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- Isikveren, Askin T., 1969-
(författare)
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Quasi-analytical Modelling and Optimisation Techniques for Transport Aircraft Design
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The research work presented here focuses on the subject oftransport aircraft design at the pre-design or conceptuallevel. The primary topics addressed are: (1) generation of avast array of new quasi-analytical expressions to permit aconceptual treatment of commercial and business transportaircraft with adequate sensitivity for more advanced tradestudies; (2) review and adoption of a method to predictstability and control characteristics (using the Mitchellmethod); (3) a study of the relative merits between variousmethods in facilitating an expedient and robust constrainedmulti-objective optimisation result within the context oftraditional conceptual design problems (Genetic Algorithms andNelder-Mead Simplex search); (4) creation of a software packageas a new and unique conceptual tool that permits the generationof design proposals in an accurate yet expeditious manner; and,(5) practical demonstration of the new conceptual designsoftware package by undertaking some actual aircraft designproposals.The design problem is addressed using mostly closed formsolutions but transcendental expressions with much simplifiednumerical scheme algorithms have also been adopted for sake ofaccuracy. Various new models have been proposed for atmosphericproperties, geometry, gas-turbine engine performance, low-speedand high-speed aerodynamic characteristics, minimum controlspeed limited balanced field estimation, asymmetric flight,and, en route performance characteristics including definitionof operationally permissible speed schedules and flighttechniques for payload-range/fixed sector profiles optimised interms of maximum specific air range, minimum fuel, minimumtime, minimum direct operating cost and maximum profit/returnon investment. The work was extended further to include issuesrelating to the impact of vehicular attributes to pricing themarket is willing toabsorb. Useful information regarding howthese individual computational elements of the methodology maybe integrated for the purpose of constructing coherent modularsub-spaces and formulation of a basic inter-disciplinarycoupling is also presented. The mathematical foundationsderived in this work have lead to an array of tangibleconclusions that aid the conceptual designer via implicitguidelines to achieve truly balanced design concepts.In an explicit demonstration of methodology effectivenessand relative simplicity, a software package called QCARD orQuick Conceptual Aircraft Research and Development was createdin the MATLAB environment. The new software system wasdeveloped to assist the designer in predicting, visualising andoptimising conceptual aircraft designs in a much moreinteractive and far-reaching manner than what is afforded withcontemporary applications whilst emphasising speed and economyof effort.The methodology and software was employed for a 19 passengerturbofan commuter transport design using the cost effectiveWilliams International FJ44-2 engines. To complement this, afuselage stretch version of the baseline vehicle designed toaccommodate 31-34 passengers was also undertaken utilising agrowth version of the original FJ44 power plant. The minimumgoal for both of these concepts was to afford unparalleledcomfort through speed and spaciousness with a competitive edgeagainst turboprops in terms of economics and field performance.The final design effort involved proposal of a Trans-Atlantichigh-performance executive transport employing anunconventional Twin Oblique Lifting Surfaces, or, TOLSconfiguration. The intent here was to produce a new super-largebusiness jet able to operate up to low supersonic speeds withfield performance, en route fuel burn efficiency and costcomparable to that of contemporary business aircraft for thismarket segment.Keywords: aircraft, conceptual, design, specifications,atmosphere, geometry, weight, aerodyanmics, propulsion,operational performance, stability and control, constrainedmulti-objective optimisation, computer aided design, regional,business, high-transonic, low-supersonic.
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| 2. |
- Rompokos, Pavlos, et al.
(författare)
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Synergistic technology combinations for future commercial aircraft using liquid hydrogen
- 2020
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Ingår i: Proceedings of the ASME Turbo Expo. ; 3
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Konferensbidrag (refereegranskat)abstract
- Liquid hydrogen (LH2) has long been seen as a technically feasible fuel for a fully sustainable greener aviation future. The low density of the cryogenic fuel would dictate the redesign of commercial aircraft to accommodate the large tanks, which are unlikely to be integrated within the whole internal volume of the wing. In the ENABLEH2 project, the morphological aspects of a LH2 aircraft design are discussed and a methodology for rapid concept comparative assessment is proposed. An exercise is then carried on to down-select short-to-medium range (SMR) and long-range (LR) concepts, able to carry 200 passengers for 3000 nmi and 414 passengers for 7500 nmi respectively. The down-selection process was split into two phases with the first considering 31 potential airframe architectures and 21 propulsion-system arrangements. The second phase made the final down-selections from a short-list of nine integrated design concepts that were ranked according to 34 criteria, relating to operating cost, revenue, noise and safety. Upon completion of the process, a tube and wing design with the tanks integrated into extended wing roots, and a blended-wing-body design were selected as the best candidates for the SMR and LR applications respectively. Both concepts feature distributed propulsion to maximise synergies from integrating the airframe and propulsion systems.
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| 3. |
- Rompokos, Pavlos, et al.
(författare)
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Synergistic technology combinations for future commercial aircraft using liquid hydrogen
- 2021
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Ingår i: Journal of Engineering for Gas Turbines and Power. - : ASME International. - 1528-8919 .- 0742-4795. ; 143:7
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Tidskriftsartikel (refereegranskat)abstract
- Liquid hydrogen (LH2) has long been seen as a technically feasible fuel for a fully sustainable greener aviation future. The low density of the cryogenic fuel would dictate the redesign of commercial aircraft to accommodate the large tanks, which are unlikely to be integrated within the whole internal volume of the wing. In the ENABLEH2 project, the morphological aspects of a LH2 aircraft design are discussed and a methodology for rapid concept comparative assessment is proposed. An exercise is then carried on to down-select short-to-medium range (SMR) and long-range (LR) concepts, able to carry 200 passengers for 3000 nmi and 414 passengers for 7500 nmi, respectively. The downselection process was split into two phases with the first considering 31 potential airframe architectures and 21 propulsion-system arrangements. The second phase made the final down-selections from a short-list of nine integrated design concepts that were ranked according to 34 criteria, relating to operating cost, revenue, noise, and safety. Upon completion of the process, a tube and wing design with the tanks integrated into extended wing roots, and a blended-wing-body design were selected as the best candidates for the SMR and LR applications, respectively. Both concepts feature distributed propulsion to maximize synergies from integrating the airframe and propulsion systems.
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| 4. |
- Sethi, V., et al.
(författare)
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Enabling Cryogenic Hydrogen-Based CO 2 -Free Air Transport: Meeting the demands of zero carbon aviation
- 2022
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Ingår i: IEEE Electrification Magazine. - 2325-5889 .- 2325-5897. ; 10:2, s. 69-81
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Flightpath 2050 from the European Union (EU) sets ambitious targets for reducing the emissions from civil aviation that contribute to climate change. Relative to aircraft in service in year 2000, new aircraft in 2050 are to reduce CO2 emissions by 75% and nitrogen oxide (NOx) emissions by 90% per passenger kilometer flown. While significant improvements in asset management and aircraft and propulsion-system efficiency and are foreseen, it is recognized that the Flightpath 2050 targets will not be met with conventional jet fuel. Furthermore, demands are growing for civil aviation to target zero carbon emissions in line with other transportation sectors rather than relying on offsetting to achieve 'net zero.' A more thorough and rapid greening of the industry is seen to be needed to avoid the potential economic and social damage that would follow from constraining air travel. This requires a paradigm shift in propulsion technologies. Two technologies with potential for radical decarbonization are hydrogen and electrification. Hydrogen in some form seems an inevitable solution for a fully sustainable aviation future. It may be used directly as a fuel or combined with carbon from direct air capture of CO2 or other renewable carbon sources, to synthesize drop-in replacement jet fuels for existing aircraft and engines. As a fuel, pure hydrogen can be provided as a compressed gas, but the weight of the storage bottles limits the practical aircraft ranges to just a few times that is achievable with battery power. For longer ranges, the fuel needs to be stored at lower pressures in much lighter tanks in the form of cryogenic liquid hydrogen (LH2).
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