Documents disponibles écrits par cet auteur

Describing function analysis of limit cycles in a multiple flame combustor / Frédéric Boudy in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 6 (Juin 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 6 (Juin 2011) . - 08 p. Titre : Describing function analysis of limit cycles in a multiple flame combustor Type de document : texte imprimé Auteurs : Frédéric Boudy, Auteur ; Daniel Durox, Auteur ; Thierry Schuller, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Turbines à gaz Langues : Anglais (eng) Mots-clés : Chemically  reactive  flow  Combustion  Flames  Flow  instability  Fluid  oscillations  Functional  analysis  Laminar  flow  Pipe  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A recently developed nonlinear flame describing function (FDF) is used to analyze combustion instabilities in a system where the feeding manifold has a variable size and where the flame is confined by quartz tubes of variable length. Self-sustained combustion oscillations are observed when the geometry is changed. The regimes of oscillation are characterized at the limit cycle and also during the onset of oscillations. The theoretical predictions of the oscillation frequencies and levels are obtained using the FDF. This generalizes the concept of flame transfer function by including dependence on the frequency and level of oscillation. Predictions are compared with experimental results for two different lengths of the confinement tube. These results are, in turn, used to predict most of the experimentally observed phenomena and in particular, the correct oscillation levels and frequencies at limit cycles. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013300 [...] [article] Describing function analysis of limit cycles in a multiple flame combustor [texte imprimé] / Frédéric Boudy, Auteur ; Daniel Durox, Auteur ; Thierry Schuller, Auteur . - 2011 . - 08 p. Turbines à gaz Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 6 (Juin 2011) . - 08 p. Mots-clés : Chemically  reactive  flow  Combustion  Flames  Flow  instability  Fluid  oscillations  Functional  analysis  Laminar  flow  Pipe  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A recently developed nonlinear flame describing function (FDF) is used to analyze combustion instabilities in a system where the feeding manifold has a variable size and where the flame is confined by quartz tubes of variable length. Self-sustained combustion oscillations are observed when the geometry is changed. The regimes of oscillation are characterized at the limit cycle and also during the onset of oscillations. The theoretical predictions of the oscillation frequencies and levels are obtained using the FDF. This generalizes the concept of flame transfer function by including dependence on the frequency and level of oscillation. Predictions are compared with experimental results for two different lengths of the confinement tube. These results are, in turn, used to predict most of the experimentally observed phenomena and in particular, the correct oscillation levels and frequencies at limit cycles. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013300 [...]

A methodology for on the fly acoustic characterization of the feeding line impedances in a turbulent swirled combustor / Lamraoui, A. in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 1 (Janvier 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 1 (Janvier 2011) . - 07 p. Titre : A methodology for on the fly acoustic characterization of the feeding line impedances in a turbulent swirled combustor Type de document : texte imprimé Auteurs : Lamraoui, A., Auteur ; F. Richecoeur, Auteur ; Thierry Schuller, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Acoustic  impedance  Combustion  Combustion  equipment  Mach  number  Microphones  Swirling  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A methodology is proposed to determine on the fly the acoustic impedances at the boundaries of a combustor under operation and without the need for an external forcing device. The methodology is applied hereby to obtain the reflection coefficients of the air and fuel feeding lines supplying a swirled combustor operating in lean conditions and featuring an unstable regime. It is based on a three-microphone technique and uses the combustion roar noise inside the chamber to get estimates of the boundary impedances in the low frequency limit. Conditions under which this method yields reliable results for the reflection coefficient are examined, and a criterion based on the coherence between microphone signals is proposed to determine the frequency bandwidth for impedance reconstruction. The method also takes into account the flow Mach number in the supplying pipes, which can be non-negligible because of their reduced diameter. The technique is validated against data obtained in a dedicated impedance measurement setup equipped with a high-efficiency loudspeaker. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] A methodology for on the fly acoustic characterization of the feeding line impedances in a turbulent swirled combustor [texte imprimé] / Lamraoui, A., Auteur ; F. Richecoeur, Auteur ; Thierry Schuller, Auteur . - 2012 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 1 (Janvier 2011) . - 07 p. Mots-clés : Acoustic  impedance  Combustion  Combustion  equipment  Mach  number  Microphones  Swirling  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A methodology is proposed to determine on the fly the acoustic impedances at the boundaries of a combustor under operation and without the need for an external forcing device. The methodology is applied hereby to obtain the reflection coefficients of the air and fuel feeding lines supplying a swirled combustor operating in lean conditions and featuring an unstable regime. It is based on a three-microphone technique and uses the combustion roar noise inside the chamber to get estimates of the boundary impedances in the low frequency limit. Conditions under which this method yields reliable results for the reflection coefficient are examined, and a criterion based on the coherence between microphone signals is proposed to determine the frequency bandwidth for impedance reconstruction. The method also takes into account the flow Mach number in the supplying pipes, which can be non-negligible because of their reduced diameter. The technique is validated against data obtained in a dedicated impedance measurement setup equipped with a high-efficiency loudspeaker. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]