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Modeling contra-rotating turbomachinery components for engine performance simulations / A. Alexiou in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 11 (Novembre 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 11 (Novembre 2012) . - 10 p. Titre : Modeling contra-rotating turbomachinery components for engine performance simulations : the geared turbofan with contra-rotating core case Type de document : texte imprimé Auteurs : A. Alexiou, Auteur ; I. Roumeliotis, Auteur ; N. Aretakis, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : gas turbines Langues : Anglais (eng) Mots-clés : modeling  contra-rotating  turbomachinery  components;  suitably;  aero-engine  core  concepts Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents a method of modeling contra-rotating turbomachinery components for engine performance simulations. The first step is to generate the performance characteristics of such components. In this study, suitably modified one-dimensional mean line codes are used. The characteristics are then converted to three-dimensional tables (maps). Compared to conventional turbomachinery component maps, the speed ratio between the two shafts is included as an additional map parameter and the torque ratio as an additional table. Dedicated component models are then developed that use these maps to simulate design and off-design operation at the component and engine levels. Using this approach, a performance model of a geared turbofan with a contra-rotating core (CRC) is created. This configuration was investigated in the context of the European program “NEW Aero-Engine Core Concepts” (NEWAC). The core consists of a seven-stage compressor and a two-stage turbine without interstage stators and with successive rotors running in the opposite direction through the introduction of a rotating outer spool. Such a configuration results in a reduced parts count, length, weight, and cost of the entire high pressure (HP) system. Additionally, the core efficiency is improved due to reduced cooling air flow requirements. The model is then coupled to an aircraft performance model and a typical mission is carried out. The results are compared against those of a similar configuration employing a conventional core and identical design point performance. For the given aircraft-mission combination and assuming a 10% engine weight saving when using the CRC arrangement over the conventional one, a total fuel burn reduction of 1.1% is predicted. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000011 [...] [article] Modeling contra-rotating turbomachinery components for engine performance simulations : the geared turbofan with contra-rotating core case [texte imprimé] / A. Alexiou, Auteur ; I. Roumeliotis, Auteur ; N. Aretakis, Auteur . - 2012 . - 10 p. gas turbines Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 11 (Novembre 2012) . - 10 p. Mots-clés : modeling  contra-rotating  turbomachinery  components;  suitably;  aero-engine  core  concepts Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents a method of modeling contra-rotating turbomachinery components for engine performance simulations. The first step is to generate the performance characteristics of such components. In this study, suitably modified one-dimensional mean line codes are used. The characteristics are then converted to three-dimensional tables (maps). Compared to conventional turbomachinery component maps, the speed ratio between the two shafts is included as an additional map parameter and the torque ratio as an additional table. Dedicated component models are then developed that use these maps to simulate design and off-design operation at the component and engine levels. Using this approach, a performance model of a geared turbofan with a contra-rotating core (CRC) is created. This configuration was investigated in the context of the European program “NEW Aero-Engine Core Concepts” (NEWAC). The core consists of a seven-stage compressor and a two-stage turbine without interstage stators and with successive rotors running in the opposite direction through the introduction of a rotating outer spool. Such a configuration results in a reduced parts count, length, weight, and cost of the entire high pressure (HP) system. Additionally, the core efficiency is improved due to reduced cooling air flow requirements. The model is then coupled to an aircraft performance model and a typical mission is carried out. The results are compared against those of a similar configuration employing a conventional core and identical design point performance. For the given aircraft-mission combination and assuming a 10% engine weight saving when using the CRC arrangement over the conventional one, a total fuel burn reduction of 1.1% is predicted. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000011 [...]

Performance model “Zooming” for in-depth component fault diagnosis / N. Aretakis in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 3 (Mars 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 3 (Mars 2011) . - 11 p. Titre : Performance model “Zooming” for in-depth component fault diagnosis Type de document : texte imprimé Auteurs : N. Aretakis, Auteur ; I. Roumeliotis, Auteur ; K. Mathioudakis, Auteur Année de publication : 2012 Article en page(s) : 11 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Compressors  Engines  Fault  location  Gas  turbines  Maintenance  engineering Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A method giving the possibility for a more detailed gas path component fault diagnosis by exploiting the “zooming” feature of current performance modeling techniques is presented. A diagnostic engine performance model is the main tool that points to the faulty engine component. A diagnostic component model is then used to identify the fault. The method is demonstrated on the case of compressor faults. A 1D model based on the “stage stacking” approach is used to “zoom” into the compressors, supporting a 0D engine model. A first level diagnosis determines the deviation of overall compressor performance parameters while zooming calculations allow a localization of the faulty stages of a multistage compressor. The possibility to derive more detailed information with no additional measurement data is established by the incorporation of empirical knowledge on the type of faults that are usually encountered in practice. Although the approach is based on known individual diagnostic methods, it is demonstrated that the integrated formulation provides not only higher effectiveness but also additional fault identification capabilities. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Performance model “Zooming” for in-depth component fault diagnosis [texte imprimé] / N. Aretakis, Auteur ; I. Roumeliotis, Auteur ; K. Mathioudakis, Auteur . - 2012 . - 11 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 3 (Mars 2011) . - 11 p. Mots-clés : Compressors  Engines  Fault  location  Gas  turbines  Maintenance  engineering Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A method giving the possibility for a more detailed gas path component fault diagnosis by exploiting the “zooming” feature of current performance modeling techniques is presented. A diagnostic engine performance model is the main tool that points to the faulty engine component. A diagnostic component model is then used to identify the fault. The method is demonstrated on the case of compressor faults. A 1D model based on the “stage stacking” approach is used to “zoom” into the compressors, supporting a 0D engine model. A first level diagnosis determines the deviation of overall compressor performance parameters while zooming calculations allow a localization of the faulty stages of a multistage compressor. The possibility to derive more detailed information with no additional measurement data is established by the incorporation of empirical knowledge on the type of faults that are usually encountered in practice. Although the approach is based on known individual diagnostic methods, it is demonstrated that the integrated formulation provides not only higher effectiveness but also additional fault identification capabilities. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]