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An integrated approach for the multidisciplinary design of optimum rotorcraft operations / Ioannis Goulos in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 9 (Septembre 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 9 (Septembre 2012) . - 10 p. Titre : An integrated approach for the multidisciplinary design of optimum rotorcraft operations Type de document : texte imprimé Auteurs : Ioannis Goulos, Auteur ; Pachidis, Vassilios, Auteur ; Roberto d'Ippolito, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Optimum  rotorcraft  operations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This work focuses on the development and application of a generic methodology targeting the design of optimum rotorcraft operations in terms of fuel burn, gaseous emissions, and ground noise impact. An integrated tool capable of estimating the performance and emitted noise of any defined rotorcraft configuration within any designated mission has been deployed. A comprehensive and cost-effective optimization strategy has been structured. The methodology has been applied to two generic, baseline missions representative of current rotorcraft operations. Optimally designed operations for fuel burn, gaseous emissions, and ground noise impact have been obtained. A comparative evaluation has been waged between the acquired optimum designs. The respective trade-off arising from the incorporation of flight paths optimized for different objectives has been quantified. Pareto front derived models for fuel burn and emitted noise have been structured for each mission. The Pareto models have been subsequently deployed for the design of operations optimized in a multidisciplinary manner. The results have shown that the proposed methodology is promising with regards to achieving simultaneous reduction in fuel burn, gaseous emissions, and ground noise impact for any defined mission. The obtainable reductions are found to be dependent on the designated mission. Finally, the potential to design optimum operations in a multidisciplinary fashion using only a single design criterion is demonstrated. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000009 [...] [article] An integrated approach for the multidisciplinary design of optimum rotorcraft operations [texte imprimé] / Ioannis Goulos, Auteur ; Pachidis, Vassilios, Auteur ; Roberto d'Ippolito, Auteur . - 2012 . - 10 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 9 (Septembre 2012) . - 10 p. Mots-clés : Optimum  rotorcraft  operations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This work focuses on the development and application of a generic methodology targeting the design of optimum rotorcraft operations in terms of fuel burn, gaseous emissions, and ground noise impact. An integrated tool capable of estimating the performance and emitted noise of any defined rotorcraft configuration within any designated mission has been deployed. A comprehensive and cost-effective optimization strategy has been structured. The methodology has been applied to two generic, baseline missions representative of current rotorcraft operations. Optimally designed operations for fuel burn, gaseous emissions, and ground noise impact have been obtained. A comparative evaluation has been waged between the acquired optimum designs. The respective trade-off arising from the incorporation of flight paths optimized for different objectives has been quantified. Pareto front derived models for fuel burn and emitted noise have been structured for each mission. The Pareto models have been subsequently deployed for the design of operations optimized in a multidisciplinary manner. The results have shown that the proposed methodology is promising with regards to achieving simultaneous reduction in fuel burn, gaseous emissions, and ground noise impact for any defined mission. The obtainable reductions are found to be dependent on the designated mission. Finally, the potential to design optimum operations in a multidisciplinary fashion using only a single design criterion is demonstrated. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000009 [...]

A sub-idle compressor characteristic generation method with enhanced physical background / Zachos, Pavlos K. in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 8 (Août 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 8 (Août 2011) . - 08 p. Titre : A sub-idle compressor characteristic generation method with enhanced physical background Type de document : texte imprimé Auteurs : Zachos, Pavlos K., Auteur ; Aslanidou, Ioanna, Auteur ; Pachidis, Vassilios, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Compressors  Extrapolation  Gas  turbines  Rotors Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Sub-idle is a very challenging operating region as the performance of a gas turbine engine changes significantly compared with design conditions. In addition, the regulations for new and existing engines are becoming stricter and the prediction of engine relight capability is essential. In order to predict the performance of an engine, detailed component maps are required. The data obtained from rig tests are insufficient at low speeds, creating the need for generation of maps within the sub-idle regime. The first step toward this direction is the use of an extrapolation process. This is a purely mathematical process and the results are not usually of sufficient accuracy. In addition, this method does not provide any insight on the physical phenomena governing the operation of the compressor at low speeds. The accuracy of the resulting compressor map can be increased with a better low speed region definition; this can be achieved via the thorough study of a locked rotor compressor, enabling the derivation of the zero rotational speed line and allowing an interpolation process for the generation of the low speed part of the characteristic. In this work, an enhanced sub-idle compressor map generation technique is proposed. The suggested methodology enables the generation of characteristics at far off-design conditions with enhanced physical background. Alternative parameters for map representation are also introduced. Provided that the all the blade rows of the compressor are of known geometry, a numerical analysis is used for the calculation of the characteristic of the half stage and a stage stacking method is employed to create the entire compressor characteristic. This way, the sub-idle region of the map can be calculated through interpolation, which provides a more accurate and predictive technique. Application of the method for compressor map generation showed that the proposed interpolation approach is robust and capable of enhancing any performance simulation tool used for the prediction of transient altitude relight or ground-starting maneuvers. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] A sub-idle compressor characteristic generation method with enhanced physical background [texte imprimé] / Zachos, Pavlos K., Auteur ; Aslanidou, Ioanna, Auteur ; Pachidis, Vassilios, Auteur . - 2011 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 8 (Août 2011) . - 08 p. Mots-clés : Compressors  Extrapolation  Gas  turbines  Rotors Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Sub-idle is a very challenging operating region as the performance of a gas turbine engine changes significantly compared with design conditions. In addition, the regulations for new and existing engines are becoming stricter and the prediction of engine relight capability is essential. In order to predict the performance of an engine, detailed component maps are required. The data obtained from rig tests are insufficient at low speeds, creating the need for generation of maps within the sub-idle regime. The first step toward this direction is the use of an extrapolation process. This is a purely mathematical process and the results are not usually of sufficient accuracy. In addition, this method does not provide any insight on the physical phenomena governing the operation of the compressor at low speeds. The accuracy of the resulting compressor map can be increased with a better low speed region definition; this can be achieved via the thorough study of a locked rotor compressor, enabling the derivation of the zero rotational speed line and allowing an interpolation process for the generation of the low speed part of the characteristic. In this work, an enhanced sub-idle compressor map generation technique is proposed. The suggested methodology enables the generation of characteristics at far off-design conditions with enhanced physical background. Alternative parameters for map representation are also introduced. Provided that the all the blade rows of the compressor are of known geometry, a numerical analysis is used for the calculation of the characteristic of the half stage and a stage stacking method is employed to create the entire compressor characteristic. This way, the sub-idle region of the map can be calculated through interpolation, which provides a more accurate and predictive technique. Application of the method for compressor map generation showed that the proposed interpolation approach is robust and capable of enhancing any performance simulation tool used for the prediction of transient altitude relight or ground-starting maneuvers. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]