Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: This thesis presents research contributing towards the automatic control of formation flight for commercial airliners. The motivation behind this research is to ultimately reduce fuel consumption of the trailing airliner through the utilisation of the aerodynamic coupling interactions between the trailing airliner and the wake vortices of the leading airliner. A traditional model for an airliner in isolated flight is developed and expanded to include formation flight interactions as functions of the vertical and lateral separation between the trailing and leading airliners. A trim analysis is done, and resulting actuator trims are presented over ranges of lateral and vertical separation. Regions of reduced throttle setting are identified, as well as risks and challenges for maintaining formation within these regions. These regions comprise of a potentially risky and challenging region, coined the "sandwich region"; as well as a safer, more practically viable region, coined the "outer region". The former is a narrow region sandwiched between two regions that are untrimmable with respect to maximum aileron deflection, whereas the latter is only constrained by an inboard untrimmable bound, but has less significant drag reduction. Subsequently, a state space representation is constructed, and a linear dynamics analysis follows. It is determined that the trimmed, uncontrolled trailing airliner is naturally unstable; hence a flight control system is required for stability. Furthermore, the analysis revealed that the dynamics stay essentially constant, especially for conventional modes, within the outer region. In the sandwich region however, the dynamics change much more drastically. Next, a control system for the conventional airliner is designed based on the available information of current representative fly-by-wire systems; and its performance is analysed in formation flight scenarios by means of both linear and non-linear simulations. It is found that, given sufficiently high control law gains, particularly for lateral controllers, the conventional architecture is sufficient for maintaining formation. Additional structures are suggested, such as saturation elements to limit the lateral separation rate and acceleration; and a state machine controller, with states for entering and exiting the wake vortices. Following this, a robustness analysis was done by once again evaluating the linear dynamics over ranges of lateral and vertical separation; this time with the flight controllers augmented into the linear models. The robustness analysis proved that the controllers are robust against lateral and vertical separation perturbation, at least in the outer region. Finally, a series of non-linear simulations prove the success of the control system in maintaining formation in various atmospheric turbulence conditions. Furthermore, the trailing airliner consistently has a reduced throttle setting, though with greater dynamic throttling compared to the leading airliner. Lastly, it is determined that the standard deviations of the control surface defection of the trailing airliner are in the same order of magnitude as those of the leading airliner in simulations with moderate turbulence. Interestingly, it is found that the elevator deflection of the trailing airliner has a lower standard deviation than that of the leading airliner, possibly due to the leading airliner carrying the burden of regulating the formation's altitude. / AFRIKAANSE OPSOMMING: Hierdie tesis handel oor navorsing wat 'n bydrae maak tot die outomatiese vlugbeheer van kommersiële passasiersvliegtuie in formasievlug. Die navorsing is gemotiveer deur die potensiële vermindering in die brandstofverbruik van die volgervliegtuig wat verkry kan word deur voordeel te trek uit die aerodinamiese koppeling tussen die volgervliegtuig en die nasleurvortekse van die voorste vliegtuig. 'n Tradisionele vlugmeganika model vir 'n passasiersvliegtuig is ontwikkel en uitgebrei om formasievluginteraksies in te sluit, as funksies van die vertikale en laterale skeidingsafstande tussen die volgervliegtuig en die voorste vliegtuig. 'n Ewewig-analise is uitgevoer, en die nodige ewewig-instellings is bereken oor die bereik van moontlike laterale en vertikale skeidingsafstande. Twee gebiede van verminderde enjin-krag instellings is gedentifiseer, en die risikos en uitdagings verbonde aan formasievlug in hierdie gebiede is beskou. Twee gebiede is uitgeken: 'n uitdagende, potensieel gevaarlike gebied, genoem die "sandwich" of "ingeperkte" gebied; en 'n veiliger, meer lewensvatbare gebied, genoem die "outer" of buitenste gebied. Die "ingeperkte" gebied is 'n baie nou gebied wat ingedruk is tussen twee ewewig-oninstelbare gebiede, waar aileron de eksie instellings vereis word wat die maksimum moontlike de eksies oorskry. Die "buitenste" gebied is 'n gebied wat net aan die binnekant begrens word deur 'n ewewig-oninstelbare gebied, maar wat nie so 'n groot besparing in brandstofverbruik bied as die "ingeperkte" gebied nie. Vervolgens is 'n toestandsveranderlike voorstelling van die vlugdinamika afgelei, en 'n dinamiese analise is uitgevoer. Die dinamiese analise het gewys dat die ewewig-ingestelde, onbeheerde vliegtuig natuurlik onstabiel is, en dat 'n vlugbeheerstelsel benodig word om vlugstabiliteit te verseker. Daarby het die analise ook onthul dat die vlugdinamika baie min verander oor die bereik van die "buitenste" gebied, maar dat die vlugdinamika baie meer drasties verander oor die bereik van die "ingeperkte" gebied. 'n Konvensionele vlugbeheerstelsel vir die vliegtuig is volgende ontwerp, gebaseer op beskikbare inligting oor die argitektuur van tipiese "fly-by-wire" beheerstelsels wat tans op passasiersvliegtuie gebruik word. Die prestasie van die konvensionele vlugbeheerstelsel in formasievlugtoestande is ontleed deur middel van beide lineêre en nie-lineêre simulasies. Die simulasies het gewys dat die konvensionele vlugbeheerargitektuur in staat is om formasievlug te handhaaf, gegee dat voldoende hoë beheeraanwinste gebruik word. Bykomende strukture is voorgestel, insluitendend versadigingselemente om die koers en versnelling van die laterale skeidingsafstand te beperk; en 'n toestandsmasjien-beheerder, met toestande om die nasleurvortekse binne te gaan en te verlaat. 'n Robuustheidsanalise is ook gedoen, deur die geslotelusdinamika met die beheerders ingesluit te analiseer oor die bereik van laterale en vertikale skeidingsafstande. Die robuustheidsanalise het gewys dat die beheerders wel robuust is oor die bereik van beide laterale en vertikale skeidingsafstande, ten minste in die "buitenste" gebied. Ten slotte is 'n omvattende reeks nie-lineêre simulasies uitgevoer om die vermoë van die vlugbeheerstelsel om formasievlug te behou te bevestig in 'n verskeidenheid van turbulensietoestande. Die simulasies het verder gewys dat die volgervliegtuig deurgaans 'n verminderde enjin-krag instelling het, maar met aansienlik meer dinamiese enjin-krag instelling variasies vergeleke met die voorste vliegtuig. Laastens het die simulasies gewys dat die standaard afwykings van die volgervliegtuig se beheeroppervlakde eksies van dieselfde ordegrootte is as dié van die voorste vliegtuig. Interessant genoeg is bevind dat die elevator defleksies van die volgervliegtuig 'n laer standaardafwyking het as dié van die voorste vliegtuig, waarskynlik omdat die voorste vliegtuig die groter las dra om die formasie se hoogte te reguleer.

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: This thesis presents a robust, sampling-based path planning algorithm for commercial airliners that simultaneously performs collision avoidance both with intruder aircraft and terrain. The existing resolution systems implemented on commercial airliners are fast and reliable; however, they do possess certain limitations. This thesis aims to propose an algorithm that is capable of rectifying some of these limitations. The development and research required to derive this conflict resolution system is supplied in the document, including a detailed literature study explaining the selection of the final algorithm. The proposed algorithm applies an incremental sampling-based technique to determine a safe path quickly and reliably. The algorithm makes use of a local planning method to ensure that the paths proposed by the system are indeed flyable. Additional search optimisation techniques are implemented to reduce the computational complexity of the algorithm. As the number of samples increases, the algorithm strives towards an optimal solution; thereby deriving a safe, near-optimal path that avoids the predicted conflict region. The development and justification of the different methods used to adapt the basic algorithm for the application as a confiict resolution system are described in depth. The final system is simulated using a simplified aircraft model. The simulation results show that the proposed algorithm is able to successfully resolve various conflict scenarios, including the generic two aircraft scenario, terrain only scenario, a two aircraft with terrain scenario and a multiple aircraft and terrain scenario. The developed algorithm is tested in cluttered dynamic environments to ensure that it is capable of dealing with airport scenarios. A statistical analysis of the simulation results shows that the algorithm finds an initial resolution path quickly and reliably, while utilising all additional computation time to strive towards a near-optimal solution. / AFRIKAANSE OPSOMMING: Hierdie tesis bied 'n robuuste, monster-gebaseerde roetebeplanningsalgoritme vir kommersiële vliegtuie aan, wat botsingvermyding met indringervliegtuie en met die terrein gelyktydig uitvoer. Die bestaande konflikvermyding- stelsels wat op kommersiële vliegtuie geïmplementeer word, is vinnig en betroubaar; dit het egter ook sekere tekortkominge. Hierdie tesis is daarop gemik om 'n algoritme voor te stel wat in staat is om sommige van hierdie tekortkominge reg te stel. Die ontwikkeling en navorsing wat nodig was om hierdie konflik-vermyding-algoritme af te lei, word in die dokument voorgelê, insluitende 'n gedetailleerde literatuurstudie wat die keuse van die finale algoritme verduidelik. Die voorgestelde algoritme pas 'n inkrementele, monster-gebaseerde tegniek toe om vinnig en betroubaar 'n veilige roete te bepaal. Die algoritme maak gebruik van 'n lokale beplanningsmetode om te verseker dat die roetes wat die stelsel voorstel inderdaad uitvoerbaar is. Aanvullende soektog-optimeringstegnieke word geïmplementeer om die berekeningskompleksiteit van die algoritme te verlaag. Soos die aantal monsters toeneem, streef die algoritme na 'n optimale oplossing; sodoende herlei dit na 'n veilige, byna-optimale roete wat die voorspelde konflikgebied vermy. Die ontwikkeling en regverdiging van die verskillende metodes wat gebruik is om die basiese algoritme aan te pas vir die toepassing daarvan as 'n konflik-vermyding-stelsels word in diepte beskryf. Die finale stelsel word gesimuleer deur 'n vereenvoudigde vliegtuigmodel te gebruik. Die simulasie resultate dui daarop dat die voorgestelde algoritme verskeie konflikscenario's suksesvol kan oplos, insluitend die generiese tweevliegtuigscenario, die slegs-terreinscenario, die tweevliegtuig-met-terreinscenario en die veelvuldige vliegtuig-enterreinscenario. Die ontwikkelde algoritme is in 'n beisge (cluttered), dinamiese omgewing getoets om te verseker dat dit 'n besige lughawescenario kan hanteer. 'n Statistiese ontleding van die simulasie resultate bewys dat die algoritme vinnig en betroubaar 'n aanvanklike oplossingspad kan vind, addisioneel word die oorblywende berekeningstyd ook gebruik om na 'n byna optimaleoplossing te streef.

Orientador: Marcio Antonio Cataia / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias / Made available in DSpace on 2018-08-10T06:20:22Z (GMT). No. of bitstreams: 1 Gallo_Fabricio_M.pdf: 2173896 bytes, checksum: 9ac19166951d75b19899220ac4242bec (MD5) Previous issue date: 2006 / Resumo: Este texto apresenta algumas reflexões sobre o uso de pequenas aeronaves na integração e modernização do território brasileiro. O sistema de transporte aéreo, num país de grande extensão territorial, cumpre papel de destaque no estreitamento dos laços regionais e é um elemento de destaque do circuito espacial produtivo da moderna agricultura desenvolvida no Centro-Oeste brasileiro. Agilizando o transporte dos indivíduos e promovendo os contatos face-.a-face, as pequenas aeronaves de rotas não-regulares, em função de sua flexibilidade de deslocamento e de tempo, atuam como vetores fundamentais da integração produtiva do território brasileiro, uma vez que a produção propriamente dita e comando corporativo se dissociaram dadas as possibilidades técnicas do atual período técnico-cientifico e informacional / Abstract: The aim of this text is to make some reflections on the use of small aircrafts for the integration and modernization of the Brazilian territory. The system of air transport, in a country of large territorial extension, is very important to narrow the regional ties and it is an important element of the productive space circuit of the modern agriculture developed in the Brazilian Center-West. The small aircrafts of not-regular routes, act as basic vector of the interactional fluidity, speeding the transport of people, in function of its flexibility of displacement and time, act as basic vector of the productivity integration of the Brazilian territory, a time that the production properly said and corporative command if had separated given to the possibilities techniques of the actual technician-scientific and informacional period / Mestrado / Geografia / Mestre em Geografia

abstract: The objective of this study is to understand how to integrate conical spike external compression inlets with high bypass turbofan engines for application on future supersonic airliners. Many performance problems arise when inlets are matched with engines as inlets come with a plethora of limitations and losses that greatly affect an engine’s ability to operate. These limitations and losses include drag due to inlet spillage, bleed ducts, and bypass doors, as well as the maximum and minimum values of mass flow ratio at each Mach number that define when an engine can no longer function. A collection of tools was developed that allow one to calculate the raw propulsion data of an engine, match the propulsion data with an inlet, calculate the aerodynamic data of an aircraft, and combine the propulsion and aerodynamic data to calculate the installed performance of the entire propulsion system. Several trade studies were performed that tested how changing specific design parameters of the engine affected propulsion performance. These engine trade studies proved that high bypass turbofan engines could be developed with external compression inlets and retain effective supersonic performance. Several engines of efficient fuel consumption and differing bypass ratios were developed through the engine trade studies and used with the aerodynamic data of the Concorde to test the aircraft performance of a supersonic airliner using these engines. It was found that none of the engines that were tested came close to matching the supersonic performance that the Concorde could achieve with its own turbojet engines. It is possible to speculate from the results several different reasons why these turbofan engines were unable to function effectively with the Concorde. These speculations show that more tests and trade studies need to be performed in order to determine if high bypass turbofan engines can be developed for effective usage with supersonic airliners in any possible way. / Dissertation/Thesis / Run file and text files from the propulsion simulations performed in NPSS. / Input and output file used in EDET to generate aerodynamic data of Concorde. / Five column propulsion data of tested engines after inlet matching. / Masters Thesis Aerospace Engineering 2018

The market for large commercial aircraft is in turn dominated by the duopoly of Airbus SAS, a division of EADS, and Boeing Commercial Airplanes, a division of The Boeing Company. My Aim is to describe the current strategic and financial situation of the two largest companies in the aerospace industry with a particular focus on the divisions supplying Large Commercial Aircraft. I describe the production of civil airliners in the whole context of the current global economic situation and the future of aviation. Strategic analysis using methods like PESTLE analysis, PORTER 5F and SWOT focuses mainly on the analysis of macro environment in relation to the companies and aviation business as it is the main driver of aviation expansion. The success of business strategies of both companies will influence the air traffic in the future, determine its nature, quality and availability for customers. Strategic analysis of the intense mutual competition will summarize the main company strategies and their current financial situation. Air traffic development is closely connected to the subject and is also analyzed. Source materials for the analysis are Airbus and Boeing annual reports, public corporate documents, press articles and journals on the topic of aviation and transportation, public IATA reports and other expert studies and forecasts are also used.