| 1. |
- Grönstedt, Tomas, 1970, et al.
(författare)
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Multidisciplinary assessment of a year 2035 turbofan propulsion system
- 2022
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Ingår i: 33rd Congress of the International Council of the Aeronautical Sciences, ICAS 2022. - : International Council of the Aeronautical Sciences. - 9781713871163 ; 7, s. 4981-4990
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Konferensbidrag (refereegranskat)abstract
- A conceptual design of a year 2035 turbofan is developed and integrated onto a year 2035 aircraft model. The mission performance is evaluated for CO2, noise and NOx and is compared with a notional XWB/A350-model. An OGV heat exchanger is then studied rejecting heat from an electric generator, and its top-level performance is evaluated. The fan, the booster and the low-pressure turbine of the propulsion system are subject to more detailed aero design based on using commercial design tools and CFD-optimization. Booster aerodynamic modelling output is introduced back into the performance model to study the integrated performance of the component. The top-level performance aircraft improvements are compared to top-level-trends and ICAO estimates of technology progress potential, attempting to evaluate whether there is some additional margin for efficiency improvement beyond the ICAO technology predictions for the same time frame.
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| 2. |
- Zhao, Xin, 1986, et al.
(författare)
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Experimental Validation of the Aerodynamic Characteristics of an Aero-engine Intercooler
- 2017
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Ingår i: Journal of Engineering for Gas Turbines and Power. - : ASME International. - 1528-8919 .- 0742-4795. ; 139:5
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Tidskriftsartikel (refereegranskat)abstract
- Porous media model computational fluid dynamics (CFD) is a valuable approach allowing an entire heat exchanger system, including the interactions with its associated installation ducts, to be studied at an affordable computational effort. Previous work of this kind has concentrated on developing the heat transfer and pressure loss characteristics of the porous medium model. Experimental validation has mainly been based on the measurements at the far field from the porous media exit. Detailed near field data are rare. In this paper, the fluid dynamics characteristics of a tubular heat exchanger concept developed for aero-engine intercooling by the authors are presented. Based on a rapid prototype manufactured design, the detailed flow field in the intercooler system is recorded by particle image velocimetry (PIV) and pressure measurements. First, the computational capability of the porous media to predict the flow distribution within the tubular heat transfer units was confirmed. Second, the measurements confirm that the flow topology within the associated ducts can be described well by porous media CFD modeling. More importantly, the aerodynamic characteristics of a number of critical intercooler design choices have been confirmed, namely, an attached flow in the high velocity regions of the in-flow, particularly in the critical region close to the intersection and the in-flow guide vane, a well-distributed flow in the two tube stacks, and an attached flow in the cross-over duct.
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| 3. |
- Amadori, Kristian, et al.
(författare)
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Towards Zero-Emission in Air Transportation in Scandinavia
- 2023
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Ingår i: AIAA SciTech Forum and Exposition, 2023. - Reston, Virginia : American Institute of Aeronautics and Astronautics.
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Konferensbidrag (refereegranskat)abstract
- The Scandinavian region mixes several interesting features. Metropolitan and urban areas with relatively high population density coexist next to vast but sparsely populated areas; modern ground infrastructures connect larger cities, but smaller communities are less efficiently served; geographical hinders such as mountains, jagged coast lines, lakes and the Baltic Sea further complicate transportation across the region. Previous work has studied how the emergence of new eco-friendly air vehicles designed for shorter routes could stimulate efficient and profitable regional operations in Sweden, especially if they leverage currently underutilized and paid-for airports. Using a purposely developed demand model, forecasts were created to study the changes in mode choice as a result of new regional flights between underserved airports. The idea was that the introduction of environmentally-friendly aircraft would enable revitalizing new routes. In the present paper, the work has been further expanded to broaden the perspective beyond the Swedish borders, taking into consideration also neighbouring countries. To achieve this, regional air transportation demand models were needed for both Norway and Finland. Then, a future scenario is considered to investigate how different sustainable aircraft solutions impact the domestic air transportation in the Scandinavian countries, comparing both potential and applicability of adopting Sustainable Air Fuel, electric or hydrogen fuelled propulsion systems.
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| 4. |
- Camilleri, William, et al.
(författare)
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Concept description and assessment of the main features of a geared intercooled reversed flow core engine
- 2015
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Ingår i: Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering. - : SAGE Publications. - 2041-3025 .- 0954-4100. ; 229:9, s. 1631-1639
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Tidskriftsartikel (refereegranskat)abstract
- Intercooled turbofan cycles allow higher overall pressure ratios to be reached which gives rise to improved thermal efficiency. Intercooling also allows core mass flow rate to be reduced which facilitates higher bypass ratios. A new intercooled core concept is proposed in this paper which promises to alleviate limitations identified with previous intercooled turbofan designs. Specifically, these limitations are related to core losses at high overall pressure ratios as well as difficulties with the installation of the intercooler. The main features of the geared intercooled reversed flow core engine are described. These include an intercooled core, a rear-mounted high-pressure spool fitted rearwards of the low-pressure spool as opposed to concentrically as well as a mixed exhaust. In these studies, the geared intercooled reversed flow core engine has been compared with a geared intercooled straight flow core engine with a more conventional core layout. This paper compares the mechanical design of the high-pressure spools and shows how different high-pressure compressor and high-pressure turbine blade heights can affect over-tip leakage losses. In the reversed configuration, the reduction in high-pressure spool mean diameter allows for taller high-pressure compressor and turbine blades to be adopted which reduces over-tip leakage losses. The implication of intercooler sizing and configuration, including the impact of different matrix dimensions, is assessed for the reversed configuration. It was found that a 1-pass intercooler would be more compact although a 2-pass would be less challenging to manufacture. The mixer performance of the reversed configuration was evaluated at different levels of mixing effectiveness. This paper shows that the optimum ratio of total pressure in the mixing plane for the reversed flow core configuration is about 1.02 for a mixing effectiveness of 80%. Lower mixing effectiveness would result in a higher optimum ratio of total pressure in the mixing plane and fan pressure ratio.
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| 5. |
- Hecken, Tobias, et al.
(författare)
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Conceptual Design Studies of “Boosted Turbofan” Configuration for short range
- 2020
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Ingår i: AIAA 2020-0506 Session: Hybrid Electric Aircraft Design Under Clean Sky 2 (LPA WP1.6.1.4). - Reston, Virginia : American Institute of Aeronautics and Astronautics.
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Konferensbidrag (refereegranskat)abstract
- This paper describes the current activities at the German Aerospace Center (DLR) and an associated consortium related to conceptual design studies of an aircraft configuration with hybrid electric propulsion for a typical short range commercial transport mission. The work is implemented in the scope of the European Clean Sky 2 program in the project “Advanced Engine and Aircraft Configurations” (ADEC) and “Turbo electric Aircraft Design Environment” (TRADE). The configuration analyzed incorporates parallel hybrid architecture consisting of gas turbines, electric machines, and batteries that adds electric power to the fans of the engines. A conceptual aircraft sizing workflow built in the DLR’s “Remote Component Environment” (RCE) incorporating tools of DLR that are based on semi-empirical and low level physics based methods. The TRADE consortium developed a simulation and optimization design platform with analysis models of higher fidelity for an aircraft with hybrid electric propulsion architecture. An implementation of the TRADE simulation and optimization design platform into the DLR’s RCE workflow by replacing the DLR models was carried out. The focus of this paper is on the quantitative evaluation of the “Boosted Turbofan” configuration utilizing the resulting workflow. In order to understand the cooperation between the DLR and TRADE consortium, a brief overview of the activities is given. Then the multi-disciplinary overall aircraft sizing workflow for hybrid electric aircraft built in RCE is shown. Hereafter, the simulation and optimization models of the TRADE design platform are described. Subsequently, an overview of the aircraft configuration considered in the scope of this work is given. The design space studies of the “Boosted Turbofan” configuration are presented. Finally, the deviations of the results between the workflows with and without the TRADE modules are discussed.
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| 6. |
- 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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| 7. |
- Ma, Jinchen, et al.
(författare)
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Sulfur fate during in-situ gasification chemical looping combustion (iG-CLC) of coal
- 2021
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 406
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Tidskriftsartikel (refereegranskat)abstract
- Sulfur conversion during in-situ gasification chemical looping combustion (iG-CLC) of coal is consisted by pyrolysis and char gasification. Insight into the fate of sulfur in these two processes is essential for exploring appropriate strategies for sulfur emission control, whereas in most of works the pyrolysis and gasification could not be fully identified. In this case, a two-stage fluidized bed reactor system comprising a lower and a higher reactor was used to generate in-situ and separate gases from pyrolysis and gasification in this work. Sulfurous gases including H2S, COS, CS2 and SO2 were experimentally studied under various conditions by changing operation temperature (T), O/fuel ratio (Φ) and OC reduction degree (XOC), while the solid samples were regularly collected for the characterization using different techniques. It was found that the sol-gel Fe2O3/Al2O3 was a sulfur resistant OC during the iG-CLC process, thus no formation of sulfur components in the material. The values of T and Φ have positive effect on the conversion of sulfurous gases to SO2, whereas a lower XOC value can improve the conversion of H2S. The main components from volatiles (mainly H2S and CS2) and from char (mainly COS) can be effectively converted to SO2 by the OC material. The coal ash exhibited a desulfurization function, as some sulfur contents were retained as CaSO4 during the iG-CLC tests. Finally, the fate of sulfur in coal during iG-CLC was comprehensively mapped, which would be significant for developing strategies for sulfur emission control.
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| 8. |
- Petit, Olivier, 1980, et al.
(författare)
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An outlook for radical aero engine intercooler concepts
- 2016
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Ingår i: Proceedings of ASME Turbo Expo 2016: Turbine Technical Conference and Exposition, Seoul, South Korea, Jun 13-17, 2016. - 9780791849743 ; 3
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Konferensbidrag (refereegranskat)abstract
- A state of the art turbofan engine has an overall efficiency of about 40%, typically composed of a 50% thermal and an 80% propulsive efficiency. Previous studies have estimated that intercooling may improve fuel burn on such an engine with a 3-5% reduction depending on mission length. The intercooled engine benefits stem firstly from a higher Overall Pressure Ratio (OPR) and secondly from a reduced cooling flow need. Both aspects relate to the reduced compressor exit temperature achieved by the intercooler action. A critical aspect of making the intercooler work efficiently is the use of a variable intercooler exhaust nozzle. This allows reducing the heat extracted from the core in cruise operation as well as reducing the irreversibility generated on the intercooler external surface which arises from bypass flow pressure losses. In this respect the improvements, higher OPR and lower cooling flow need, are achieved indirectly and not by directly improving the underlying thermal efficiency. This paper discusses direct methods to further improve the efficiency of intercooled turbofan engines, either by reducing irreversibility generated in the heat exchanger or by using the rejected heat from the intercooler to generate useful power to the aircraft. The performance improvements by using the nacelle wetted surface to replace the conventional intercooler surface is first estimated. The net fuel burn benefit is estimated at 1.6%. As a second option a fuel cooled intercooler configuration, operated during the climb phase, is evaluated providing a net fuel burn reduction of 1.3%. A novel concept that uses the rejected heat to generate additional useful power is then proposed. A secondary cycle able to convert rejected intercooler heat to useful thrust is used to evaluate three possible scenarios. The two first cases investigate the impact of the heat transfer rate on the SFC reduction. As a final consideration the geared intercooled engine cycle is re-optimized to maximize the benefits of the proposed heat recovery system. The maximum SFC improvement for the three cycles is established to 2%, 3.7% and 3%.
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| 9. |
- Sahoo, Smruti, et al.
(författare)
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A Review of Concepts, Benefits, and Challenges for Future Electrical Propulsion-Based Aircraft
- 2020
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Ingår i: Aerospace. - : MDPI AG. - 2226-4310. ; 7:4
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Forskningsöversikt (refereegranskat)abstract
- Electrification of the propulsion system has opened the door to a new paradigm of propulsion system configurations and novel aircraft designs, which was never envisioned before. Despite lofty promises, the concept must overcome the design and sizing challenges to make it realizable. A suitable modeling framework is desired in order to explore the design space at the conceptual level. A greater investment in enabling technologies, and infrastructural developments, is expected to facilitate its successful application in the market. In this review paper, several scholarly articles were surveyed to get an insight into the current landscape of research endeavors and the formulated derivations related to electric aircraft developments. The barriers and the needed future technological development paths are discussed. The paper also includes detailed assessments of the implications and other needs pertaining to future technology, regulation, certification, and infrastructure developments, in order to make the next generation electric aircraft operation commercially worthy.
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| 10. |
- Seitz, Arne, et al.
(författare)
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Proof of concept study for fuselage boundary layer ingesting propulsion
- 2021
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Ingår i: Aerospace. - : MDPI AG. - 2226-4310. ; 8:1, s. 1-65
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Tidskriftsartikel (refereegranskat)abstract
- Key results from the EU H2020 project CENTRELINE are presented. The research activities undertaken to demonstrate the proof of concept (technology readiness level-TRL 3) for the so-called propulsive fuselage concept (PFC) for fuselage wake-filling propulsion integration are discussed. The technology application case in the wide-body market segment is motivated. The developed performance bookkeeping scheme for fuselage boundary layer ingestion (BLI) propulsion integration is reviewed. The results of the 2D aerodynamic shape optimization for the bare PFC configuration are presented. Key findings from the high-fidelity aero-numerical simulation and aerodynamic validation testing, i.e., the overall aircraft wind tunnel and the BLI fan rig test campaigns, are discussed. The design results for the architectural concept, systems integration and electric machinery pre-design for the fuselage fan turbo-electric power train are summarized. The design and performance implications on the main power plants are analyzed. Conceptual design solutions for the mechanical and aerostructural integration of the BLI propulsive device are introduced. Key heuristics deduced for PFC conceptual aircraft design are presented. Assessments of fuel burn, NOx emissions, and noise are presented for the PFC aircraft and benchmarked against advanced conventional technology for an entry-into-service in 2035. The PFC design mission fuel benefit based on 2D optimized PFC aero-shaping is 4.7%.
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