A number of PSD distributions are considered as random input in order to determine the PSD of the dynamic response. Atmospheric turbulence, which is considered to be one of the forms of random excitation, is modelled using the von Karman spectra for composite aircraft wings. In order to establish the methodology, bending-torsion coupled metallic beams are first ,investigated. The bending-torsion coupling in such beams occurs due to non-coincident centroid and geometric shear centre of the beam cross-section. The natural frequencies and mode shapes in undamped free vibration are obtained and the significance of generalised ,mass in each of the modes of vibration is evaluated. A normal mode method is then used to compute the frequency response function of the beam. The effects of shear deformation rotatory inertia and axial load on the frequencies, mode shapes and dynamic response characteristics are demonstrated. It was essential at an earlier stage of the investigation to validate the chosen composite beam modelling. Among all the different techniques used to determine the rigidities of a composite beam, the buckling load provides a reasonable estimate. The elastic critical buckling loads of thin-walled laminated composite columns for various end conditions are established theoretically using the exact stiffness method. The effect of shear deformation on the buckling characteristics of the column is demonstrated. Experiments are carried out to establish the elastic critical buckling load of metallic and laminated composite columns. Theoretical predictions of the buckling behaviour are corroborated by experimental results and other published results. The investigation is then focused on composite beams, but the response analysis of such beams is significantly more complicated than that of their metallic counterparts. This is mainly due to anisotropic characteristics of laminated fibrous composites. A detailed parametric study with the variation of significant composite parameters, such as ply angle, is undertaken and the importance of the results are highlighted. A suite of computer programs in FORTRAN is developed to predict the bucklingbehaviour, the free vibration and the responsec characteristics of thin-walled composite or metallic beams based on the theory proposed. Numerical results are presented, fully discussed and commented on.
30
Bertrand, Denis J. S. R. "Application of neural network to adaptive control theory for super-augmented aircraft." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/43760.
Full textAbstract:
The neural network structures developed in this thesis demonstrate the ability of parallel distributed processing in solving adaptive control problems. Adaptive control theory implies a combination of a control method and a model estimation. The control method investigated is the Lyapunov Model Reference Adaptive Control or MRAC and the model estimation investigated is the linear least square estimator. The neural network theory is introduced with emphasis on the back-propagation algorithm. The implementation of the neural network adaptive control structure is demonstrated on the longitudinal dynamics of the X-29 fighter aircraft. Three configurations are proposed to train the neural network adaptive control structures to provide the appropriate inputs to the unstable X-29 plant so that desired responses could be obtained. These configurations are presented in eight cases, which emulates stable systems like the X-29 closed-loop plant or the optimal and the limited X-29 controllers, and unstable systems like the X-29 plant or its inverse.
31
Ghobbar, Adel Abulgassem. "The application of material requirements planning (MRP) system to aircraft parts inventory." Thesis, City University London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269342.
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Burgess, C. A. R. "The application of aero gas turbine engine monitoring systems to military aircraft." Thesis, Cranfield University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232816.
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33
Hadzalic, Deniz. "Application of neural networks for prediction of subjectively assessed interior aircraft noise." Thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-247502.
Full textAbstract:
Products are increasingly judged by their acoustic performance; and during the last decades, sound quality in general has gained a lot of attention, both from academia and companies. An obstacle in the evaluation of the sound quality is that jury testing is time consuming and require human resources. In an attempt to overcome these limitations, neural networks have been applied in this work with the objective to find a relation between human acoustic perception and a quantity possible to physically measure. For this purpose, 30 of 170 sound samples of interior aircraft noise have been subjectively assessed during jury testing with 40 participators. With extracted psychoacoustic features from the sound samples and the obtained results from the jury testing, a shallow neural network (SNN) with one hidden layer is trained and tested. The prediction performance of the SNN is compared with another alternative method - multiple linear regression. The evaluation of the remaining un-assessed sound samples is predicted by the trained SNN and implemented in the deep learning neural networks, such as Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN).
34
Gibson, Travis Eli. "Closed-loop Reference Model adaptive control : with application to very flexible aircraft." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/87974.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 187-192).
One of the main features of adaptive systems is an oscillatory convergence that exacerbates with the speed of adaptation. Over the past two decades several attempts have been made to provide adaptive solutions with guaranteed transient properties. In this work it is shown that Closed-loop Reference Models (CRMs) can result in improved transient performance over their open-loop counterparts in model reference adaptive control. In addition to deriving bounds on L-2 norms of the derivatives of the adaptive parameters which are shown to be smaller, an optimal design of CRMs is proposed which minimizes an underlying peaking phenomenon. The analytical tools proposed are shown to be applicable for a range of adaptive control problems including direct control, composite control with observer feedback and partial states accessible control. In addition a detailed study of the applicability of CRM adaptive control to very flexible aircraft is presented. Following the NASA Helios flight mishap in 2003 there has been a push for greater understanding of the aerodynamic-structural coupling that occurs in light, very flexible, flying wings. Previous efforts in that direction revealed that the flexible aircraft had instability in the phugoid mode for large dihedral angles and that including the flexible dynamics was necessary to arrive at an appropriate trim condition. In this thesis, we show how these large dihedral excursions can occur in the presence of turbulence, by constructing an overall nonlinear model that captures the dominant dynamics of a very flexible aircraft. The thesis closes with the application of CRM adaptive control to the VFA model.
by Travis Eli Gibson.
Ph. D.
35
Sahyoun, Alexandre Paul. "Application of aircraft sequencing to minimize departure delays at a busy airport." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92700.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 73-74).
In the face of large increases in the number of passengers and flights, busy airports worldwide have been trying to optimize operating efficiency and throughput and minimize congestion on a daily basis. In the case of departures, measures can be taken at the gate, on the taxiway system or at the runway queue to minimize departure delays and/or the cost of unavoidable delays. This cost includes needless fuel consumption and noxious emissions. In this thesis, we focus primarily on runway queue optimization. The first part of this work consists of designing a generic simulation which models specific days of operations at an airport. Using as input the schedule of operations specific to the modeled airport, the simulation processes all departures and stores the characteristic times of the process for each departing aircraft. The quantities of interest are either incrementally computed by the simulation or modeled using probability distributions derived from airport-specific data. We then present a dynamic programming approach to sequencing departing aircraft at the runway queue. Two algorithms are presented based on the idea of Constrained Position Shifting, which maintains a high level of fairness in the order in which aircraft gain access to runways, while also improving efficiency by comparison to First Come First Served sequencing. The objective of the first algorithm is to minimize makespan, and that of the second to minimize delays. We then focus on a specific airport, which has been experiencing one of the fastest growth rates in the industry. We analyze the output of our simulation as applied to this airport and accumulate insights about congestion at the departure runways. We next apply this sequencing algorithm to this specific airport using multiple demand profiles that represent both the current traffic levels, as well as anticipated future ones that would result in more congestion. We give quantitative arguments to confirm the positive impact of the optimization on the airport's operations. We also emphasize the importance of the aircraft mix on the techniques' performance and show that the sequencing algorithms provide higher benefits (in terms of reducing delays) as the mix becomes more heterogeneous.
by Alexandre Paul Sahyoun.
S.M.
36
Parkins, Michael A. (Michael Andrew) 1976. "Application of variation risk management processes in commercial aircraft design and manufacture." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/34776.
Full textAbstract:
Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; in conjunction with the Leaders for Manufacturing Program at MIT, 2004.Includes bibliographical references (p. 95-96).
Companies and academics have known for many years that reducing variation in production processes can decrease production cost, increase product quality, and have substantial impact on overall profitability. Tools to help companies track, assess, and improve variation are numerous and readily available, but gradually an understanding has emerged from implementing these tools that significant amounts of variation cannot be removed from the factory, and the only way to continue to improve cost and quality beyond diminishing returns is to move upstream in the process and design parts and assemblies that are more variation resistant, or maintain quality functionality over a broader range of variation. One methodology emerging to help companies with this task is Variation Risk Management (VRM). The problem with VRM and other methodologies is that they are often treated as side processes that do not get well integrated into the overall product development process. This results in training and improvement activities that optimize VRM on its own rather than maximizing the effect VRM has on the product. In order to do this the initiative failure cycle must be understood, and attention must be focused on information management, management and organizational support, and process like communication and integration.
by Michael A. Parkins.
S.M.
M.B.A.
37
Kanyoo, Prin. "Mathematical model of high speed planing dynamics and application to aircraft ditching." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/403070/.
Full textAbstract:
A nonlinear mathematical model capable of predicting loads and motions of high speed planing craft in the longitudinal plane has been developed. The development of the model is based on the mathematical model presented by Zarnick (1978). Following the principle of 2D strip theory and wedge water entry problem, a high speed planing hull is divided into a number of transverse sections. Sectional forces and motions are evaluated, and then, by integrating along the ship length, total force and moment are obtained which leads to corresponding instantaneous acceleration. By integration using a time marching scheme, velocity and displacement are obtained. The influence of the controlling parameters, such as number of sections and time step, on the accuracy and stability of the simulation in calm water, regular and irregular waves is investigated. The accuracy of the underlying mathematical model is investigated and the deficiencies identified. The optimum model is finally validated against the original model of Zarnick(1978) and the experiments of Fridsma (1969). An extension of the model to be capable of simulating roll motion is proposed and implemented. This extension may be useful when the prediction of high speed planing motions in oblique seas is proposed. The initial validation process has been carried out but subjected to the full validity of application. Moreover, as the original approach of the mathematical model was used in prediction of seaplane landing (Wagner, 1931), an additional aim and objective to the present PhD project is to find a novel technique to predict the loads on fuselage of an aircraft emergently landing (ditching) into the water. Experimental tests related to these simulations are planned and carried out in order to use their results as validation references to the modified mathematical model. The deliverable of the project is an analysis of optimization of the mathematical model capable of predicting loads and motions of high speed planing craft. As well as the implementation of capability of predicting impact loads and initial post-impact motions of aircraft ditching into the water.
38
Gaya, Caroline. "Toward lithium-air batteries for aircraft application : a combined experimental/modeling study." Thesis, Amiens, 2019. http://www.theses.fr/2019AMIE0053.
Full textAbstract:
Le développement des avions plus électriques nécessite des systèmes de stockage électrochimique à fortes densité d'énergie, à la fois gravimétrique et volumétrique. Parmi les diverses solutions envisagées, les batteries lithium-air air sont apparues comme une solution envisageable du fait de leur densité d'énergie théorique élevée. Cependant, les performances obtenues en pratique sont bien éloignées des théoriques à cause des nombreux verrous technologiques dont souffrent ces batteries. Afin d'augmenter les performances des batteries une grande partie des travaux a eu pour objectif de créer des électrodes texturées prenant en compte les phénomènes limitant tels que la diffusion de l'oxygène, le remplissage des pores ou encore la passivation de l'électrode afin d'améliorer la capacité de décharge. D'abord étudiées grâce à la modélisation, le développement en laboratoire a ensuite permis de créer des électrodes bi-poreuses pouvant atteindre jusqu'à 70 % de la capacité théorique. Par la suite, en vue d'un manque de reproductibilité certain, l'étude des paramètres pouvant induire une variation des capacités de décharge a été mise en place. Il est alors apparu que les batteries lithium-air sont extrêmement sensibles aux paramètres modifiant sa cinétique et l'étape de nucléation : la température, la densité de courant et l'état de surface de l'électrodeTo develop more electrical aircrafts, energy storage systems with high gravimetric and volumetric energy densities are required. Among the potential solutions, lithium-air batteries appeared as a promising choice due to their high theoretical energy densities. However, such systems suffer from many limitations which induces low practical energy densities.To enhance the batteries performances, a study on the electrode texture was implemented taking into account the limiting phenomena of passivation, pore clogging and oxygen diffusion. First studied by the help of modeling, development of these electrodes was later achieved at lab scale. The bi-porous electrodes obtained could reached the 70 % of the expected capacity. Later, due to the reproducibility issues observed a second study was settled to limit variation of the discharge capacities. It was noticed that lithium-air batteries were extremely sensitive to the parameters impacting kinetics and more especially the nucleation step. So temperature, current density and electrode surface should be perfectly mastered
39
Ančík, Zdeněk. "Mechatronic Design and Verification of Autonomic Thermoelectric Energy Source for Aircraft Application." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-234600.
Full textAbstract:
Předložená disertační práce řeší komplexní mechatronický návrh autonomního termoelektrického zdroje energie pro letecké aplikace. Na základě dostupných zdrojů a literatury práce popisuje současný stav problematiky. V práci jsou prezentovány simulační modely MEMS termoelektrických článků, které jsou ověřeny experimentálním testováním a hodnotami dostupnými od výrobce. Na základě metodiky model-besed design byly navrženy a vyrobeny tři demonstrátory. Jejich vlastnosti byly testovány v reálných podmínkách na letecké pohonné jednotce.
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Miftach, Fetri Emirudin Hartawan. "The application of multivariable control methods to gust load alleviation analysis." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311343.
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Curtius, Joachim Walther Julius. "Aerosol sulfuric acid in the atmosphere and in jet aircraft exhaust development and application of a novel aircraft-borne mass spectrometer apparatus /." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=961937947.
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42
Gallimore, Craig Allen. "Passive Viscoelastic Constrained Layer Damping Application for a Small Aircraft Landing Gear System." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/35350.
Full textAbstract:
The main purpose of this report was to test several common viscoelastic polymers and identify key attributes of their applicability to a small aircraft landing gear system for improved damping performance. The applied viscoelastic damping treatment to the gear was of a constrained layer type, promoting increased shear deformation over free surface treatments, and therefore enhanced energy dissipation within the viscoelastic layer. A total of eight materials were tested and analyzed using cyclic loading equipment to establish approximate storage modulus and loss factor data at varying loading frequencies. The three viscoelastic polymers having the highest loss factor to shear modulus ratio were chosen and tested using a cantilever beam system. A Ross, Kerwin, and Ungar analysis was used to predict the loss factor of the cantilever beam system with applied treatment and the predictions were compared to experimental data.
Customer requirements often govern the scope and intensity of design in many engineering applications. Limitations and constraints, such as cost, weight, serviceability, landing gear geometry, environmental factors, and manufacturability in regards to the addition of a viscoelastic damping treatment to a landing gear system are discussed.
Based on results found from theoretical and experimental testing, application of a damping treatment to a small aircraft landing gear system is very promising. Relatively high loss factors were seen in a cantilever beam for simple single layer constrained treatments for very low strain amplitudes relative to strains seen during loading of the landing gear. With future design iterations, damping levels several times those seen in this document will be seen with a constrained treatment applied to a landing gear system.Master of Science
43
Mathews, J. "The theory and application of heated films for the measurement of skin friction." Thesis, Cranfield University, 1985. http://dspace.lib.cranfield.ac.uk/handle/1826/5711.
Full textAbstract:
The use of
hot
surface films for
measuring skin
friction
is
examined. It is
shown that all existing theories, which
neglect
heat
conduction within the substrate, are
inadequate
in
predicting the variation of
heat loss from the film
with
skin friction. A
more physically realistic theory is
presented which accounts for the conductive and convective
heat transfer into the flow and also
heat
conduction within
the substrate. This leads to a more general relationship
between
skin friction
and
heat loss from the film.
Experiments
conducted
in flat plate
laminar
and
turbulent
boundary layer flow show that this relationship
is
more
accurate than previous
forms.
The time and temperature dependence of the heat loss
from the hot film are also explored theoretically and experi-
mentally. The
effect of surface misalignment of the film is
shown to
alter significantly the convective heat transfer.
This
effect is
more pronounced in laminar flow than in
turbulent flow.
Using
a glue-on
hot film
probe, calibrations relating
the
heat loss to skin friction
were found to be different in
laminar
and turbulent flow.
An
experimental operating procedure for the use of
hot
surface films for measuring skin friction is proposed which
significantly increases the accuracy of the technique.
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Maeng, Honjae. "An application of technological maturity assessment to ROKAF T-50 aircraft production program." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Dec%5FMaeng.pdf.
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Fraracci, Alessandro. "Model-based failure-modes-and-effects analysis and its application to aircraft subsystems /." Heidelberg : Akad. Verl.-Ges. [u.a.], 2010. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=018771234&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Sillén, Mattias. "Application of Parallel Computers to Enhance the Flow Modelling Capability in Aircraft Design." Licentiate thesis, Linköping University, Linköping University, Department of Management and Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6398.
Full textAbstract:
The development process for new aircraft configurations needs to be more efficient in terms of performance, cost and time to market. The potential to influence these factors is highest in early design phases. Thus, high confidence must be established in the product earlier than today. To accomplish this, the concept of virtual product development needs to be established. This implies having a mathematical representation of the product and its associated properties and functions, often obtained through numerical simulations. Building confidence in the product early in the development process through simulations postpones expensive testing and verification to later development stages when the design is more mature.
To use this in aerodynamic design will mean introducing more advanced physical modelling of the flow as well as significantly reducing the turn around time for flow solutions.
This work describes the benefit of using parallel computers for flow simulations in the aircraft design process. Reduced turn around time for flow simulations is a prerequisite for non-linear flow modelling in early design stages and a condition for introducing high-end turbulence models and unsteady simulations in later stages of the aircraft design process. The outcome also demonstrates the importance of bridging the gap between the research community and industrial applications.
The computer platforms are very important to reduce the turn around time for flow simulations. With the recent popularity of Linux–clusters it is now possible to design cost efficient systems for a specific application. Two flow solvers are investigated for parallel
performance on various clusters. Hardware and software factors influencing the efficiency are analyzed and recommendations are made for cost efficiency and peak performance.
Report code: LiU-TEK-LIC-2006:27.
47
Sillén, Mattias. "Application of parallel computers to enhance the flow modelling capability in aircraft design /." Linköping : Department of Mechanical Engineering, Linköpings universitet, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6398.
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Wilde, Paul Ivan Anthony. "The application of circulation control for three axis control of a tailless aircraft." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.506598.
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Gastelum, Victoria Elena 1973. "Application of lean manufacturing technique for the design of the aircraft assembly line." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8478.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002."June 2002."
Includes bibliographical references (p. 103-104).
The final assembly line for the Boeing Commercial Airplanes 717 Program is currently implementing "The 9 Tactics", a methodology based on the lean manufacturing principles to transform the current processes to continuous moving lines. The first two tactics, Value Stream Mapping and Balancing the Line define the manufacturing system configuration (the quantity of airplanes to load in the conveyor, headcount and workload per workstation) and the process to develop the production execution plans. Understanding of the tradeoffs in the allocation of resources when selecting the most profitable manufacturing system configuration is a complex task for the Industrial Engineering department. The preparation of these plans is iterative and time-consuming, complicated by constraints such as assembly sequences and space limitations. The problem solved during the internship was to propose a methodology or framework for the implementation of the Value Stream Mapping and Balancing the Line tactics, considering the economics involved and the frequent production fluctuations in the production rate. The framework proposed is based on lean techniques and economic analysis, and is the main product delivered to the sponsor company. The economic analysis of the assembly line configuration alternatives is supported by the application of the Economic Profit financial metric (also known as Economic Value Added).
by Victoria Elena Gastelum.
S.M.
50
Espitia, Alejandro E. "Application of overset grids for aerodynamic assessment of an advanced civil transport aircraft." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/87483.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, February 2014.Cataloged from PDF version of thesis. "September 2013." Page [80] blank.
Includes bibliographical references (pages 77-79).
Simulations are presented for 1:20 and 1:11 scale configurations of an advanced civil transport designed to use boundary layer ingestion (BLI). Comparison with wind tunnel results on unpowered configurations show that the computed and measured lift slopes agree within 15% and the drag at simulated cruise point to within 20%. Computations have been carried out for an initial and a redesigned configuration of the aft section of the aircraft. The redesigned version showed a reduction in lift and an increase in drag compared to the initial design. The mechanical power for a 1:11 powered configuration at cruise, without BLI, has also been calculated.
by Alejandro E. Espitia.
S.M.