| 1. |
- Kyprianidis, Konstantinos, 1984, et al.
(författare)
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Multidisciplinary Analysis of a Geared Fan Intercooled Core Aero-Engine
- 2014
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Ingår i: Journal of Engineering for Gas Turbines and Power. - : ASME International. - 1528-8919 .- 0742-4795. ; 136:1
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Tidskriftsartikel (refereegranskat)abstract
- The reduction of CO2 emissions is strongly linked with the improvement of engine specific fuel consumption, along with the reduction of engine nacelle drag and weight. One alternative design approach to improving specific fuel consumption is to consider a geared fan combined with an increased overall pressure ratio intercooled core performance cycle. The thermal benefits from intercooling have been well documented in the literature. Nevertheless, there is very little information available in the public domain with respect to design space exploration of such an engine concept when combined with a geared fan. The present work uses a multidisciplinary conceptual design tool to analyze the option of an intercooled core geared fan aero engine for long haul applications with a 2020 entry into service technology level assumption. With minimum mission fuel in mind, the results indicate as optimal values a pressure ratio split exponent of 0.38 and an intercooler mass flow ratio of 1.18 at hot-day top of climb conditions. At ISA midcruise conditions a specific thrust of 86 m/s, a jet velocity ratio of 0.83, an intercooler effectiveness of 56%, and an overall pressure ratio value of 76 are likely to be a good choice. A 70,000 lbf intercooled turbofan engine is large enough to make efficient use of an all-axial compression system, particularly within a geared fan configuration, but intercooling is perhaps more likely to be applied to even larger engines. The proposed optimal jet velocity ratio is actually higher than the value one would expect by using standard analytical expressions, primarily because this design variable affects core efficiency at midcruise due to a combination of several different subtle changes to the core cycle and core component efficiencies at this condition. The analytical expressions do not consider changes in core efficiency and the beneficial effect of intercooling on transfer efficiency, nor do they account for losses in the bypass duct and jet pipe, while a relatively detailed engine performance model, such as the one utilized in this study, does. Mission fuel results from a surrogate model are in good agreement with the results obtained from a rubberized-wing aircraft model for some of the design parameters. This indicates that it is possible to replace an aircraft model with specific fuel consumption and weight penalty exchange rates. Nevertheless, drag count exchange rates have to be utilized to properly assess changes in mission fuel for those design parameters that affect nacelle diameter.
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| 2. |
- Landström, Anna, 1990, et al.
(författare)
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A life cycle approach to business performance measurement systems
- 2018
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Ingår i: Procedia Manufacturing. - : Elsevier BV. - 2351-9789. ; 25, s. 126-133, s. 126-133
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Konferensbidrag (refereegranskat)abstract
- Virtually every company has implemented a Business Performance Measurement System (BPMS) with the purpose of monitoring production and business performance and to execute the corporate strategy at all levels in a company. The purpose of this article is to shed light on common pitfalls related to the practical use of BPMS and further to present a life cycle model with the purpose of introducing structured approach to avoiding the pitfalls. The article contributes to further development of the BPMS life cycle concept and practical examples of how it can be used.
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| 3. |
- Kyprianidis, Konstantinos, et al.
(författare)
-
Dynamic performance investigations of a turbojet engine using a cross-application visual oriented platform
- 2008
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Ingår i: Aeronautical Journal. - 0001-9240. ; 112:1129, s. 161-169
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the development of visual oriented tools for the dynamic performance simulation of a turbojet engine using a cross-application approach. In particular, the study focuses on the feasibility of developing simulation models using different programming environments and linking them together using a popular spreadsheet program. As a result of this effort, a low fidelity cycle program has been created, capable of being integrated with other performance models. The amount of laboratory sessions required for student training during an educational procedure, for example for a course in gas turbine performance simulation, is greatly reduced due to the familiarity of most students with the spreadsheet software. The model results have been validated using commercially available gas turbine simulation software and experimental data from open literature. The most important finding of this study is the capability of the program to link to aircraft performance models and predict the transient working line of the engine for various initial conditions in order to dynamically simulate flight phases including take-off and landing.
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| 4. |
- Kyprianidis, Konstantinos, et al.
(författare)
-
Multi-disciplinary Analysis of a Geared Fan Intercooled Core Aero-Engine
- 2013
-
Ingår i: <em><em>Proc. ASME</em>.</em> 55133; Volume 2: Aircraft Engine; Coal, Biomass and Alternative Fuels; Cycle Innovations, V002T07A027. GT2013-95474. - 9780791855133
-
Konferensbidrag (refereegranskat)abstract
- Reduction of CO2 emissions is strongly linked with the improvement of engine specific fuel consumption, as well as the reduction of engine nacelle drag and weight. One alternative design approach to improving specific fuel consumption is to consider a geared fan combined with an increased overall pressure ratio intercooled core performance cycle. Thermal benefits from intercooling have been well documented in the literature. Nevertheless, there is very little information available in the public domain with respect to design space exploration of such an engine concept when combined with a geared fan. The present work uses a multidisciplinary conceptual design tool to analyse the option of an intercooled core geared fan aero engine for long haul applications with a 2020 entry into service technology level assumption.With minimum mission fuel in mind, the results indicate as optimal values a pressure ratio split exponent of 0.38 and an intercooler mass flow ratio just below 1.2 at hot-day top of climb conditions. At ISA mid-cruise conditions a specific thrust of 86m/s, a jet velocity ratio of 0.83, an intercooler effectiveness of 55% and an overall pressure ratio value of 76 are likely to be a good choice. A 70,000lbf intercooled turbofan engine is large enough to make efficient use of an all-axial compression system, particularly within a geared fan configuration, but intercooling is perhaps more likely to be applied to even larger engines.The proposed optimal jet velocity ratio is actually higher than the value one would expect by using standard analytical expressions primarily because this design variable affects core efficiency at mid-cruise due to a combination of several different subtle changes to the core cycle and core component efficiencies at this condition. Analytical expressions do not consider changes in core efficiency and the beneficial effect of intercooling on transfer efficiency, nor account for losses in the bypass duct and jet pipe, whilst a relatively detailed engine performance model such as the one utilised in this study does.Mission fuel results from a surrogate model are in good agreement with the results obtained from a rubberised-wing aircraft model for some of the design parameters. This indicates that it is possible to replace an aircraft model with specific fuel consumption and weight penalty exchange rates. Nevertheless, drag count exchange rates have to be utilised to properly assess changes in mission fuel for those design parameters that affect nacelle diameter.
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| 5. |
- Cunha, Henrique E., et al.
(författare)
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Investigation of the Potential of Gas Turbines for Vehicular Applications
- 2012
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Ingår i: <em><em>Proc. ASME</em>.</em> 44694; Volume 3: Cycle Innovations; Education; Electric Power; Fans and Blowers; Industrial and Cogeneration. GT2012-68402. - 9780791844694 ; , s. 51-64
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Konferensbidrag (refereegranskat)abstract
- Nowadays, the reduction of fuel consumption and pollutant emissions has become a top priority for society and economy. In the past decades, some of the environmental advantages of the gas turbine (such as inherently low CO and unburned HC) have led some car manufacturers to evaluate the potential of this type of engine as prime mover. This paper suggests a strategy to assess the fuel consumption of gas turbines applied in road vehicles. Based on a quasistatic approach, a model was created that can simulate road vehicles powered by gas turbines, and thereafter a comparison was established with reciprocating engines. Within this study, material and turbomachinery technology developments that have taken place in micro gas turbines since the 1960’s have been considered. A 30% efficiency improvement target has been identified with respect to making the gas turbine fuel competitive to a diesel engine powering an SUV. It is the authors’ view that several technologies that could mature sufficiently within the next 10–15 years exist, such as uncooled ceramic turbines. Such technologies could help bridge the fuel efficiency gap in micro gas turbines and make them commercially competitive in the future for low-emissions vehicular applications. Furthermore, the system developed also allows the simulation of hybrid configurations using gas turbines as range extenders, a solution that some car manufacturers consider to be the most promising in the coming years.
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| 6. |
- Sielemann, M., et al.
(författare)
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Multi-point design of parallel hybrid aero engines
- 2020
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Ingår i: AIAA Propulsion and Energy 2020 Forum. - Västerås : Institute of Electrical and Electronics Engineers Inc.. - 9781624106026 ; , s. 1-18
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Konferensbidrag (refereegranskat)abstract
- A parallel hybrid configuration is a feasible means to reduce fuel consumption of gas turbines propelling aircraft. It introduces an electric drive on one of the spools of the gas turbine, typically the low pressure spool. The electric drive is supplied by a battery, which can also be charged when excess power is available (for instance during conditions requiring handling bleed in conventional designs). It also requires a thermal management system to dissipate heat away from electric components. While the scientific literature describes parallel hybrid studies and anticipated benefits assuming various future entry into service dates, there is limited information on the design of the gas turbine component of such a system. For conventional gas turbines, multi-point design schemes are used. This paper describes, in a consistent fashion and based on a formalized notation, how such multi-point design schemes are applied to parallel hybrid aero engines. It interprets published approaches, fills gaps in methodology descriptions with meaningful assumptions and summarizes design intent. It also discusses cycle designs generated by different methodologies based on the same cycle model. Results show that closure equations prescribing boost power can be preferable over closure equations prescribing temperature ratios for uniqueness and engineering intuitiveness while the latter can be beneficial in a second step for design space exploration.
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| 7. |
- Grahn, Sten, et al.
(författare)
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Potential Advantages Using Large Anthropomorphic Robots in Human-robot Collaborative, Hand Guided Assembly
- 2016
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Ingår i: Procedia CIRP. - : Elsevier. - 2212-8271. ; 44, s. 281-286, s. 281-286
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Tidskriftsartikel (refereegranskat)abstract
- Collaborative robot installations often mean man-machine workspace sharing. This mode of operation can lead to reductions of tact time and work space requirements. We have analyzed potential further benefits of man-machine collaboration, where operators and powerful robots share workspace, cooperating when lifting and handling large objects. We found that this mode of operation has the potential to generate economic advantages by reducing the need for manual operators and lifting tools and by offering new opportunities for component logistics.
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| 8. |
- Gopalakrishnan, Maheshwaran, 1987, et al.
(författare)
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Machine criticality assessment for productivity improvement: Smart maintenance decision support
- 2019
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Ingår i: International Journal of Productivity and Performance Management. - : EMERALD GROUP PUBLISHING LTD. - 1741-0401 .- 1758-6658. ; 68:5, s. 858-878
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Tidskriftsartikel (refereegranskat)abstract
- Purpose The purpose of this paper is to increase productivity through smart maintenance planning by including productivity as one of the objectives of the maintenance organization. Therefore, the goals of the paper are to investigate existing machine criticality assessment and identify components of the criticality assessment tool to increase productivity. Design/methodology/approach An embedded multiple case study research design was adopted in this paper. Six different cases were chosen from six different production sites operated by three multi-national manufacturing companies. Data collection was carried out in the form of interviews, focus groups and archival records. More than one source of data was collected in each of the cases. The cases included different production layouts such as machining, assembly and foundry, which ensured data variety. Findings The main finding of the paper is a deeper understanding of how manufacturing companies assess machine criticality and plan maintenance activities. The empirical findings showed that there is a lack of trust regarding existing criticality assessment tools. As a result, necessary changes within the maintenance organizations in order to increase productivity were identified. These are technological advancements, i.e. a dynamic and data-driven approach and organizational changes, i.e. approaching with a systems perspective when performing maintenance prioritization. Originality/value Machine criticality assessment studies are rare, especially empirical research. The originality of this paper lies in the empirical research conducted on smart maintenance planning for productivity improvement. In addition, identifying the components for machine criticality assessment is equally important for research and industries to efficient planning of maintenance activities.
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| 9. |
- Kyprianidis, Konstantinos G.
(författare)
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Multi-Disciplinary Conceptual Design of Future Jet Engine Systems
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis describes various aspects of the development of a multi-disciplinary aero engine conceptual design tool, TERA2020 (Techno-economic, Environmental and Risk Assessment for 2020), based on an explicit algorithm that considers: engine performance, engine aerodynamic and mechanical design, aircraft design and performance, emissions prediction and environmental impact, engine and airframe noise, and production, maintenance and direct operating costs.As part of this research effort, a newly-derived semi-empirical NOx correlation for modern rich-burn single-annular combustors is proposed. The development of a numerical methods library is also presented, including an improved gradient-based algorithm for solving non-linear equation systems. Common assumptions made in thermo-fluid modelling for gas turbines and their effect on caloric properties are investigated, while the impact of uncertainties on performance calculations and emissions predictions at aircraft system level is assessed. Furthermore, accuracy limitations in assessing novel engine core concepts as imposed by current practice in thermo-fluid modelling are identified.The TERA2020 tool is used for quantifying the potential benefits from novel technologies for three low pressure spool turbofan architectures. The impact of failing to deliver specific component technologies is quantified, in terms of power plant noise and CO2 emissions. To address the need for higher engine thermal efficiency, TERA2020 is again utilised; benefits from the potential introduction of heat-exchanged cores in future aero engine designs are explored and a discussion on the main drivers that could support such initiatives is presented. Finally, an intercooled core and conventional core turbofan engine optimisation procedure using TERA2020 is presented. A back-to-back comparison between the two engine configurations is performed and fuel optimal designs for 2020 are proposed.Whilst the detailed publications and the work carried out by the author, in a collaborative effort with other project partners, is presented in the main body of this thesis, it is important to note that this work is supported by 20 conference and journal papers.
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| 10. |
- Xu, Lei, 1988, et al.
(författare)
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Optimization Study of an Intercooled Recuperated Aero-Engine
- 2013
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Ingår i: Journal of Propulsion and Power. - 0748-4658 .- 1533-3876. ; 29:2, s. 424-432
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Tidskriftsartikel (refereegranskat)abstract
- The design space of an intercooled recuperated aero-engine has been explored using detailed engine and aircraft performance, weight, and dimensions modeling. The design parameters of the engine fan, core, intercooler, recuperator, cooling-air ratio, and variable-geometry settings for the low-pressure turbine have been optimized for minimum mission fuel. Analysis shows that the improvement achieved in terms of performance against the datum design can be attributed primarily to an increase in thermal efficiency. A parametric study has also been carried out around the optimal design to understand the impact of the chosen design parameters on mission fuel burn. The study demonstrates in detail the substantially more complex interrelationship that the different fan design parameters have in terms of engine performance compared to what is typical for conventional turbofan designs. Furthermore, the optimal pressure ratio split between the low-pressure compressor and the high-pressure compressor aligns well with a previous analytical study. It is also revealed that the increased amount of cooling air required when a hot bleeding concept is adopted is in fact beneficial for mission fuel burn. Finally, the study concludes that the potential of using variable geometry in the low-pressure turbine for improving fuel burn is limited by the high-pressure turbine blade-metal temperature.Read More: http://arc.aiaa.org/doi/abs/10.2514/1.B34594
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