| 1. |
- Andersson, Petter, et al.
(författare)
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Demonstrating an approach for multidisciplinary set-based design within an aerospace research project - DEFAINE
- 2022
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Ingår i: ICAS Proceedings. - 2958-4647. ; 2022
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Konferensbidrag (refereegranskat)abstract
- This paper describes an approach for multidisciplinary set based design within an aerospace research project, DEFAINE. The project is a collaboration between the aerospace manufacturing industry, software providers and academia. The aim of the approach is to reduce the number of iterations conducted in a PD project and increase the number of design variants studied. This is expected to provide more innovative and cost efficient solutions.
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| 2. |
- Assato, Marcelo, et al.
(författare)
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PERFORMANCE BENEFITS OF A FAN ON BLADE – FLADE – FOR A VARIABLE CYCLE ENGINE
- 2022
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Ingår i: 33th Congress of the International Council of the Aeronautical Sciences. - 2958-4647. - 9781713871163 - 9781713871163 ; 7, s. 4888-4902
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Konferensbidrag (refereegranskat)abstract
- Variable cycle engines promise to enable adaptive cycles that give close to optimal performance over a wide range of conflicting mission requirements, such as low altitude high speed flight and supercruise still providing excellent range. Modelling such engines pose challenges for general purpose software since variable geometry gas paths modify the underlying set of equations being solved. It is possible to use multiple engine models transferring design data between the models. This, however, creates a high risk for inconsistency and modelling error. It is more attractive if the solutions obtained could be determined using the same model. In this work an in-house software was developed to model an Adaptive Cycle Engine (ACE). This development was used to show how variable cycle mode switches can be integrated into general purpose performance tools. The variable cycle engine uses a FLADE, which is a "fan on blade" component, to extend its range and to provide improved subsonic performance. The individual impact of the components, its effect on propulsion performance parameters and in the engine installation were analyzed as the main results. The contribution from this paper is thus two-fold, firstly the paper goes ahead and proposes new methods for the simulation of mode switching in generic performance tools by introducing dynamic equation systems. Secondly, the paper then studies the FLADE component and its potential performance benefits if added to a conventional turbofan architecture.
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| 3. |
- Jonsson, Isak, 1990, et al.
(författare)
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Effect of heat exchanger integration in aerodynamic optimization of an aggressive S-duct
- 2022
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Ingår i: ICAS PROCEEDINGS. - 2958-4647. ; 7, s. 4920-4928
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Konferensbidrag (refereegranskat)abstract
- Intercooling the core flow in the compression process using bypass air can potentially reduce fuel consumption in commercial aviation. However, one of the critical challenges with intercooling is the installation and weight penalty due to complex ducting and large surface area for air-to-air heat exchangers (HEX). The recent interest in cryogenic hydrogen (LH2) as a potentially carbon-neutral fuel for commercial aviation expands the propulsive system’s design space due to the vastly different fuel properties between classical Jet-A and LH2. Regarding intercooling, LH2 adds a formidable heat sink with a high specific heat capacity and low storage temperature at 20K and, if utilised in the intercooling process, should allow for increased cooling power density with less installation penalties than an air-to-air HEX. Furthermore, the heat is transferred to the fuel instead of ejected into the bypass air which has potential thermodynamical benefits. The HEX can further be synergistically used to radial turn the core flow in the ICD. This paper presents the integration of a compact air-to-LH2 heat exchanger inside the gas path of the intermediate compressor duct (ICD) as the shape of a truncated cone. Axisymmetric numerical simulations areutilised to evaluate the duct performance and optimise hub and shroud lines for minimal pressure drop andoutlet uniformity. The HEX sizing was based on a preliminary system model of an LH2 commercial aviation engine with 70,000 lbs of thrust.
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| 4. |
- Jouannet, Christopher, et al.
(författare)
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SUSTAINABLE AVIATION FOR SWEDEN - TECHNOLOGY & CAPABILITY ASSESSMENT TARGETING 2045
- 2022
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Ingår i: 33rd CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES. - 2958-4647.
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Konferensbidrag (refereegranskat)abstract
- The goal of this project is to analyse the possibilities offered by different technological solutions to achieve zero emission aviation, firstly in the Swedish/Nordic network context and secondly extend this to the European context. This project will investigate the potential and feasibility of new or upgraded aircraft types based on the different technologies mapped from both, various published roadmaps and national expertise from Swedish aerospace universities and companies. This involves developing aircraft conceptual designs studies and trade analysis with regards to different fuel types, propulsion technologies, structure, operations, network and fleet management, and all relevant technologies. The project will, on a common technology basis, analyse a range of zero carbon fuels and associated technologies through operational studies and optimization to accelerate the introduction of fossil free aircraft technology and choosing optimal paths for making aviation sustainable.
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| 5. |
- Tavares Silva, Vinícius, 1991, et al.
(författare)
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MULTIPOINT AERODYNAMIC DESIGN OF A NACELLE FOR AN ELECTRIC FAN
- 2022
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Ingår i: ICAS Proceedings. - 2958-4647.
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Konferensbidrag (refereegranskat)abstract
- Attention to aircraft electrification has been growing quickly since such technology carries the potential of drastically reducing the environmental impact of aviation. This paper describes the re-design of a nacelle for an electric fan, which is developed as part of the EleFanT (Electric Fan Thruster) project. A multipoint nacelle design approach was carried out. Initially the nacelle shapes were optimized for a cruise condition by employing an evolutionary genetic algorithm (GA). The flow field around the nacelles was calculated by conducting 2D axisymmetric computational fluid dynamics (CFD) simulations, and the objective functions were computed by means of thrust and drag bookkeeping. It was found that the optimizer favored two types of nacelle shapes that differed substantially in geometry. The designs were referred to as low spillage and high spillage types. The optimum low spillage and high spillage cases were selected and investigated further by the means of 3D CFD simulations at cruise and at an end of runway takeoff condition, where the nacelle is subjected to high angle of attack. Whilst the low spillage case provided a slightly better performance at cruise, it presented high levels of distortion and boundary layer separation at takeoff, requiring a substantial shape modification. The high spillage case performed well at takeoff; however, supersonic velocities could be observed at the cowling when it was subjected to incoming flow at an angle of attack. Nonetheless, such problem was easily corrected by drooping the inlet. Due to its superior performance at takeoff, the drooped high spillage design type was recommended.
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| 6. |
- Furukawa, Kentaro, et al.
(författare)
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Expression of the yeast aquaporin Aqy2 affects cell surface properties under the control of osmoregulatory and morphogenic signalling pathways.
- 2009
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Ingår i: Molecular microbiology. - : Wiley. - 1365-2958 .- 0950-382X. ; 74:5, s. 1272-86
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Tidskriftsartikel (refereegranskat)abstract
- Aquaporins mediate rapid and selective water transport across biological membranes. The yeast Saccharomyces cerevisiae possesses two aquaporins, Aqy1 and Aqy2. Here, we show that Aqy2 is involved in controlling cell surface properties and that its expression is controlled by osmoregulatory and morphogenic signalling pathways. Deletion of AQY2 results in diminished fluffy colony morphology while overexpression of AQY2 causes strong agar invasion and adherence to plastic surfaces. Hyper-osmotic stress inhibits morphological developments including the above characteristics as well as AQY2 expression through the osmoregulatory Hog1 mitogen-activated protein kinase. Moreover, two pathways known to control morphological developments are involved in regulation of AQY2 expression: the protein kinase A pathway derepresses AQY2 expression through the Sfl1 repressor, and the filamentous growth Kss1 mitogen-activated protein kinase pathway represses AQY2 expression in a Kss1 activity-independent manner. The AQY2 expression pattern resembles in many ways that of MUC1/FLO11, which encodes a cell surface glycoprotein required for morphological developments. Our observations suggest a potential link between aquaporins and cell surface properties, and relate to the proposed role of mammalian aquaporins in tumour cell migration and invasion.
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