| 1. |
- Grönstedt, Tomas, 1970, et al.
(författare)
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Low Pressure System Component Advancements and Its Influence on Future Turbofan Engine Emissions
- 2009
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Ingår i: Proceedings of ASME Turbo Expo 2009: Power for Land, Sea and Air, GT2009.
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Konferensbidrag (refereegranskat)abstract
- Within the European research project EnVIronmenTALly Friendly Aero Engines, VITAL, a number of low pressure system component technologies are being investigated. The emerging progress will allow the design of new power plants providing a step change in engine fuel burn and noise. As part of the VITAL project a Technoeconomic and Environmental Risk Assessment tool, the TERA2020, is being developed. Within this tool, means to assess the impact of component technology progress on the engine/aircraft system level has been implemented. Sensitivities relating parameters traditionally used to describe component performance, such as allowable shaft torque, low pressure turbine stage loading, fan blade weight and system level parameters have been established. This allows a direct assessment of the impact of component research progress on the VITAL power plant CO2 and noise emissions.
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| 2. |
- Abdalla, Alvaro, et al.
(författare)
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The Effect of Engine Dimensions on Supersonic Aircraft Performance
- 2013
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Ingår i: 4:th CEAS Air & Space Conference.
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Konferensbidrag (refereegranskat)abstract
- In aircraft design a critical part of the design isthe engine selection. This is typically making aselection from exiting engines. Looking at a nextgeneration future fighters, however, where thetime of deployment may be 20-30 years in thefuture this is not a valid approach as there willbe an evolution in the engine designs. E.g. anew European fighter aircraft will most likelybe a collaborative project also involving thedevelopment of an engine for that aircraft. Inthis study conceptual engine-airframe co-designis demonstrated, using models of comparablefidelity for both the engine design and theaircraft design. This co-design leads to a deeperunderstanding of the tradeoffs from both sides,and means that also more radical designs andinnovations can be evaluated in a fair way.
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| 3. |
- Abedi, Hamidreza, 1979, et al.
(författare)
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Preliminary Analysis of Compression System Integrated Heat Management Concepts Using LH 2 -Based Parametric Gas Turbine Model
- 2022
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Ingår i: Aerospace. - : MDPI AG. - 2226-4310. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- The investigation of the various heat management concepts using LH2 requires the development of a modeling environment coupling the cryogenic hydrogen fuel system with turbofan performance. This paper presents a numerical framework to model hydrogen-fueled gas turbine engines with a dedicated heat-management system, complemented by an introductory analysis of the impact of using LH2 to precool and intercool in the compression system. The propulsion installations comprise Brayton cycle-based turbofans and first assessments are made on how to use the hydrogen as a heat sink integrated into the compression system. Conceptual tubular compact heat exchanger designs are explored to either precool or intercool the compression system and preheat the fuel to improve the installed performance of the propulsion cycles. The precooler and the intercooler show up to 0.3% improved specific fuel consumption for heat exchanger effectiveness in the range 0.5–0.6, but higher effectiveness designs incur disproportionately higher pressure losses that cancel-out the benefits.
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| 4. |
- Ali, Fakhre, 1986, et al.
(författare)
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A Noise Assessment framework for Subsonic Aircraft and Engines
- 2016
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Ingår i: ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, GT 2016; Seoul; South Korea. - 9780791849682 ; vol 1
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a preliminary subsonic aircraft and engine noise assessment framework, capable of computing the aircraft total noise level at all three certification points (i.e. Approach, Lateral, and Flyover) defined by the International Civil Aviation Organisation. The proposed framework is numerically integrated to account for the complete aircraft noise sources (i.e. the fuselage, wings, landing gear, as well as noise sources resulting from the engine component level, (i.e. fan, compressor, combustor, turbine, and jet). The developed framework is based on a wide-range of empirical and semi-empirical correlations collected from the public domain literature. The fidelity of the framework also caters for flight effects such as atmospheric attenuation, spherical spreading, Doppler shift, lateral attenuation, retarded time and ground reflection. A conversion between the sound pressure level SPL [SPLdB] to effective perceived noise level EPNL [EPNdB] is also included to allow for a consistent comparison with the certification procedure.Through the successful deployment of the proposed framework a generic aircraft model, representative of a modern commercial carrier aircraft has been investigated, operating under representative operational conditions. The sound pressure level corresponding to various aircraft and engine component have been thoroughly investigated and verified with trends acquired based on the theory. Furthermore, the predictions made by theframework corresponding to the aforementioned threecertification points have also been verified against the noise level measurements provided by the International Civil Aviation Organization. The results acquired exhibit good correlation against the verification data for total noise levels at the microphones. Furthermore, a component level comparison is also presented which exhibit good agreement with verification data. The deployed methodology can essentially be regarded asan enabling technology to support the effective and efficient implementation of framework(s) (i.e. Technoeconomic, Environmental and Risk Assessment) targeted to evaluate the existing and advanced aircraft and engine architectures in terms of operational performance and environmental impact.
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| 5. |
- Ander, Mats, 1964, et al.
(författare)
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Development, accomplishment and evaluation of a project course in applied mechanics---Lessons learnt
- 2009
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Ingår i: Svenska mekanikdagarna, Södertälje 2009, 15-17-juni, Session 7:4-Utbildning, sid 99 (1 page abstract). ; , s. 99-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Development, accomplishment and evaluation of a project course in applied mechanics---Lessons learnt M. Ander , T. Grönstedt, T. Abrahamsson and G. JohanssonThis presentation concerns teaching and learning from working in projects within the Chalmers Master programme in Solid and fluid mechanics. The academic tradition requires teaching solid and fluid mechanics as separated subjects of applied mechanics. The researchers/teachers and students belonging to either discipline do not meet on daily basis and thus two separate cultures develop; CFD for fluids and FEM for solids.However, in industry today fresh engineers will meet challenges in multidisciplinary problems and they are expected to be able to know how to treat them. As a remedy to better prepare for their engineering profession, a project course in applied mechanics has been developed. The outline of the course follows the CDIO[1] learning approach: Conceive, Design, Implement and Operate. Starting off from back of the envelope calculations, where all students are required to address all disciplines, the project proceeds towards distinct specializations. The students, divided into groups of six to seven members, focus on ‘student specialists’ roles in solid/structural mechanics-FEM, fluid dynamics, and experimental modal analysis EMA, simulating a true multidisciplinary working environment. The projects studied incorporate a fluid structure interaction core problem, but are required to pose challenges within each specialisation. The task is formulated as a competition to find better solutions or as an investigation of existing methods to solve a problem at hand. The examination is based on individual assignments, group work, presentation of a final report and opposition. As resources for analysing the problems, the students have access to wind tunnel testing, EMA-equipment, computer rooms with commercial software for CFD and FEM. This year we have introduced the ANSYS workbench as a common platform for fluid–structure interaction simulations, allowing the teams to work more closely together. The student perspective is dominated by the urge to approach real world problems with industrial tools. A better contact and understanding between students as well as between teachers/researchers in the different disciplines of applied mechanics are achieved by this approach. Some outstanding challenges are the limited time frame of the course, the time consuming communication required within the teachers team and the student frustration arising from having to address open end problems. [1]www.cdio.org
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| 6. |
- Andersson, Josefin, 1994, et al.
(författare)
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Propulsion Installation Modelling for geared Ultra-high bypass ratio engine cycle design
- 2020
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- About 3% of the greenhouse gas emissions in the EU are derived from aviation. By 2020, the global international aviation emissions are assumed to be approximately 70% higher than those in 2005 and a strong continued growth in travel demand is expected at least up until 2035. A radical reduction of emissions have to occur on multiple fronts ranging from incremental improvements of advanced propulsion systems to new fuels and electrification. The desire to get higher efficiencies has contributed to the movement from turbojet engines to today's high bypass ratio turbofan engines. The fuel consumption and propulsive efficiency of turbofan engines are highly dependent on the fan pressure ratio (FPR). Decreasing FPR gives an improved fuel and propulsive efficiency as long as installation losses do not exceed potential benefits. As part of the Clean Sky project IVANHOE, new types of nacelles will be developed to enable installation of propulsion systems with radically increased bypass ratio and reduced FPR. In this work the process of describing and selecting a suitable propulsion system is described. The cycle is defined by a multidisciplinary analysis considering nacelle drag, propulsion system weight and engine performance. Effects of variation in turbine cooling with cycle change and small size turbomachinery efficiency is considered defining the core size and pressure ratio. Variations in installed SFC with fan diameter choice is quantified along a suboptimal line of fan pressure ratio and bypass ratio for a specific optimal overall pressure ratio. The final cycle choice is presented.
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| 7. |
- 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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| 8. |
- Avellan, Rickard, 1976, et al.
(författare)
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AN ASSESSMAn assessment of a turbofan engine using catalytic interturbine combustionENT OF A TURBOFAN ENGINE USING CATALYTIC INTERTURBINE COMBUSTION
- 2009
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Ingår i: 2009 ASME Turbo Expo; Orlando, FL; United States; 8 June 2009 through 12 June 2009. - 9780791848852 ; 2009:GT2009-59950, s. 383-392
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Konferensbidrag (refereegranskat)abstract
- The potential for using catalytic combustion in aero engines is discussed. Some preliminaries relating to NOx formation and material capabilities are analyzed. Various means to integrate catalytic combustors in aero engines are described. In particular, catalytic interturbine combustion is investigated both in terms of technical feasibility and through a preliminary design exercise. A thermodynamic design point study is presented analyzing a configuration with a combustor located concentrically around the engine core receiving pressurized air through an interstage high pressure compressor bleed. A parameter study of the compressor bleed ratio is presented for the configuration. A substantial reduction in NOx emissions at the expense of an increase in mission fuel consumption is observed.
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| 9. |
- Avellan, Rickard, 1976, et al.
(författare)
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Preparing for Proof-of-concept of a Novel Propeller for Open Rotor Engines
- 2015
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Ingår i: ISABE-2015-20097.
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Konferensbidrag (refereegranskat)abstract
- This article describes the development of a novel high-speed propeller concept. Large-scale propeller tests are extremely expensive and thus not appropriate at early R&D development phases. A convenient approach is to use computational methods validated by small-scale tests with propellers manufactured from low-cost materials and rapid manufacturing methods. The present paper is describing this cross validation work explaining differences between numerics and experiments. Preferred materials and manufacturing methods for high-speed future wind tunnel tests are discussed. We also discuss the progress of development of the aerodynamic design of the concept propeller.
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| 10. |
- 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. - 0954-4100 .- 2041-3025. ; 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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