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FLOX® combustion at high power density and high flame temperatures / Oliver Lammel in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 12 (Décembre 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 12 (Décembre 2010) . - 10 p. Titre : FLOX® combustion at high power density and high flame temperatures Type de document : texte imprimé Auteurs : Oliver Lammel, Auteur ; Harald Schütz, Auteur ; Guido Schmitz, Auteur Année de publication : 2011 Article en page(s) : 10 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Combustion  Flames  Gas  turbines  Reaction  kinetics Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this contribution, an overview of the progress in the design of an enhanced FLOX® burner is given. A fuel flexible burner concept was developed to fulfill the requirements of modern gas turbines: high specific power density, high turbine inlet temperature, and low NOx emissions. The basis for the research work is numerical simulation. With the focus on pollutant emissions, a detailed chemical kinetic mechanism is used in the calculations. A novel mixing control concept, called HiPerMix®, and its application in the FLOX® burner are presented. In view of the desired operational conditions in a gas turbine combustor, this enhanced FLOX® burner was manufactured and experimentally investigated at the DLR test facility. In the present work, experimental and computational results are presented for natural gas and natural gas+hydrogen combustion at gas turbine relevant conditions and high adiabatic flame temperatures (up to Tad=2000 K). The respective power densities are PA=13.3 MW/m2 bar (natural gas (NG)) and PA=14.8 MW/m2 bar (NG+H2), satisfying the demands of a gas turbine combustor. It is demonstrated that the combustion is complete and stable and that the pollutant emissions are very low. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] FLOX® combustion at high power density and high flame temperatures [texte imprimé] / Oliver Lammel, Auteur ; Harald Schütz, Auteur ; Guido Schmitz, Auteur . - 2011 . - 10 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 12 (Décembre 2010) . - 10 p. Mots-clés : Combustion  Flames  Gas  turbines  Reaction  kinetics Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this contribution, an overview of the progress in the design of an enhanced FLOX® burner is given. A fuel flexible burner concept was developed to fulfill the requirements of modern gas turbines: high specific power density, high turbine inlet temperature, and low NOx emissions. The basis for the research work is numerical simulation. With the focus on pollutant emissions, a detailed chemical kinetic mechanism is used in the calculations. A novel mixing control concept, called HiPerMix®, and its application in the FLOX® burner are presented. In view of the desired operational conditions in a gas turbine combustor, this enhanced FLOX® burner was manufactured and experimentally investigated at the DLR test facility. In the present work, experimental and computational results are presented for natural gas and natural gas+hydrogen combustion at gas turbine relevant conditions and high adiabatic flame temperatures (up to Tad=2000 K). The respective power densities are PA=13.3 MW/m2 bar (natural gas (NG)) and PA=14.8 MW/m2 bar (NG+H2), satisfying the demands of a gas turbine combustor. It is demonstrated that the combustion is complete and stable and that the pollutant emissions are very low. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Reaction kinetics of Ni/Sn soldering reaction / Jens Görlich in Acta materialia, Vol. 58 N° 9 (Mai 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 9 (Mai 2010) . - pp. 3187–3197 Titre : Reaction kinetics of Ni/Sn soldering reaction Type de document : texte imprimé Auteurs : Jens Görlich, Auteur ; Dietmar Baither, Auteur ; Guido Schmitz, Auteur Année de publication : 2011 Article en page(s) : pp. 3187–3197 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Phase  transformation  Soldering  reaction  Grain  boundary  diffusion  Grain  boundary  wetting  Intermetallic  compounds Résumé : Soldering between solid Ni and liquid Sn is studied, including late stages of reflow. Only during the very early stages of the process, intermetallic grains grow with a 1/3 power dependence on time. Later, kinetics clearly changes to parabolic growth, but remarkably in two subsequent regimes distinguished by different rate constants. The observed kinetics is discussed with respect to recent flux-driven ripening theory. This theory is only valid, if at all, for short reflows up to about 4 min. Transmission electron microscopy reveals the predicted scallop-like microstructure only at the very beginning. A sponge-like structure of equiaxed grains then develops, triggered by permanent nucleation of new grains at the Ni/Ni3Sn4 interface. Wetting of grain boundaries appears only up to a certain depth in the reaction zone. This remarkable behavior is explained by thermodynamic arguments. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000418 [article] Reaction kinetics of Ni/Sn soldering reaction [texte imprimé] / Jens Görlich, Auteur ; Dietmar Baither, Auteur ; Guido Schmitz, Auteur . - 2011 . - pp. 3187–3197. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 9 (Mai 2010) . - pp. 3187–3197 Mots-clés : Phase  transformation  Soldering  reaction  Grain  boundary  diffusion  Grain  boundary  wetting  Intermetallic  compounds Résumé : Soldering between solid Ni and liquid Sn is studied, including late stages of reflow. Only during the very early stages of the process, intermetallic grains grow with a 1/3 power dependence on time. Later, kinetics clearly changes to parabolic growth, but remarkably in two subsequent regimes distinguished by different rate constants. The observed kinetics is discussed with respect to recent flux-driven ripening theory. This theory is only valid, if at all, for short reflows up to about 4 min. Transmission electron microscopy reveals the predicted scallop-like microstructure only at the very beginning. A sponge-like structure of equiaxed grains then develops, triggered by permanent nucleation of new grains at the Ni/Ni3Sn4 interface. Wetting of grain boundaries appears only up to a certain depth in the reaction zone. This remarkable behavior is explained by thermodynamic arguments. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000418