Bibliografie tematiche / Lufthansa

Letteratura scientifica selezionata sul tema "Lufthansa"

Autore: Grafiati
Pubblicato: 4 giugno 2021
Ultima modifica: 31 maggio 2022

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Articoli di riviste sul tema "Lufthansa"

1

Klepacki, Bogdan, e Paulina Mindewicz. "The volatility of price offers of passenger airlines on the example of the Warsaw – Brussels route". Ekonomika i Organizacja Logistyki 5, n. 3 (21 dicembre 2020): 93–104. http://dx.doi.org/10.22630/eiol.2020.5.3.24.

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W opracowaniu autorzy podjęli problematykę oferty cenowej czterech przewoźników lotniczych na trasie Warszawa – Bruksela. Było to dwóch przewoźników tradycyjnych (PLL LOT i Lufthansa) oraz dwóch niskokosztowych (Ryanair i Wizz Air). W analizie uwzględniono zmiany cen biletu na lot konkretnego dnia w półrocznym okresie. Stwierdzono zróżnicowaną politykę cenową. Przewoźnicy niskokosztowi oraz Lufthansa zmieniali cenę często, ale w niewielkim zakresie. Z kolei koszt biletu w polskich liniach stopniowo rósł, najszybciej w ostatnim miesiącu przed lotem. W minimalizacji ceny biletu w PLL LOT należało dokonać rezerwacji minimum trzy miesiące przed lotem. Najniższa cena biletu Lufthansy oraz Ryanair wystąpiła na miesiąc przed wyjazdem. Z kolei w Wizz Air cena ostateczna była niższa od zaoferowanej na początku badania.
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Drijber, Berend Jan, e George Dictus. "Lufthansa". Markt en Mededinging 17, n. 1 (febbraio 2014): 28–31. http://dx.doi.org/10.5553/menm/138762362014017001005.

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Strom, Martin. "European Union Competition Law Developments in the Aviation Sector: July to December 2016". Air and Space Law 42, Issue 2 (1 aprile 2017): 215–40. http://dx.doi.org/10.54648/aila2017015.

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The second half of 2016 has seen a myriad of competition law developments relevant to the aviation sector. This article summarizes the main competition law developments over the past six months and provides the reader with greater detail of each of these developments. The European Commission (hereinafter ‘Commission’) began a second consultation on its proposed reform of the 2014 State aid General Block Exemption Regulation. In particular, the proposed reforms would expand the current exemptions and compensation schemes in relation to, for example, small airports. Another major development is the legal challenge brought by Deutsche Lufthansa (hereinafter ‘Lufthansa’) against the Commission’s refusal to grant a partial waiver of the conditions the Commission imposed as part of its approval of Lufthansa’s takeover of Swiss International Airlines in 2005. The unprecedented appeal would, if successful, lift various requirements currently applying to the fares charged by Lufthansa on certain routes. In addition, the Brexit Competition Law Working Group (BCLWG) has published notes of two roundtable discussions on the antitrust and merger issues resulting from the United Kingdom’s (UK) referendum result to leave (‘Brexit’) the European Union (EU). In particular, the BCLWG discussed the implications of Brexit on the ‘one stop shop’ principle, on pan-European investigations and on the possibility of introducing public interest considerations in merger assessments. The UK’s withdrawal from the EU has the potential to effect a seismic change in the general competitive landscape of the UK and more generally across the EU aviation industry.
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Неправська, Наталія. "Lufthansa залишається в Україні". Український туризм, n. 5, вересень - жовтень (2014): 30–31.

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Heising, Ulrich. "Wertorientiertes Investitionscontrolling bei Lufthansa". Controlling und Management 46, S2 (settembre 2002): 31–37. http://dx.doi.org/10.1007/bf03255710.

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Steinke, Karl-Heinz, Ralf Wischmann, Peter Schentler e Matthias Handrich. "Beschaffungscontrolling bei der Deutschen Lufthansa". Controlling 23, n. 11 (2011): 564–71. http://dx.doi.org/10.15358/0935-0381-2011-11-564.

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red. "BG Kliniken kooperieren mit Lufthansa". Orthopädie und Unfallchirurgie 7, n. 2 (aprile 2017): 7. http://dx.doi.org/10.1007/s41785-017-0058-z.

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Sobek, Werner, Hans Georg Reinke e Tobias Berger. "Die neuen Verwaltungsgebäude der Deutschen Lufthansa AG in Frankfurt am Main (Lufthansa Aviation Center)". Beton- und Stahlbetonbau 100, n. 1 (30 dicembre 2004): 75–78. http://dx.doi.org/10.1002/best.200590015.

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Kuran, Muhammed Furkan, e Andrej Novak. "Brief Economic Analysis and Comparison of Turkish Airlines, Lufthansa Group, Air France – KLM". AUTOBUSY – Technika, Eksploatacja, Systemy Transportowe 19, n. 6 (30 giugno 2018): 888–93. http://dx.doi.org/10.24136/atest.2018.196.

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The paper described brief economic analysis and comparison of Turkish Airlines, Lufthansa Group and Air France – KLM. Throughout the economic and commercial development and with disappearance of boundaries between countries is rapidly changing air transport. The transportation and logistics investments and competition between companies and states rapidly increased. Thus, transportation modes developed and changed rapidly as a natural response to development itself. In the paper, we will practice the comparison of two major companies of European Air Freight: Turkish Airlines and Lufthansa.
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DUTTA, SURYA K., MUNMUN DAS GUPTA e V. S. PRASAD. "Impact of AMDAR observations from Lufthansa aircraft on Global Analysis - Forecast System". MAUSAM 61, n. 2 (27 novembre 2021): 213–20. http://dx.doi.org/10.54302/mausam.v61i2.816.

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AMDAR observations from Lufthansa and Lufthansa cargo aircrafts in BUFR format (with header IUADOI EGGR and IUAHOI EGRR) were made available to India Meteorological Department (IMD) and in turn to National Centre for Medium Range Weather Forecasting (NCMRWF) under special arrangement for a period of two weeks w.e.f. 14th May 2008. These data have been assimilated at NCMRWF (National Centre for Medium Range Weather Forecasting) model for the period 14th - 31st May, 2008 to assess its impact on NWP. Use of these observations gave some positive impact on NWP systems.
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Tesi sul tema "Lufthansa"

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Figueiredo, Luís Miguel Rocha Santos Palma de. "Equity research - Deutsche Lufthansa AG". Master's thesis, Instituto Superior de Economia e Gestão, 2016. http://hdl.handle.net/10400.5/12679.

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Mestrado em Finanças
Este projecto contêm uma avaliação detalhada da Deutsche Lufthansa AG, de acordo com o projecto de trabalho final do programa de Mestrado de Finanças do ISEG. Este relatório foi elaborado de acordo com as recomendações do CFA Institute. O motivo pela escolha da empresa deveu-se ao interesse na apresentação da Deutsche Lufthansa na viagem a Frankfurt conduzida pelo Mestrado de Finanças do ISEG e pelo gosto pela indústria aérea no geral. Este relatório foi elaborado de acordo com a informação pública disponível a 23 de Setembro de 2016, qualquer informação ou evento posterior a esta data não foi considerada. O preço-alvo foi obtido utilizando um método de avaliação absoluto, mais especificamente o método dos Fluxos de Caixa Descontados (DCF), complementado por um método de avaliação relativo, mais especificamente, o método dos múltiplos comparáveis. Com um preço-alvo de €14.43 no final de 2016, representando um potencial de valorização de 37.51% face ao preço corrente de €10.49, a nossa recomendação final para a Deutsche Lufthansa AG é de Compra, apesar dos riscos que possam ocorrer como o aumento do preço dos combustíveis ou o aumento do risco de mercado que podem afectar fortemente o preço-alvo. A nossa avaliação de risco estima um risco médio para a empresa.
This project contains a detailed evaluation of Deutsche Lufthansa AG, according to ISEG's Master in Finance final work project. This report was written in accordance with the recommendations of the CFA Institute. The reason for choosing the company was the interest in the presentation of Deutsche Lufthansa on the trip to Frankfurt conducted by ISEG master in finance, and the interest for the airline industry in general. This report was written in accordance with the public information available on September 23th, 2016, any information or event subsequent to this date has not been considered. The target price was obtained using an absolute valuation method, more specifically the method of Discounted Cash Flow (DCF), complemented by a relative valuation method, more specifically, the method of Comparable Multiples. With a price target of €14.43 at the end of 2016, representing an upside potential of 37.51% from the current price of €10.49, our final recommendation for Deutsche Lufthansa AG is to Buy, despite the risks that may occur such as the increase in fuel prices or the increase in the market risk premium that can strongly affect the price target. Our risk assessment estimates a medium risk for the company.
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Wachtmeister, Louise, Emeli Seensalu e Penny Thrane. "Lufthansa Private Jets kundsegmentering i Sverige". Thesis, Stockholm University, School of Business, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6232.

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Syftet med denna uppsats är att undersöka Lufthansa Private Jets verksamhet och marknadsföringsstrategi i Sverige utifrån kundsegmentering. Vi avser att undersöka hur Lufthansa Private Jet utifrån kundsegmentering kan lokalisera och expandera sin målgrupp i Sverige. Vår studie har en kvalitativ ansats. Undersökningen är en fallstudie som genomförts med hjälp av intervjuer med personer med olika anknytning till Lufthansa Private Jets verksamhet. Uppsatsen bygger på teorier och metoder kring kundsegmentering som vi anser relevanta för syftet med uppsatsen. Empirikapitlet innefattar den information vi erhållit genom kvalitativa intervjuer med Lufthansa Private Jet, dess potentiella kunder samt en branschexpert. I Sverige är 80 % av privatjetsresenärerna företag och 20 % är privatpersoner. Troligtvis väljer personer att resa med privatjet därför att det är tidseffektivt och möjliggör arbete under resans gång. Det framgår att man som kund är villig att betala mer för att spara och effektivisera tid. De främsta behoven som Lufthansa Private Jet kan tillgodose hos svenska kunder är tidsbesparing, bekvämlighet, flexibilitet och frihet. Lufthansa Private Jet når på bästa sätt ut till sin målgrupp i Sverige genom att direkt kontakta kunden på ett personligt och förtroendeingivande sätt.

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Bülow, Ingo. "Change Management zwischen Mythos und Sachzwang der Praxis : Aufbau einer praxisgestützten Modellierung unter Berücksichtigung wirtschaftspädagogischer Theorie, veranschaulicht am Praxisfall der selbstinduzierten Veränderung des Einkaufs der Deutschen Lufthansa AG /". Frankfurt am Main [u.a.] : Lang, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014683646&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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Hutchinson, Mark R. (Mark Robert). "Privatization in Germany : the case of Lufthansa". Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/28158.

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Bruch, Heike. "Leaders' action /". St. Gallen, 2001. http://aleph.unisg.ch/hsgscan/hm00132093.pdf.

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Hamacek, Michaela Maria. "Financial Analysis and Company Valuation of Lufthansa Group". Master's thesis, Vysoká škola ekonomická v Praze, 2015. http://www.nusl.cz/ntk/nusl-205452.

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The aim of the thesis is to provide investors and other stakeholders with an approach how to calculate the fair value of a company and its stocks to make an investment decision. As stock market prices are influenced by many events, they rarely reflect the true underlying value of the company. The company investigated in this thesis is the German airline company Lufthansa. A strategic, a financial and a ratio analysis are performed before the fair value is assessed using the discounted cash flow method under three future scenarios. The analyses revealed a possible undervaluation of the company, which led to a buy recommendation for shares of Lufthansa.
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Winkler, Astrid. "Geschäftsprozessmanagement für unterschiedliche Prozesstypen eine Analyse am Fallbeispiel der Lufthansa Cargo AG". Berlin dissertation.de, 2007. http://www.dissertation.de/buch.php3?buch=5112.

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Lohmeier, Victoria, e Simon Hess. "Airline Pricing Strategies : A comparison of German Lufthansa and Scandinavian Airline System". Thesis, Mid Sweden University, Department of Social Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-8521.

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Berger, Lukas. "Entwicklung eines Geschäftsmodells für Very Light Jets am Beispiel der Deutschen Lufthansa". St. Gallen, 2006. http://www.biblio.unisg.ch/org/biblio/edoc.nsf/wwwDisplayIdentifier/02604395001/$FILE/02604395001.pdf.

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Bökli, Ediz. "Herausforderungen einer internationalen Airline in der Akquisition von türkischen Akademikern". Göttingen Sierke, 2009. http://d-nb.info/993544053/04.

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Libri sul tema "Lufthansa"

1

Kunst: Lufthansa Aviation Center = Art. Frankfurt am Main: Revolver, 2007.

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Davies, R. E. G. Lufthansa: An airline and its aircraft. New York: Orion Books, 1989.

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Lufthansa: An airline and its aircraft. New York: Orion Books, 1991.

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Die Geschichte der Lufthansa: Luftfahrtlegende seit 1926. München: GeraMond, 2008.

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Ernst, Max. Max Ernst: Graphik und Bücher : Sammlung Lufthansa. A cura di Spies Werner 1937-, Linke Claudia, Deutsche Lufthansa (1953- ). Kulturförderung. e Württembergischer Kunstverein. Stuttgart: Hatje, 1991.

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Bijutsukan, Shibuya Kuritsu Shōtō. Gendai Doitsu no sobyō: Tokubetsuten Lufthansa korekushon. Tōkyō: Shibuya Kuritsu Shōtō Bijutsukan, 1986.

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Bittner, Werner. Lufthansa im Krieg: Die Jahre 1939-1945. Emmen: Violaero, 2012.

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Frankfurt, MAK, a cura di. Die Schwingen des Kranichs: 50 Jahre Lufthansa design = The wings of the crane : 50 years of Lufthansa design. Stuttgart: Axel Menges, 2005.

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San Francisco (Calif.). Office of the Controller. Audits Division. Airport Commission: Concession audit of Lufthansa German Airlines. San Francisco: Office of the Controller, 2001.

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Neulen, Hans Werner. Deutsche Lufthansa 1939-1945: Der Kranich in Turbulenzen. Lemwerder: Stedinger Verlag, 2003.

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Capitoli di libri sul tema "Lufthansa"

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Dahm, Markus H., e Aaron D. Brückner. "Lufthansa Technik". In Lean Management im Unternehmensalltag, 143–85. Wiesbaden: Springer Fachmedien Wiesbaden, 2017. http://dx.doi.org/10.1007/978-3-658-16815-5_4.

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Sackmann, Sonja A. "Deutsche Lufthansa AG". In Erfolgsfaktor Unternehmenskultur, 73–94. Wiesbaden: Gabler Verlag, 2004. http://dx.doi.org/10.1007/978-3-322-82623-7_3.

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Rühl, Monika, e Jochen Hoffmann. "Situation bei Lufthansa". In Chancengleichheit managen, 71–96. Wiesbaden: Gabler Verlag, 2001. http://dx.doi.org/10.1007/978-3-322-90215-3_6.

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Zillessen, Renate, e Dieter Rahmel. "Deutsche Lufthansa AG". In Umweltsponsoring, 139–51. Wiesbaden: Gabler Verlag, 1991. http://dx.doi.org/10.1007/978-3-322-90933-6_11.

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Dirk, Max-Philip, Leon Guckelberger e Patrick Eschler. "The Lufthansa strikes". In Managing Negotiations, 92–120. London: Routledge, 2021. http://dx.doi.org/10.4324/9781003105428-6.

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Zschocke, Alexander. "Lufthansa Experiences Using Biokerosene". In Biokerosene, 725–40. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53065-8_28.

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Klaffke, Martin. "Fallstudie – Lufthansa New Workspace". In essentials, 39–48. Wiesbaden: Springer Fachmedien Wiesbaden, 2019. http://dx.doi.org/10.1007/978-3-658-24864-2_5.

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Dienel, Hans-Liudger. "Lufthansa: Two German Airlines". In Flying the Flag, 87–125. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26951-8_4.

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Eisenächer, Harald W. "Lufthansa – Excellence in Branding". In Markenmanagement, 819–35. Wiesbaden: Springer Fachmedien Wiesbaden, 2005. http://dx.doi.org/10.1007/978-3-322-84747-8_32.

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Conrady, Roland, e Markus Orth. "Der Lufthansa infoFlyway im Rahmen der Direktvertriebsstrategie der Deutschen Lufthansa AG". In Erfolgreiche Praxisbeispiele im Online Marketing, 23–48. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-97748-0_2.

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Atti di convegni sul tema "Lufthansa"

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Chen, Hong-Mei, Roland Schutz, Rick Kazman e Florian Matthes. "Amazon in the Air: Innovating with Big Data at Lufthansa". In 2016 49th Hawaii International Conference on System Sciences (HICSS). IEEE, 2016. http://dx.doi.org/10.1109/hicss.2016.631.

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Nittinger, Klaus. "50 Years New Lufthansa - 50 years of Aircraft Selection How to Influence the Industry". In 44th AIAA Aerospace Sciences Meeting and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2006. http://dx.doi.org/10.2514/6.2006-4.

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Schaefer, Klaus, e Joerg Heland. "Ground-based aircraft exhaust measurements of a Lufthansa Airbus A340 using FTIR emission spectrometry". In Photonics East (ISAM, VVDC, IEMB), a cura di Wim A. de Groot. SPIE, 1999. http://dx.doi.org/10.1117/12.337461.

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Bauer, Marc, Jens Friedrichs, Detlev Wulff e Christian Werner-Spatz. "Development and Validation of an On-Wing Engine Thrust Measurement System". In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63277.

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Maintenance on aircraft engines is usually performed on an on-condition basis. Monitoring the engine condition during operation is an important prerequisite to provide efficient maintenance. Engine Condition Monitoring (ECM) has thus become a standard procedure during operation. One of the most important parameters, the engine thrust, is not directly measured, however, and can therefore not be monitored, which makes it difficult to distinguish whether deteriorating trends e.g. in fuel comsumption must be attributed to the engine (e.g. due to thermodynamic wear) or to the aircraft (e.g. due to increased drag). Being able to make this distinction would improve troubleshooting and maintenance planning and thus help to reduce the cost of ownership of an aircraft. As part of the research project APOSEM (Advanced Prediction of Severity effects on Engine Maintenance), Lufthansa Technik (LHT) and the Institute of Jet Propulsion and Turbomachinery of Technische Universität Braunschweig develop a method for direct measurement of engine thrust during the operation. In this paper, the design process of the On-Wing (OW) Measurement System is presented, including the validation in labratory tests, the mechanical and thermal calibration as well as the final ground test during an engine test run at LHT test cell and the work on the flight test certification.
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Lück, Sebastian, Stefan Kuntzagk, Guido Doebbener, Andreas Kellersmann, Christoph Bode e Jens Friedrichs. "Accuracy Assessment of Steady and Unsteady Multistage High Pressure Compressor Simulations". In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-91310.

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Abstract In this paper a comparison of the performance parameters and flow characteristics of a mature commercial high bypass engine’s 9-stages high pressure compressor (HPC) with steady-state mixing-plane (RANS) and unsteady RANS (URANS) CFD is carried out. The investigation is based on a numerical model of the CFM56-5C engine’s HPC which is installed on the Airbus A340-300 aircraft. The compressor under investigation features the so called 3D blading which is the first of two performance improvement packages available. An experimental engine of this type equipped with extensive additional instrumentation is in use by Lufthansa Technik to deliver detailed experimental data of the gas path. Experimental results have been discussed in previous works of the authors. In order to provide long-term forecasts of an engine’s state the aforementioned CFD model has been included into a multilevel engine model. To be able to evaluate the significance and applicability of the CFD results into such model, it is of great interest to which extent and level of detail it can deliver accurate performance predictions. From the comparison of both steady-state and unsteady simulation results it is found that overall compressor performance only differs negligibly while stage performance can differ significantly. It is depicted that among the stator vanes of the front stages local supersonic flow and flow separation can occur. These are not captured by the steady-state simulation to the same degree a time resolved simulation does. In rear stages differences fade and unsteady methods tend to predict better stage performance which may be due to favourable effects of rotor-stator interaction.
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Hönen, Herwart T., Christian Werner-Spatz, Angela Giebmanns, Guido Döbbener e Peter Jeschke. "Measurements of the 3D Flow Field Downstream of an Aircraft Engine Fan". In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-27284.

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Flow field measurements have been performed in a jet engine fan. As a part of a sensitivity study on the influence of geometry changes on the performance of the compressor the experiments provide a data base for the verification of extensive numerical simulations covering the fan blades. These investigations help to improve the understanding of how changes in component geometry due to wear affect the engine. The experimental investigations were carried out down-stream of the fan of a jet engine on the test cell at Lufthansa Technik AG. The main focus of the measurements was to provide highly resolved flow field data downstream of the OGV. A pneumatic five-hole probe was applied in order to obtain 3D information of the flow properties. In order to detect and to resolve the wakes of the OGVs and of the midspan shrouds of the rotor blades the measurements had to be performed along the blade height and had to cover more than one OGV spacing. Therefore, it was necessary to position the probe at various radial and circumferential locations. The radial positioning of the probe was performed by a standard traversing unit. The different circumferential locations were achieved by a specially developed traversing mechanism on a modified engine fan case, which allowed a continuous positioning in the range of two OGV spacings. The experiments were carried out for two different operating points of the jet engine. For each of these operating points, the engine was operated with nominal and with increased tip clearance above the fan rotor in order to simulate different wear conditions. The paper explains the necessary modifications to the jet engine and the set up for the experiments. Furthermore, measured results are shown and compared to the results derived from the CFD simulations which were performed prior to the experimental investigations.
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Kuntzagk, Stefan, Jörn Kraft e Ina Esemann. "CFD Analysis of the Combustion Chamber of a Commercial Aircraft Engine of Medium Thrust Class From a Maintenance Perspective". In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63242.

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Abstract (sommario):
The combustion chamber of aircraft engines plays an important role in achieving the optimum performance during an engine overhaul. For long decades, it has been common understanding in the MRO business that a well overhauled compressor and turbine are required to get an engine with low SFC and high EGT margin. In recent work at Lufthansa Technik AG, a comprehensive CFD analysis of the combustion chamber showed that, in contrast to this, small geometrical features influence the mixing process in the combustion chamber and can have an effect on the exit temperature profile. This in turn can reduce the accuracy of the EGT measurement significantly and create measurement errors and misinterpretations of the real engine performance. In order to get insight into the flow topology, a very detailed digital model has been created using scans of the hardware available in the shop. Important geometrical features such as the cooling provisions and swirl creating components have been included in a very detailed manner with an efficient hexahedral mesh. The model includes the HPT vanes and the cooling flow extraction from the secondary cold flow. CFD results have been generated using the flow solver Ansys CFX 17.1, which is able to predict all relevant physical effects such as injection of liquid fuel, evaporation, and combustion of Jet A1 fuel using the Burning-Velocity combustion model. The flow in the combustion chamber shows large natural fluctuations. Subsequently, for each case a transient calculation has been carried out in order to allow an evaluation of the time-averaged flow field. Different geometrical features are investigated to predict the effect of geometry deviations on the exit temperature profile, e.g. the shape and size of the dilution holes. Finally along the example of two CFM56 engines it will be shown how the data obtained by the detailed CFD model is used to optimize work-scoping and maintenance procedures. On the two cases put forward the combination of extended test-cell instrumentation and detailed modeling enabled not only the identification but also the rectification of combustion chamber deviations. This in turn minimized the necessary work, whereas in the past combustion chamber issues often went unnoticed and consequently resulted in extensive additional work.
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8

Hoenen, Herwart T., e Karsten Ellenberger. "Jet Engine Compressor Blade Refurbishment by Application of the Advanced Re-Contouring Process". In ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/gt2003-38721.

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Abstract (sommario):
In modern jet propulsion Systems the core engine has an essential influence on the total engine performance. Especially the high pressure compressor plays an important role in this scheme. Substantial factors here are losses due to tip clearance effects and aerodynamic airfoil quality. During flight Operation the airfoils are subject to wear and tear on the leading edge. These effects cause a shortening of the chord length and the leading edge profiles become deformed. This results in a deterioration of the engine efficiency performance level and a reduced stall margin. The paper deals with the re-contouring of the leading edges of compressor airfoils. Lufthansa Technik AG in cooperation with the Institute of Jet Propulsion and Turbomachinery (RWTH Aachen University) developed a new method for the profile definition for the blade refurbishment. The common procedure of smoothing out the leading edges manually on a wheel grinding machine can not provide a defined contour nor a reproducible result of the overhaul process. In order to achieve optimized flow conditions in the compressor blade rows, suitable leading edge contours have to be defined for the worn airfoils. In an iterative process the flow behavior of these redesigned profiles is checked by numerical flow simulations and the shape of the profiles is improved. The following machining of the new defined leading edge contours is achieved on a grinding station handled by an appropriately programmed robot. Within this Advanced Re-contouring Process (ARP) the worn blades are precision-measured and then provided with an aerodynamically optimized leading edge profile numerically newly developed under computer control. The application of this process enhances the performance and lowers the fuel consumption while prolonging the blades’ service life by 25%. The performance achievable with ARP has been confirmed both through a long term analysis and by a back-to-back comparison test on the engine test stand. For this purpose the stages 3 through 14 of a CF6-50 high pressure compressor were on the one hand fitted with conventionally overhauled blades and on the other with ARP-optimized blades of the same basic geometry. By installing the optimized blades the EGT margin could be increased by 3° to 4° C. This results in an prolongation of the on-wing time by more than 1000 hours.
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9

Melibaeva, Sevara, Joseph Sussman e Travis P. Dunn. "Comparative Study of High-Speed Passenger Rail Deployment in Megaregion Corridors: Current Experiences and Future Opportunities". In 2011 Joint Rail Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/jrc2011-56115.

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Abstract (sommario):
Deployment of high-speed passenger rail services has occurred around the world in densely-populated corridors, often with the effect of either creating or enhancing a unified economic “megaregion” agglomeration. This paper will review the technical characteristics of a variety of megaregion corridors, including Japan (Tokyo-Osaka), France (Paris-Lyon), and Germany (Frankfurt-Cologne), and their economic impacts. There are many lessons to be drawn from the deployment and ongoing operation of high-speed passenger rail service in these corridors for other countries now considering similar projects, such as the US and parts of the European Union. First, we will review three international cases, describing the physical development of each corridor as well as its measured impacts on economic development. In each case, the travel time reductions of the high-speed service transformed the economic boundaries of the urban agglomerations, integrating labor and consumer markets, while often simultaneously raising concerns about the balance of growth within the region. Moreover, high-speed travel within the regions has had important implications for the modes and patterns of travel beyond the region, particularly with respect to long-distance air travel. An example is the code-shared rail-air service between DeutscheBahn and Lufthansa in the Frankfurt-Cologne corridor. Next, we will examine the implications of these international experiences for high-speed rail deployment elsewhere in the world, particularly the US and Portugal, one of the EU countries investing in high-speed rail. Issues considered include the suitability of high-speed passenger rail service in existing megaregions as well as the potential for formation of megaregions in other corridors. By understanding the impact of high-speed passenger service on economic growth, labor markets, urban form, and the regional distribution of economic activity, planners can better anticipate and prepare countermeasures for any negative effects of high-speed rail. Examples of countermeasures include complementary investments in urban and regional transit connections and cooperation with airlines and other transportation service operators. High-speed passenger rail represents a substantial investment whose implementation and ultimate success depends on a wide range of factors. Among them is the ability of planners and decision-makers to make a strong case for the sharing of benefits across a broad geography, both within and beyond the megaregion (and potential megaregion) corridors where service is most likely to be provided. This paper provides some useful lessons based on international experiences.
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