| 1. |
- Abou-Taouk, Abdallah, 1982, et al.
(författare)
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CFD INVESTIGATION OF SWIRL-STABILIZED FLEXI-FUEL BURNER USING METHANE-AIR MIXTURE FOR GAS TURBINES
- 2011
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Ingår i: International Society for Airbreathing Engines, ISABE, Gothenburg, 2011. ; 1, s. 160-172
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Konferensbidrag (refereegranskat)abstract
- Combustion modeling based on a multi-step global reaction mechanism [1] is applied to CFD (Computational Fluid Dynamics) analysis of a scaled swirl-stabilized 4th generation premixed DLE (Dry Low Emission) burner for gas turbines. The flexi-fuel burner consists of a MAIN pre-mixed flame, a premixed PILOT flame and a confined RPL (Rich Pilot Lean) flame. Both steady-state RANS (Reynolds Averaged Navier Stokes) and hybrid URANS/LES (Unsteady RANS/Large Eddy Simulation) results have been computed. The results are compared with high quality experimental data in the form of emission data, PIV (Particle Image Velocimetry) data and OH-PLIF (Planar Laser Induced Fluorescence Imaging) from an atmospheric burner test rig at Lund University [2-3]. There is a good agreement between the CFD simulations and measurements of emissions, velocity field and flame visualization.
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| 2. |
- Almström, Peter, 1972, et al.
(författare)
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Achieving Sustainable Production through Increased Utilization of Production Resources
- 2011
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Ingår i: Proceedings of the 4th Swedish Production Symposium, SPS11, Lund, May 3-5, 2011. ; , s. 398-406
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Konferensbidrag (refereegranskat)abstract
- There seems to be a quite divergent view on sustainable production, mainly based on the perspective applied. From a global perspective, every kind of material consumption and growth is basically unwanted and should be minimized. This reflects in economic sustainability parameters that point towards producing as little as possible and socialparameters pointing at eliminating abuse of human rights etc. On the other hand, international summits on sustainability have stated that it is a human right to have a certain standard of living, which implies increase in production but with less resource consumption. This global perspective is however not very helpful when focusing on more local level, for example Swedish manufacturing industry. To achieve a long-term jobsecurity the manufacturing companies need to be long-term prosperous. Further, to be able to maintain profitability levels, manufacturing companies need to continuouslyincrease productivity. Utilization deals with using production equipment in a cost efficient way and this article will highlight how utilization affects different aspects of sustainable production, the link between utilization and productivity, as well as practical considerations when improving utilization in manufacturing industry.
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| 3. |
- Berntsson Svensson, Richard, et al.
(författare)
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Prioritization of quality requirements : State of practice in eleven companies
- 2011
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Ingår i: 2011 IEEE 19th International Requirements Engineering Conference, RE 2011; Trento; 29 August 2011 through 2 September 2011. - Trento : IEEE. - 9781457709234 ; , s. 69-78, s. 69-78
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Konferensbidrag (refereegranskat)abstract
- Requirements prioritization is recognized as an important but challenging activity in software product development. For a product to be successful, it is crucial to find the right balance among competing quality requirements. Although literature offers many methods for requirements prioritization, the research on prioritization of quality requirements is limited. This study identifies how quality requirements are prioritized in practice at 11 successful companies developing software intensive systems. We found that ad-hoc prioritization and priority grouping of requirements are the dominant methods for prioritizing quality requirements. The results also show that it is common to use customer input as criteria for prioritization but absence of any criteria was also common. The results suggests that quality requirements by default have a lower priority than functional requirements, and that they only get attention in the prioritizing process if decision-makers are dedicated to invest specific time and resources on QR prioritization. The results of this study may help future research on quality requirements to focus investigations on industry-relevant issues.
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| 4. |
- Marcheschi, Elizabeth, 1980
(författare)
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The physical environment of supported housing
- 2011
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Ingår i: Conference for the Centre for Evidence-based Psychosocial Interventions (CEPI), 2011, Malmö, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
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| 6. |
- Sammak, Majed, et al.
(författare)
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Conceptual Design Of A Mid-Sized Semi-Closed Oxy-Fuel Combustion Combined Cycle
- 2011
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Ingår i: Proceedings of the ASME Turbo Expo 2011: Power for Land, Sea and Air, 2011, Vancouver, Canada. ; 4, s. 253-261
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Konferensbidrag (refereegranskat)abstract
- This paper presents the study of a mid-sized semi-closed oxy-fuel combustion combined cycle (SCOC-CC) with net power output around 108 MW. The paper describes not only the power balance and the performance of the SCOC-CC, but also the conceptual design of the SCOC turbine and compressor. A model has been built in the commercial heat and mass balance code IPSEpro to estimate the efficiency of semi-closed dual-pressure oxy-fuel combustion combined cycle using natural gas as a fuel. In order to obtain the real physical properties of the working fluids in IPSEpro, the code was linked to the NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP).The oxy-fuel turbine was modeled with the in-house Lund University package LUAX-T. Important features such as stage loading, loss modeling, cooling and geometric features were included to generate more accurate results. The oxy-fuel compressor has been modeled using a Chalmers university in-house tool for conceptual design of axial compressors. The conceptual design of the SCOC-CC process has a net efficiency of 47 %. The air separation unit and CO2 compression reduce the cycle efficiency by 10 and 2 percentage points, respectively.A single-shaft configuration was selected for the gas turbine simplicity. The rotational speed chosen was 5200 rpm and the turbine was designed with four stages. All stage preliminary design parameters are within ranges of established industrial axial turbine design limits. The main issue is the turbine exit Mach number; the stage must be lightly loaded in terms of pressure ratio to maintain the exit Mach number below 0.6. The compressor is designed with 18 stages. The current value of the product of the annulus area and the blade rotational speed squared (AN2) was calculated and found to be 40*10^6.
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| 7. |
- Stahl, J. E., et al.
(författare)
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Analytical and experimental determination of the Ra surface roughness during turning
- 2011
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Ingår i: Procedia Engineering (1st CIRP Conference on Surface Integrity, CSI 2012; Bremen; 30 January 2012 through 1 February 2012; Code 87787). - : Elsevier BV. - 1877-7058. ; 19, s. 349-356
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Konferensbidrag (refereegranskat)abstract
- In this article an analytical equation for calculating the theoretical arithmetic mean surface roughness, Ra, in the case of turning using a tool with a circular nose radius is presented. The deviation that often occurs between the expected and the obtained surface roughness during these machining operations is investigated. Influence of the minimum chip thickness is discussed especially in regards to the related phenomenon of so called side flow of material on the machined surface. Three different kinds of workpiece materials have been investigated in order to gain a better understanding of their influence on the obtained surface roughness. The obtained results show that the surface roughness could be considered as being inside an interval of two analytically determined Ra-values. © 2012 Published by Elsevier Ltd. Selection and peer-review under responsibility of Prof. E. Brinksmeier.
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