Dépouillements

Experimental and modeling studies of the oxidation of surrogate bio-aviation fuels / Ida Shafagh in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 11 p. Titre : Experimental and modeling studies of the oxidation of surrogate bio-aviation fuels Type de document : texte imprimé Auteurs : Ida Shafagh, Auteur ; Kevin J. Hughes, Auteur ; Elena Catalanotti, Auteur ; Zhen Liu, Auteur Année de publication : 2012 Article en page(s) : 11 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Aerospace industry Biofuel Oxidation Petrochemicals Sensitivity analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Jet fuels currently in use in the aviation industry are exclusively kerosene-based. However, potential problems regarding security of supply, climate change, and increasing cost are becoming more significant, exacerbated by the rapidly growing demand from the aviation sector. Biofuels are considered one of the most suitable alternatives to petrochemical-based fuels in the aviation industry in the short to medium term, since blends of biofuel and kerosene provide a good balance of properties currently required from an aviation fuel. Experimental studies at a variety of stoichiometries using a flat flame burner with kerosene and kerosene/biofuel blends have been performed with product analysis by gas sampling and laser-induced fluorescence detection of OH, CO, and CO2. These studies have been complemented by modeling using the PREMIX module of Chemkin to provide insights into and to validate combined models describing the oxidation chemistry of surrogate fuels depicting kerosene, fatty acid methyl ester biofuels, and Fischer-Tropsch derived fuels. Sensitivity analysis has identified important reactions within these schemes, which, where appropriate, have been investigated by molecular modeling techniques available within Gaussian 03. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Experimental and modeling studies of the oxidation of surrogate bio-aviation fuels [texte imprimé] / Ida Shafagh, Auteur ; Kevin J. Hughes, Auteur ; Elena Catalanotti, Auteur ; Zhen Liu, Auteur . - 2012 . - 11 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 11 p. Mots-clés : Aerospace industry Biofuel Oxidation Petrochemicals Sensitivity analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Jet fuels currently in use in the aviation industry are exclusively kerosene-based. However, potential problems regarding security of supply, climate change, and increasing cost are becoming more significant, exacerbated by the rapidly growing demand from the aviation sector. Biofuels are considered one of the most suitable alternatives to petrochemical-based fuels in the aviation industry in the short to medium term, since blends of biofuel and kerosene provide a good balance of properties currently required from an aviation fuel. Experimental studies at a variety of stoichiometries using a flat flame burner with kerosene and kerosene/biofuel blends have been performed with product analysis by gas sampling and laser-induced fluorescence detection of OH, CO, and CO2. These studies have been complemented by modeling using the PREMIX module of Chemkin to provide insights into and to validate combined models describing the oxidation chemistry of surrogate fuels depicting kerosene, fatty acid methyl ester biofuels, and Fischer-Tropsch derived fuels. Sensitivity analysis has identified important reactions within these schemes, which, where appropriate, have been investigated by molecular modeling techniques available within Gaussian 03. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

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Autoignition limits of hydrogen at relevant reheat combustor operating conditions / J. Fleck in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 08 p. Titre : Autoignition limits of hydrogen at relevant reheat combustor operating conditions Type de document : texte imprimé Auteurs : J. Fleck, Auteur ; P. Griebel, Auteur ; A.M. Steinberg, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Combustion Gas turbines Hydrogen Ignition Velocity measurement Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The use of highly reactive fuels in the lean premixed combustion systems employed in stationary gas turbines can lead to many practical problems, such as unwanted autoignition in regions not designed for combustion. In the present study, autoignition characteristics for hydrogen, diluted with up to 30 vol. % nitrogen, were investigated at conditions relevant to reheat combustor operation (p = 15 bar, T >1000 K, hot flue gas, relevant residence times). The experiments were performed in a generic, optically accessible reheat combustor, by applying high-speed imaging and particle image velocimetry. Autoignition limits for different mixing section (temperature, velocity) and fuel jet (N2 dilution) parameters are described. The dominant factor influencing autoignition was the temperature, with an increase of around 2% leading to a reduction of the highest possible H2 concentration without “flame-stabilizing autoignition kernels” of approximately 16 vol. %. Furthermore, the onset and propagation of the ignition kernels were elucidated using the high-speed measurements. It was found that the ability of individual autoignition kernels to develop into stable flames depends on the initial position of the kernel and the corresponding axial velocity at that position. While unwanted autoignition occurred prior to reaching the desired operating point for most investigated conditions, for certain conditions the reheat combustor could be operated stably with up to 80 vol. % H2 in the fuel. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Autoignition limits of hydrogen at relevant reheat combustor operating conditions [texte imprimé] / J. Fleck, Auteur ; P. Griebel, Auteur ; A.M. Steinberg, Auteur . - 2012 . - 08 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 08 p. Mots-clés : Combustion Gas turbines Hydrogen Ignition Velocity measurement Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The use of highly reactive fuels in the lean premixed combustion systems employed in stationary gas turbines can lead to many practical problems, such as unwanted autoignition in regions not designed for combustion. In the present study, autoignition characteristics for hydrogen, diluted with up to 30 vol. % nitrogen, were investigated at conditions relevant to reheat combustor operation (p = 15 bar, T >1000 K, hot flue gas, relevant residence times). The experiments were performed in a generic, optically accessible reheat combustor, by applying high-speed imaging and particle image velocimetry. Autoignition limits for different mixing section (temperature, velocity) and fuel jet (N2 dilution) parameters are described. The dominant factor influencing autoignition was the temperature, with an increase of around 2% leading to a reduction of the highest possible H2 concentration without “flame-stabilizing autoignition kernels” of approximately 16 vol. %. Furthermore, the onset and propagation of the ignition kernels were elucidated using the high-speed measurements. It was found that the ability of individual autoignition kernels to develop into stable flames depends on the initial position of the kernel and the corresponding axial velocity at that position. While unwanted autoignition occurred prior to reaching the desired operating point for most investigated conditions, for certain conditions the reheat combustor could be operated stably with up to 80 vol. % H2 in the fuel. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

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A comparative study of flamelet and finite rate chemistry LES for a swirl stabilized flame / C. Fureby in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 13 p. Titre : A comparative study of flamelet and finite rate chemistry LES for a swirl stabilized flame Type de document : texte imprimé Auteurs : C. Fureby, Auteur Année de publication : 2012 Article en page(s) : 13 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Chemically reactive flow Combustion equipment Flames Flow instability simulation Gas turbines Swirling Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Present-day demands on combustion equipment are increasing the need for improved understanding and prediction of turbulent combustion. Large eddy simulation (LES), in which the large-scale flow is resolved on the grid, leaving only the small-scale flow to be modeled, provides a natural framework for combustion simulations as the transient nature of the flow is resolved. In most situations; however, the flame is thinner than the LES grid, and subgrid modeling is required to handle the turbulence-chemistry interaction. Here we examine the predictive capabilities between LES flamelet models, such as the flamelet progress variable (LES-FPV) model, and LES finite rate chemistry models, such as the thickened flame model (LES-TFM), the eddy dissipation concept (LES-EDC) model, and the partially stirred reactor model (LES-PaSR). The different models are here used to examine a swirl-stabilized premixed flame in a laboratory gas turbine combustor, featuring the triple annular research swirler (TARS), for which high-quality experimental data is available. The comparisons include velocity and temperature profiles as well as combustor dynamics and NO formation. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] A comparative study of flamelet and finite rate chemistry LES for a swirl stabilized flame [texte imprimé] / C. Fureby, Auteur . - 2012 . - 13 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 13 p. Mots-clés : Chemically reactive flow Combustion equipment Flames Flow instability simulation Gas turbines Swirling Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Present-day demands on combustion equipment are increasing the need for improved understanding and prediction of turbulent combustion. Large eddy simulation (LES), in which the large-scale flow is resolved on the grid, leaving only the small-scale flow to be modeled, provides a natural framework for combustion simulations as the transient nature of the flow is resolved. In most situations; however, the flame is thinner than the LES grid, and subgrid modeling is required to handle the turbulence-chemistry interaction. Here we examine the predictive capabilities between LES flamelet models, such as the flamelet progress variable (LES-FPV) model, and LES finite rate chemistry models, such as the thickened flame model (LES-TFM), the eddy dissipation concept (LES-EDC) model, and the partially stirred reactor model (LES-PaSR). The different models are here used to examine a swirl-stabilized premixed flame in a laboratory gas turbine combustor, featuring the triple annular research swirler (TARS), for which high-quality experimental data is available. The comparisons include velocity and temperature profiles as well as combustor dynamics and NO formation. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

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Numerical simulations of turbulent mixing and autoignition of hydrogen fuel at reheat combustor operating conditions / Elizaveta M. Ivanova in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 07 p. Titre : Numerical simulations of turbulent mixing and autoignition of hydrogen fuel at reheat combustor operating conditions Type de document : texte imprimé Auteurs : Elizaveta M. Ivanova, Auteur ; Berthold E. Noll, Auteur ; Peter Griebel, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Flow simulation Ignition Navier-Stokes equations Numerical analysis Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Turbulent mixing and autoignition of H2-rich fuels at relevant reheat combustor operating conditions are investigated in the present numerical study. The flow configuration under consideration is a fuel jet perpendicularly injected into a crossflow of hot flue gas (T>1000K,p=15 bar). Based on the results of the experimental study for the same flow configuration and operating conditions, two different fuel blends are chosen for the numerical simulations. The first fuel blend is a H2/natural gas/N2 mixture at which no autoignition events were observed in the experiments. The second fuel blend is a H2/N2 mixture at which autoignition in the mixing section occurred. First, the non-reacting flow simulations are performed for the H2/natural gas/N2 mixture in order to compare the accuracy of different turbulence modeling methods. Here, the steady-state Reynolds-averaged Navier- Stokes (RANS) as well as the unsteady scale-adaptive simulation (SAS) turbulence modeling methods are applied. The velocity fields obtained in both simulations are directly validated against experimental data. The SAS method shows better agreement with the experimental results. In the second part of the present work, the autoignition of the H2/N2 mixture is numerically studied using the 9-species 21-steps reaction mechanism of O'Conaire et al. (Int. J. Chem. Kinet., 36(11), 2004). As in the reference experiments, autoignition can be observed in the simulations. Influences of the turbulence modeling as well as of the hot flue gas temperature are investigated. The onset and the propagation of the ignition kernels are studied based on the SAS modeling results. The obtained numerical results are discussed and compared with data from experimental autoignition studies. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Numerical simulations of turbulent mixing and autoignition of hydrogen fuel at reheat combustor operating conditions [texte imprimé] / Elizaveta M. Ivanova, Auteur ; Berthold E. Noll, Auteur ; Peter Griebel, Auteur . - 2012 . - 07 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 07 p. Mots-clés : Flow simulation Ignition Navier-Stokes equations Numerical analysis Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Turbulent mixing and autoignition of H2-rich fuels at relevant reheat combustor operating conditions are investigated in the present numerical study. The flow configuration under consideration is a fuel jet perpendicularly injected into a crossflow of hot flue gas (T>1000K,p=15 bar). Based on the results of the experimental study for the same flow configuration and operating conditions, two different fuel blends are chosen for the numerical simulations. The first fuel blend is a H2/natural gas/N2 mixture at which no autoignition events were observed in the experiments. The second fuel blend is a H2/N2 mixture at which autoignition in the mixing section occurred. First, the non-reacting flow simulations are performed for the H2/natural gas/N2 mixture in order to compare the accuracy of different turbulence modeling methods. Here, the steady-state Reynolds-averaged Navier- Stokes (RANS) as well as the unsteady scale-adaptive simulation (SAS) turbulence modeling methods are applied. The velocity fields obtained in both simulations are directly validated against experimental data. The SAS method shows better agreement with the experimental results. In the second part of the present work, the autoignition of the H2/N2 mixture is numerically studied using the 9-species 21-steps reaction mechanism of O'Conaire et al. (Int. J. Chem. Kinet., 36(11), 2004). As in the reference experiments, autoignition can be observed in the simulations. Influences of the turbulence modeling as well as of the hot flue gas temperature are investigated. The onset and the propagation of the ignition kernels are studied based on the SAS modeling results. The obtained numerical results are discussed and compared with data from experimental autoignition studies. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

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Experimental investigation on the effects of a large recirculating area on the performance of an effusion cooled combustor liner / Lorenzo Tarchi in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 09 p. Titre : Experimental investigation on the effects of a large recirculating area on the performance of an effusion cooled combustor liner Type de document : texte imprimé Auteurs : Lorenzo Tarchi, Auteur ; Facchini, Bruno, Auteur ; Francesco Maiuolo, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Combustion Engines Finite element analysis Heat transfer Thermo-optical effects Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An experimental analysis of a realistic engine cooling scheme was performed on a test article replicating a slot injection and an effusion array with a central large dilution hole. A test section consists of a rectangular cross-section duct with a flat plate comprised of 270 effusion holes arranged in 29 staggered rows (D = 1.65 mm, Sx/D = 7.6, Sy/D = 6, L/D = 5.5, alpha = 30 deg) and a dilution hole (D = 18.75 mm) located at the 14th row. Both effusion and dilution holes are fed by a channel replicating a combustor annulus, which allows to control of cold gas side cross-flow parameters, especially in terms of Reynolds number of both annulus and effusion holes. Upstream the first row, a 6 mm high slot ensures the protection of the very first region of the liner. In order to simulate the combustor flowpath, a backward facing step was installed upstream the slot to generate a large recirculating area. Adiabatic effectiveness, heat transfer coefficient and net heat flux reduction were evaluated and compared with non- recirculating experiments. Measurements were performed by means of a steady-state Thermochromic liquid crystals (TLC) technique with a thin Inconel heating foil for the heat transfer measurements. A data reduction procedure based on a finite element approach has been developed to take into account the non uniform heat generation and conduction due to the large amount of holes. Experiments were carried out considering the combined effects of slot, effusion and dilution holes. Three different effusion blowing ratios (BR = 3-5-7) are investigated, keeping constant the slot flow parameters (BR = 1.3). Results highlight that the presence of the step leads to a general reduction of effectiveness while does not have effects on the heat transfer coefficient. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Experimental investigation on the effects of a large recirculating area on the performance of an effusion cooled combustor liner [texte imprimé] / Lorenzo Tarchi, Auteur ; Facchini, Bruno, Auteur ; Francesco Maiuolo, Auteur . - 2012 . - 09 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 09 p. Mots-clés : Combustion Engines Finite element analysis Heat transfer Thermo-optical effects Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An experimental analysis of a realistic engine cooling scheme was performed on a test article replicating a slot injection and an effusion array with a central large dilution hole. A test section consists of a rectangular cross-section duct with a flat plate comprised of 270 effusion holes arranged in 29 staggered rows (D = 1.65 mm, Sx/D = 7.6, Sy/D = 6, L/D = 5.5, alpha = 30 deg) and a dilution hole (D = 18.75 mm) located at the 14th row. Both effusion and dilution holes are fed by a channel replicating a combustor annulus, which allows to control of cold gas side cross-flow parameters, especially in terms of Reynolds number of both annulus and effusion holes. Upstream the first row, a 6 mm high slot ensures the protection of the very first region of the liner. In order to simulate the combustor flowpath, a backward facing step was installed upstream the slot to generate a large recirculating area. Adiabatic effectiveness, heat transfer coefficient and net heat flux reduction were evaluated and compared with non- recirculating experiments. Measurements were performed by means of a steady-state Thermochromic liquid crystals (TLC) technique with a thin Inconel heating foil for the heat transfer measurements. A data reduction procedure based on a finite element approach has been developed to take into account the non uniform heat generation and conduction due to the large amount of holes. Experiments were carried out considering the combined effects of slot, effusion and dilution holes. Three different effusion blowing ratios (BR = 3-5-7) are investigated, keeping constant the slot flow parameters (BR = 1.3). Results highlight that the presence of the step leads to a general reduction of effectiveness while does not have effects on the heat transfer coefficient. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

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Experimental analysis of confined jet flames by laser measurement techniques / Oliver Lammel in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 09 p. Titre : Experimental analysis of confined jet flames by laser measurement techniques Type de document : texte imprimé Auteurs : Oliver Lammel, Auteur ; Michael Stöhr, Auteur ; Peter Kutne, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Chemiluminescence Combustion Flames Fluorescence Gas turbines Jets Nozzles Organic compounds Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An experimental analysis of confined premixed turbulent methane/air and hydrogen/air jet flames is presented. A generic lab scale burner for high-velocity preheated jets equipped with an optical combustion chamber was designed and set up. The size and operating conditions were configured to enable flame stabilization by recirculation of hot combustion products. The geometry of the rectangular confinement and an off-center positioning of the jet nozzle were chosen to resemble one burner nozzle of a FLOX®-based combustor. The off-center jet arrangement caused the formation of a pronounced lateral recirculation zone similar to the one in previously investigated FLOX®-combustors (Lückerath et al., 2007. “FLOX® Combustion at High Pressure with Different Fuel Compositions,” ASME J. Eng. Gas Turbines Power, 130(1), pp. 011505; Lammel et al., 2010. “FLOX® Combustion at High Power Density and High Flame Temperatures,” ASME J. Eng. Gas Turbines Power, 132(12), p. 121503ff). The analysis was accomplished by different laser measurement techniques. Flame structures were visualized by OH* chemiluminescence imaging and planar laser-induced fluorescence of the OH radical. Laser Raman scattering was used to determine concentrations of the major species and the temperature. Velocity fields were measured with particle image velocimetry. Results of measurements in two confined jet flames are shown. The mixing of fresh gas with recirculating combustion products and the stabilization of the methane flame are discussed in detail. The presented findings deliver important information for the understanding of confined jet flames operated with different fuels. The obtained data sets can be used for the validation of numerical simulations as well. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Experimental analysis of confined jet flames by laser measurement techniques [texte imprimé] / Oliver Lammel, Auteur ; Michael Stöhr, Auteur ; Peter Kutne, Auteur . - 2012 . - 09 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 09 p. Mots-clés : Chemiluminescence Combustion Flames Fluorescence Gas turbines Jets Nozzles Organic compounds Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An experimental analysis of confined premixed turbulent methane/air and hydrogen/air jet flames is presented. A generic lab scale burner for high-velocity preheated jets equipped with an optical combustion chamber was designed and set up. The size and operating conditions were configured to enable flame stabilization by recirculation of hot combustion products. The geometry of the rectangular confinement and an off-center positioning of the jet nozzle were chosen to resemble one burner nozzle of a FLOX®-based combustor. The off-center jet arrangement caused the formation of a pronounced lateral recirculation zone similar to the one in previously investigated FLOX®-combustors (Lückerath et al., 2007. “FLOX® Combustion at High Pressure with Different Fuel Compositions,” ASME J. Eng. Gas Turbines Power, 130(1), pp. 011505; Lammel et al., 2010. “FLOX® Combustion at High Power Density and High Flame Temperatures,” ASME J. Eng. Gas Turbines Power, 132(12), p. 121503ff). The analysis was accomplished by different laser measurement techniques. Flame structures were visualized by OH* chemiluminescence imaging and planar laser-induced fluorescence of the OH radical. Laser Raman scattering was used to determine concentrations of the major species and the temperature. Velocity fields were measured with particle image velocimetry. Results of measurements in two confined jet flames are shown. The mixing of fresh gas with recirculating combustion products and the stabilization of the methane flame are discussed in detail. The presented findings deliver important information for the understanding of confined jet flames operated with different fuels. The obtained data sets can be used for the validation of numerical simulations as well. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

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An experimental study of lean blowout with hydrogen-enriched fuels / Shengrong Zhu in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 10 p. Titre : An experimental study of lean blowout with hydrogen-enriched fuels Type de document : texte imprimé Auteurs : Shengrong Zhu, Auteur ; Sumanta Acharya, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Chemiluminescence Flames Fuel Hydrogen Nitrogen compounds Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Lean premixed combustion is widely used to achieve a better compromise between nitric oxide (NOx) emissions and combustion efficiency (related to CO levels). However, combustor operation near the lean blowout (LBO) limit can render the flame unstable and lead to oscillations, flashback, or extinction, thereby limiting the potential range of lean combustion application. Recent interest in integrated gasification combined cycle plants and syngas combustion requires an improved understanding of the role of hydrogen on the combustion process. Therefore, in the present study, combustion of pure methane and blended methane-hydrogen with hydrogen-levels up to 80% by volume has been conducted in a swirl stabilized premixed combustor. Particle imaging velocimetry (PIV) and OH* chemiluminescence imaging have been used in this study. Results show that there is a single-ringed structure of internal recirculation zone (IRZ) in the non-reacting flow, while in the reacting flows, there is a more complex flow pattern with a two-celled IRZ structure in which the axial velocity near the center-axis is oriented downstream. As the equivalence ratio decreases, the width of IRZ decreases in methane flames while it increases in hydrogen-enriched flames, and the flame shape changes from conical to an elongated columnar shape, especially in hydrogen-enriched flames. There are two different modes of vortex breakdown observed, spiral mode in methane flames and bubble mode in hydrogen-enriched flames. These differences between the behavior of the methane-only and hydrogen-enriched flames lead to different behavior of the flame as it approaches the lean blowout. The differences in the mechanisms of LBO in pure methane and hydrogen-enriched premixed flames are examined and explained in the present study. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] An experimental study of lean blowout with hydrogen-enriched fuels [texte imprimé] / Shengrong Zhu, Auteur ; Sumanta Acharya, 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° 4 (Avril 2012) . - 10 p. Mots-clés : Chemiluminescence Flames Fuel Hydrogen Nitrogen compounds Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Lean premixed combustion is widely used to achieve a better compromise between nitric oxide (NOx) emissions and combustion efficiency (related to CO levels). However, combustor operation near the lean blowout (LBO) limit can render the flame unstable and lead to oscillations, flashback, or extinction, thereby limiting the potential range of lean combustion application. Recent interest in integrated gasification combined cycle plants and syngas combustion requires an improved understanding of the role of hydrogen on the combustion process. Therefore, in the present study, combustion of pure methane and blended methane-hydrogen with hydrogen-levels up to 80% by volume has been conducted in a swirl stabilized premixed combustor. Particle imaging velocimetry (PIV) and OH* chemiluminescence imaging have been used in this study. Results show that there is a single-ringed structure of internal recirculation zone (IRZ) in the non-reacting flow, while in the reacting flows, there is a more complex flow pattern with a two-celled IRZ structure in which the axial velocity near the center-axis is oriented downstream. As the equivalence ratio decreases, the width of IRZ decreases in methane flames while it increases in hydrogen-enriched flames, and the flame shape changes from conical to an elongated columnar shape, especially in hydrogen-enriched flames. There are two different modes of vortex breakdown observed, spiral mode in methane flames and bubble mode in hydrogen-enriched flames. These differences between the behavior of the methane-only and hydrogen-enriched flames lead to different behavior of the flame as it approaches the lean blowout. The differences in the mechanisms of LBO in pure methane and hydrogen-enriched premixed flames are examined and explained in the present study. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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Application of an optimal tuner selection approach for on-board self-tuning engine models / Donald L. Simon in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 11 p. Titre : Application of an optimal tuner selection approach for on-board self-tuning engine models Type de document : texte imprimé Auteurs : Donald L. Simon, Auteur ; Jeffrey B. Armstrong, Auteur ; Sanjay Garg, Auteur Année de publication : 2012 Article en page(s) : 11 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Aerospace engines Aircraft control Closed loop systems Dynamic response Kalman filters Mean square error methods Open Optimisation Self-adjusting State estimation Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An enhanced design methodology for minimizing the error in on-line Kalman filter-based aircraft engine performance estimation applications is presented in this paper. It specifically addresses the under-determined estimation problem, in which there are more unknown parameters than available sensor measurements. This work builds upon an existing technique for systematically selecting a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. While the existing technique was optimized for open-loop engine operation at a fixed design point, in this paper an alternative formulation is presented that enables the technique to be optimized for an engine operating under closed-loop control throughout the flight envelope. The theoretical Kalman filter mean squared estimation error at a steady-state closed-loop operating point is derived, and the tuner selection approach applied to minimize this error is discussed. A technique for constructing a globally optimal tuning parameter vector, which enables full-envelope application of the technology, is also presented, along with design steps for adjusting the dynamic response of the Kalman filter state estimates. Results from the application of the technique to linear and nonlinear aircraft engine simulations are presented and compared to the conventional approach of tuner selection. The new methodology is shown to yield a significant improvement in on-line Kalman filter estimation accuracy. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Application of an optimal tuner selection approach for on-board self-tuning engine models [texte imprimé] / Donald L. Simon, Auteur ; Jeffrey B. Armstrong, Auteur ; Sanjay Garg, Auteur . - 2012 . - 11 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 11 p. Mots-clés : Aerospace engines Aircraft control Closed loop systems Dynamic response Kalman filters Mean square error methods Open Optimisation Self-adjusting State estimation Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An enhanced design methodology for minimizing the error in on-line Kalman filter-based aircraft engine performance estimation applications is presented in this paper. It specifically addresses the under-determined estimation problem, in which there are more unknown parameters than available sensor measurements. This work builds upon an existing technique for systematically selecting a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. While the existing technique was optimized for open-loop engine operation at a fixed design point, in this paper an alternative formulation is presented that enables the technique to be optimized for an engine operating under closed-loop control throughout the flight envelope. The theoretical Kalman filter mean squared estimation error at a steady-state closed-loop operating point is derived, and the tuner selection approach applied to minimize this error is discussed. A technique for constructing a globally optimal tuning parameter vector, which enables full-envelope application of the technology, is also presented, along with design steps for adjusting the dynamic response of the Kalman filter state estimates. Results from the application of the technique to linear and nonlinear aircraft engine simulations are presented and compared to the conventional approach of tuner selection. The new methodology is shown to yield a significant improvement in on-line Kalman filter estimation accuracy. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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aucun exemplaire

Selection of climatic design points for gas turbine power augmentation / Mustapha Chaker in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 14 p. Titre : Selection of climatic design points for gas turbine power augmentation Type de document : texte imprimé Auteurs : Mustapha Chaker, Auteur ; Cyrus B. Meher-Homji, Auteur Année de publication : 2012 Article en page(s) : 14 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Gas turbines Power transmission (mechanical) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : There is a widespread interest in the application of gas turbine power augmentation technologies such as evaporative cooling and mechanical chilling in the mechanical drive and power generation markets. Very often, the selection of the design point is based on the use of American Society of Heating and Refrigeration Engineers (ASHRAE) data or a design point that is in the basis of design for the project. This approach can be detrimental and can result in a non optimal solution. In order to evaluate the benefits of power augmentation, users can use locally collected weather data, or recorded hourly bin data set from databases such as typical meteorological year (TMY), engineering weather data (EWD), and integrated weather surface (IWS). This paper will cover a suggested approach for the analysis of climatic data for power augmentation applications and show how the selection of the design point can impact performance. The final selection of the design point depends on the specific application, the revenues generated and installation costs. To the authors' knowledge, this is the first attempt to treat this topic in a structured analytical manner by comparing available database information with actual climatic conditions. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Selection of climatic design points for gas turbine power augmentation [texte imprimé] / Mustapha Chaker, Auteur ; Cyrus B. Meher-Homji, Auteur . - 2012 . - 14 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 14 p. Mots-clés : Gas turbines Power transmission (mechanical) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : There is a widespread interest in the application of gas turbine power augmentation technologies such as evaporative cooling and mechanical chilling in the mechanical drive and power generation markets. Very often, the selection of the design point is based on the use of American Society of Heating and Refrigeration Engineers (ASHRAE) data or a design point that is in the basis of design for the project. This approach can be detrimental and can result in a non optimal solution. In order to evaluate the benefits of power augmentation, users can use locally collected weather data, or recorded hourly bin data set from databases such as typical meteorological year (TMY), engineering weather data (EWD), and integrated weather surface (IWS). This paper will cover a suggested approach for the analysis of climatic data for power augmentation applications and show how the selection of the design point can impact performance. The final selection of the design point depends on the specific application, the revenues generated and installation costs. To the authors' knowledge, this is the first attempt to treat this topic in a structured analytical manner by comparing available database information with actual climatic conditions. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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aucun exemplaire

Wind turbine gearbox fault detection using multiple sensors with features level data fusion / Y. Lu in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 08 p. Titre : Wind turbine gearbox fault detection using multiple sensors with features level data fusion Type de document : texte imprimé Auteurs : Y. Lu, Auteur ; Tang, J., Auteur ; H. Luo, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Accelerometers Acoustic emission Condition monitoring Fault diagnosis Feature extraction Gears Microphones Principal component analysis Sensor fusion Tachometers Time-frequency Vibrations Wind turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Fault detection in complex mechanical systems such as wind turbine gearboxes remains challenging, even with the recently significant advancement of sensing and signal processing technologies. As first-principle models of gearboxes capable of reflecting response details for health monitoring purpose are difficult to obtain, data-driven approaches are often adopted for fault detection, identification or classification. In this paper, we propose a data-driven framework that combines information from multiple sensors and fundamental physics of the gearbox. Time domain vibration and acoustic emission signals are collected from a gearbox dynamics testbed, where both healthy and faulty gears with different fault conditions are tested. To deal with the nonstationary nature of the wind turbine operation, a harmonic wavelet based method is utilized to extract the time-frequency features in the signals. This new framework features the employment of the tachometer readings and gear meshing relationships to develop a speed profile masking technique. The time-frequency wavelet features are highlighted by applying the mask we construct. Those highlighted features from multiple accelerometers and microphones are then fused together through a statistical weighting approach based on principal component analysis. Using the highlighted and fused features, we demonstrate that different gear faults can be effectively detected and identified. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Wind turbine gearbox fault detection using multiple sensors with features level data fusion [texte imprimé] / Y. Lu, Auteur ; Tang, J., Auteur ; H. Luo, Auteur . - 2012 . - 08 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 08 p. Mots-clés : Accelerometers Acoustic emission Condition monitoring Fault diagnosis Feature extraction Gears Microphones Principal component analysis Sensor fusion Tachometers Time-frequency Vibrations Wind turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Fault detection in complex mechanical systems such as wind turbine gearboxes remains challenging, even with the recently significant advancement of sensing and signal processing technologies. As first-principle models of gearboxes capable of reflecting response details for health monitoring purpose are difficult to obtain, data-driven approaches are often adopted for fault detection, identification or classification. In this paper, we propose a data-driven framework that combines information from multiple sensors and fundamental physics of the gearbox. Time domain vibration and acoustic emission signals are collected from a gearbox dynamics testbed, where both healthy and faulty gears with different fault conditions are tested. To deal with the nonstationary nature of the wind turbine operation, a harmonic wavelet based method is utilized to extract the time-frequency features in the signals. This new framework features the employment of the tachometer readings and gear meshing relationships to develop a speed profile masking technique. The time-frequency wavelet features are highlighted by applying the mask we construct. Those highlighted features from multiple accelerometers and microphones are then fused together through a statistical weighting approach based on principal component analysis. Using the highlighted and fused features, we demonstrate that different gear faults can be effectively detected and identified. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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aucun exemplaire

The deduction of the integral and the estimation of the local core rotation ratio by telemetric pressure measurements in a two cavity test rig / Wieland Uffrecht in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 12 p. Titre : The deduction of the integral and the estimation of the local core rotation ratio by telemetric pressure measurements in a two cavity test rig Type de document : texte imprimé Auteurs : Wieland Uffrecht, Auteur ; André Günther, Auteur Année de publication : 2012 Article en page(s) : 12 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Confined flow Flow measurement Gas turbines Heat transfer Pressure Rotational Telemetry Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The heat transfer in rotating cavities, as found in the internal air system of gas turbines, is mainly governed by the flow passing through these specific machine structures. The core rotation ratio represents the circumferential velocity, and is thought to be an influential flow parameter for heat transfer in rotating cavities with radial flow-through. Therefore, this paper focuses on deducing the core rotation ratio and the estimation of its local distribution using telemetric pressure measurements. The local core rotation ratio depends on the radial pressure distribution in a rotating cavity system. Thus, an integral core rotation ratio can be determined from pressure measurements in the rotating cavity system. A flow structure-based approximation of the measurements allows an estimation of the radial distribution of the core rotation ratio in the rotating cavity. The results of the measurements with varied flow rates and revolving speeds are presented, as well as a discussion of the fit parameters and their dependency on the operation mode of the test rig. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] The deduction of the integral and the estimation of the local core rotation ratio by telemetric pressure measurements in a two cavity test rig [texte imprimé] / Wieland Uffrecht, Auteur ; André Günther, Auteur . - 2012 . - 12 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 12 p. Mots-clés : Confined flow Flow measurement Gas turbines Heat transfer Pressure Rotational Telemetry Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The heat transfer in rotating cavities, as found in the internal air system of gas turbines, is mainly governed by the flow passing through these specific machine structures. The core rotation ratio represents the circumferential velocity, and is thought to be an influential flow parameter for heat transfer in rotating cavities with radial flow-through. Therefore, this paper focuses on deducing the core rotation ratio and the estimation of its local distribution using telemetric pressure measurements. The local core rotation ratio depends on the radial pressure distribution in a rotating cavity system. Thus, an integral core rotation ratio can be determined from pressure measurements in the rotating cavity system. A flow structure-based approximation of the measurements allows an estimation of the radial distribution of the core rotation ratio in the rotating cavity. The results of the measurements with varied flow rates and revolving speeds are presented, as well as a discussion of the fit parameters and their dependency on the operation mode of the test rig. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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aucun exemplaire

Rotordynamic force coefficients for three types of annular gas seals with inlet preswirl and high differential pressure ratio / B. H. Ertas in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 12 p. Titre : Rotordynamic force coefficients for three types of annular gas seals with inlet preswirl and high differential pressure ratio Type de document : texte imprimé Auteurs : B. H. Ertas, Auteur ; A. Delgado, Auteur ; G. Vannini, Auteur Année de publication : 2012 Article en page(s) : 12 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Compressors Mechanical testing Rotors Seals (stoppers) Shock absorbers Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The following paper presents and compares rotordynamic force coefficients for three types of non-contact annular gas seals, which include a labyrinth (LABY), honeycomb (HC), and a fully partitioned damper seal (FPDS). These three annular seals represent the typical seal types used in process gas centrifugal compressors at the balance piston location or center seal location to limit internal leakage and ensure a robust rotordynamic design. Tests were conducted on 170.6 mm (6.716 in) diameter seals for rotor speeds up to 15 kprm, inlet air pressure of 6.9 bar (100 psi), ambient back pressure, and with inlet gas preswirl. The three seals were designed to have the same nominal clearance and similar axial lengths. Testing was conducted on a controlled motion test rig possessing non-synchronous excitation capability up to 250 Hz. Three different test methods were employed to give confidence in the rotordynamic coefficients, which include static force deflection tests, mechanical impedance tests, and dynamic cavity pressure tests. Results from experiments compare force coefficients for all seal configurations while paying special attention to the crossover frequencies of the effective damping term. All seals possessed negative effective damping at lower excitation frequencies with inlet preswirl, where the straight-through FPDS possessed the lowest cross over frequency of 40 Hz at 15 krpm. The testing also revealed that the preswirl parameter had significantly more influence on effective damping levels and crossover frequencies when compared to rotor speed. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Rotordynamic force coefficients for three types of annular gas seals with inlet preswirl and high differential pressure ratio [texte imprimé] / B. H. Ertas, Auteur ; A. Delgado, Auteur ; G. Vannini, Auteur . - 2012 . - 12 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 12 p. Mots-clés : Compressors Mechanical testing Rotors Seals (stoppers) Shock absorbers Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The following paper presents and compares rotordynamic force coefficients for three types of non-contact annular gas seals, which include a labyrinth (LABY), honeycomb (HC), and a fully partitioned damper seal (FPDS). These three annular seals represent the typical seal types used in process gas centrifugal compressors at the balance piston location or center seal location to limit internal leakage and ensure a robust rotordynamic design. Tests were conducted on 170.6 mm (6.716 in) diameter seals for rotor speeds up to 15 kprm, inlet air pressure of 6.9 bar (100 psi), ambient back pressure, and with inlet gas preswirl. The three seals were designed to have the same nominal clearance and similar axial lengths. Testing was conducted on a controlled motion test rig possessing non-synchronous excitation capability up to 250 Hz. Three different test methods were employed to give confidence in the rotordynamic coefficients, which include static force deflection tests, mechanical impedance tests, and dynamic cavity pressure tests. Results from experiments compare force coefficients for all seal configurations while paying special attention to the crossover frequencies of the effective damping term. All seals possessed negative effective damping at lower excitation frequencies with inlet preswirl, where the straight-through FPDS possessed the lowest cross over frequency of 40 Hz at 15 krpm. The testing also revealed that the preswirl parameter had significantly more influence on effective damping levels and crossover frequencies when compared to rotor speed. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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aucun exemplaire

Eddy current damper for turbine blading / Jacob Laborenz in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 08 p. Titre : Eddy current damper for turbine blading : electromagnetic finite element analysis and measurement results Type de document : texte imprimé Auteurs : Jacob Laborenz, Auteur ; Malte Krack, Auteur ; Lars Panning, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Blades Damping Eddy currents Finite element analysis Turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In the dynamics of turbomachinery, the mechanical damping of the blading has been the focus of research for the last decades to improve the dynamic performance in terms of high cycle fatigue issues. In addition, an increased mechanical damping can produce a higher flutter safety margin such that stable operation conditions are achievable in a bigger range. Hence, novel damping techniques are considered besides the well known friction based damping devices. In this paper, an extended analysis of the eddy current based damping device for a last stage steam turbine blading presented in GT2009-59593 is conducted. A transient electromagnetic finite element analysis of the eddy current damper is performed, and the resulting damping forces are compared to their analytical solution. Parameter studies are carried out, and equivalent damping factors are calculated. Furthermore, for the validation of the finite element model, a test rig was built that allows for the direct measurement of damping forces when forcing a sinusoidal relative motion. Forced response measurements and simulations are used to demonstrate its dynamic performance and predictability. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Eddy current damper for turbine blading : electromagnetic finite element analysis and measurement results [texte imprimé] / Jacob Laborenz, Auteur ; Malte Krack, Auteur ; Lars Panning, Auteur . - 2012 . - 08 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 08 p. Mots-clés : Blades Damping Eddy currents Finite element analysis Turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In the dynamics of turbomachinery, the mechanical damping of the blading has been the focus of research for the last decades to improve the dynamic performance in terms of high cycle fatigue issues. In addition, an increased mechanical damping can produce a higher flutter safety margin such that stable operation conditions are achievable in a bigger range. Hence, novel damping techniques are considered besides the well known friction based damping devices. In this paper, an extended analysis of the eddy current based damping device for a last stage steam turbine blading presented in GT2009-59593 is conducted. A transient electromagnetic finite element analysis of the eddy current damper is performed, and the resulting damping forces are compared to their analytical solution. Parameter studies are carried out, and equivalent damping factors are calculated. Furthermore, for the validation of the finite element model, a test rig was built that allows for the direct measurement of damping forces when forcing a sinusoidal relative motion. Forced response measurements and simulations are used to demonstrate its dynamic performance and predictability. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Predicting blade leading edge erosion in an axial induced draft fan / Alessandro Corsini in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 09 p. Titre : Predicting blade leading edge erosion in an axial induced draft fan Type de document : texte imprimé Auteurs : Alessandro Corsini, Auteur ; Andrea Marchegiani, Auteur ; Franco Rispoli, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Blades Boilers Combustion Computational fluid dynamics Erosion Finite element analysis Turbomachinery Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Induced draft fans extract coal fired boiler combustion products, including particles of un-burnt coal and ash. As a consequence of the particles, the axial fan blades' leading edges are subject to erosion. Erosion results in the loss of the blade leading edge aerodynamic profile and a reduction of blade chord and effective camber that together degrade aerodynamic performance. An experimental study demonstrated that while the degradation of aerodynamic performance begins gradually, it collapses as blade erosion reaches a critical limit. This paper presents a numerical study on the evolution of blade leading edge erosion patterns in an axial induced draft fan. The authors calculated particle trajectories using an in-house computational fluid dynamic (CFD) solver coupled with a trajectory predicting solver based on an original finite element interpolation scheme. The numerical study clarifies the influence of flow structure, initial blade geometry, particle size, and concentration on erosion pattern. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Predicting blade leading edge erosion in an axial induced draft fan [texte imprimé] / Alessandro Corsini, Auteur ; Andrea Marchegiani, Auteur ; Franco Rispoli, Auteur . - 2012 . - 09 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 09 p. Mots-clés : Blades Boilers Combustion Computational fluid dynamics Erosion Finite element analysis Turbomachinery Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Induced draft fans extract coal fired boiler combustion products, including particles of un-burnt coal and ash. As a consequence of the particles, the axial fan blades' leading edges are subject to erosion. Erosion results in the loss of the blade leading edge aerodynamic profile and a reduction of blade chord and effective camber that together degrade aerodynamic performance. An experimental study demonstrated that while the degradation of aerodynamic performance begins gradually, it collapses as blade erosion reaches a critical limit. This paper presents a numerical study on the evolution of blade leading edge erosion patterns in an axial induced draft fan. The authors calculated particle trajectories using an in-house computational fluid dynamic (CFD) solver coupled with a trajectory predicting solver based on an original finite element interpolation scheme. The numerical study clarifies the influence of flow structure, initial blade geometry, particle size, and concentration on erosion pattern. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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Stall inception, evolution and control in a low speed axial fan with variable pitch in motion / Stefano Bianchi in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 10 p. Titre : Stall inception, evolution and control in a low speed axial fan with variable pitch in motion Type de document : texte imprimé Auteurs : Stefano Bianchi, Auteur ; Alessandro Corsini, Auteur ; Luca Mazzucco, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Blades Fans Flow instability Probes Rotors Turbomachinery Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Obtaining the right pitch in turbomachinery blading is crucial to efficient and successful operations. Engineers adjust the rotor's pitch angle to control the production or absorption of power. Even for low speed fans this is a promising tool. This paper focuses on the inception and the evolution of the flow instabilities in the tip region which drive the stall onset in low speed axial fans. The authors conducted an experimental study to investigate the inception patterns of rotating stall evolution at different rotor blade stagger-angle settings with the aim of speculating on stable operating margin. The authors drove the fan to stall at the design stagger-angle setting and then operated the variable pitch mechanism in order to recover the unstable operation. They measured pressure fluctuations in the tip region of the low-speed axial-flow fan fitted with a variable pitch in motion mechanism, with flush mounted probes. The authors studied the flow mechanisms for spike and modal stall inceptions in this low-speed axial-flow fan which showed relatively small tip clearance. The authors cross-correlated the pressure fluctuations and analyzed the cross-spectra in order to clarify blade pitch, end wall flow, and tip-leakage flow influences on stall inception during the transient at the rotor blades' different stagger-angle settings. The authors observed a rotating instability near the maximum pressure-rise point at both design and low stagger-angle settings. The stall inception patterns were a spike type at the design stagger-angle setting as a result of the interaction between the incoming flow, tip-leakage flow and end wall backflow. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Stall inception, evolution and control in a low speed axial fan with variable pitch in motion [texte imprimé] / Stefano Bianchi, Auteur ; Alessandro Corsini, Auteur ; Luca Mazzucco, 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° 4 (Avril 2012) . - 10 p. Mots-clés : Blades Fans Flow instability Probes Rotors Turbomachinery Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Obtaining the right pitch in turbomachinery blading is crucial to efficient and successful operations. Engineers adjust the rotor's pitch angle to control the production or absorption of power. Even for low speed fans this is a promising tool. This paper focuses on the inception and the evolution of the flow instabilities in the tip region which drive the stall onset in low speed axial fans. The authors conducted an experimental study to investigate the inception patterns of rotating stall evolution at different rotor blade stagger-angle settings with the aim of speculating on stable operating margin. The authors drove the fan to stall at the design stagger-angle setting and then operated the variable pitch mechanism in order to recover the unstable operation. They measured pressure fluctuations in the tip region of the low-speed axial-flow fan fitted with a variable pitch in motion mechanism, with flush mounted probes. The authors studied the flow mechanisms for spike and modal stall inceptions in this low-speed axial-flow fan which showed relatively small tip clearance. The authors cross-correlated the pressure fluctuations and analyzed the cross-spectra in order to clarify blade pitch, end wall flow, and tip-leakage flow influences on stall inception during the transient at the rotor blades' different stagger-angle settings. The authors observed a rotating instability near the maximum pressure-rise point at both design and low stagger-angle settings. The stall inception patterns were a spike type at the design stagger-angle setting as a result of the interaction between the incoming flow, tip-leakage flow and end wall backflow. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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aucun exemplaire

Effects of wind turbine starting capability on energy yield / Supakit Worasinchai in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 09 p. Titre : Effects of wind turbine starting capability on energy yield Type de document : texte imprimé Auteurs : Supakit Worasinchai, Auteur ; Grant L. Ingram, Auteur ; Robert G. Dominy, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Aerodynamics Battery chargers Blades Power grids Wind turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The purpose of this study was to investigate the effect of turbine starting capability on overall energy-production capacity. The investigation was performed through the development and validation of matlab/Simulink models of turbines. A novel aspect of this paper is that the effects of load types, namely resistive heating, battery charging, and grid connection were also investigated. It was shown that major contributors to improved starting performance are aerodynamic improvements, reduction of inertia, and simply changing the pitch angle of the blades. The first two contributors can be attained from an exploitation of a “mixed-airfoil” blade.The results indicate that starting ability has a direct effect on the duration that the turbine can operate and consequently its overall energy output. The overall behavior of the wind turbine system depends on the load type, these impose different torque characteristics for the turbine to overcome and lead to different power production characteristics.When a “mixed-airfoil” blade is used the annual energy production of the wind systems increases with the exception of resistive heating loads. Net changes in annual energy production were range of −4% to 40% depending on the load types and sites considered. The significant improvement in energy production strongly suggests that both the starting performance and load types should be considered together in the design process. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Effects of wind turbine starting capability on energy yield [texte imprimé] / Supakit Worasinchai, Auteur ; Grant L. Ingram, Auteur ; Robert G. Dominy, Auteur . - 2012 . - 09 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 09 p. Mots-clés : Aerodynamics Battery chargers Blades Power grids Wind turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The purpose of this study was to investigate the effect of turbine starting capability on overall energy-production capacity. The investigation was performed through the development and validation of matlab/Simulink models of turbines. A novel aspect of this paper is that the effects of load types, namely resistive heating, battery charging, and grid connection were also investigated. It was shown that major contributors to improved starting performance are aerodynamic improvements, reduction of inertia, and simply changing the pitch angle of the blades. The first two contributors can be attained from an exploitation of a “mixed-airfoil” blade.The results indicate that starting ability has a direct effect on the duration that the turbine can operate and consequently its overall energy output. The overall behavior of the wind turbine system depends on the load type, these impose different torque characteristics for the turbine to overcome and lead to different power production characteristics.When a “mixed-airfoil” blade is used the annual energy production of the wind systems increases with the exception of resistive heating loads. Net changes in annual energy production were range of −4% to 40% depending on the load types and sites considered. The significant improvement in energy production strongly suggests that both the starting performance and load types should be considered together in the design process. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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aucun exemplaire

Ion current, combustion and emission characteristics in an automotive common rail diesel engine / Naeim A. Henein in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 07 p. Titre : Ion current, combustion and emission characteristics in an automotive common rail diesel engine Type de document : texte imprimé Auteurs : Naeim A. Henein, Auteur ; Tamer Badawy, Auteur ; Nilesh Rai, Auteur ; Walter Bryzik, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Combustion Diesel engines Rails Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Advanced electronically controlled diesel engines require a feedback signal to the ECU to adjust different operating parameters and meet demands for power, better fuel economy and low emissions. Different types of in-cylinder combustion sensors are being considered to produce this signal. This paper presents results of an experimental investigation on the characteristics of the ion current in an automotive diesel engine equipped with a common rail injection system. The engine is a 1.9 L, 4-cylinder, direct injection diesel engine. Experiments covered different engine loads and injection pressures. The relationships between the ion current, combustion parameters and engine out NO emissions and opacity are presented. The analysis of the experimental data identified possible sources of the ion current produced in diesel engines. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Ion current, combustion and emission characteristics in an automotive common rail diesel engine [texte imprimé] / Naeim A. Henein, Auteur ; Tamer Badawy, Auteur ; Nilesh Rai, Auteur ; Walter Bryzik, Auteur . - 2012 . - 07 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 07 p. Mots-clés : Combustion Diesel engines Rails Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Advanced electronically controlled diesel engines require a feedback signal to the ECU to adjust different operating parameters and meet demands for power, better fuel economy and low emissions. Different types of in-cylinder combustion sensors are being considered to produce this signal. This paper presents results of an experimental investigation on the characteristics of the ion current in an automotive diesel engine equipped with a common rail injection system. The engine is a 1.9 L, 4-cylinder, direct injection diesel engine. Experiments covered different engine loads and injection pressures. The relationships between the ion current, combustion parameters and engine out NO emissions and opacity are presented. The analysis of the experimental data identified possible sources of the ion current produced in diesel engines. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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Air system and diesel combustion modeling for hardware in the loop applications / Jean-Baptiste Millet in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 12 p. Titre : Air system and diesel combustion modeling for hardware in the loop applications Type de document : texte imprimé Auteurs : Jean-Baptiste Millet, Auteur ; Maroteaux, Fadila, Auteur ; Fabrice Aubertin, Auteur Année de publication : 2012 Article en page(s) : 12 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Air cleaners Automobile manufacture Automotive components electronics Catalysts Combustion Computerised instrumentation Diesel engines Exhaust systems Mechanical engineering computing Vehicle dynamics Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The development of engine control unit (ECU) systems for series production requires an important validation phase. In order to reduce the number of time consuming and expensive vehicle tests, the ECU is validated using hardware in the loop (HIL) test bench. The HIL simulates the engine behavior in real-time simulations to generate consistent sensor values for all engine operating points, e.g., starting phase, transient behavior, static behavior, etc. Mean value engine models (MVEM) are able to run in real time and are appropriate for HIL test systems. In this paper we present a full MVEM taking into account all engine components: air system (air filter, turbocharger, charge air cooler, throttle valve, intake and exhaust manifolds, EGR valve, and turbine), oxidation catalyst (OxiCat), and diesel particulate filter (DPF). Additionally, combustion models have been developed to simulate the influence of the injection strategies (pre, main, post, and late injections) on the exhaust temperature and the unburned hydrocarbon emission (HC). These are taken into consideration in the exothermal reactions models inside OxiCat and DPF. The results show that the model prediction in term of pressure and temperature are in good agreement with the original equipment manufacturer (OEM) project data. The after treatment temperature evolutions in the OxiCat and DPF are well reproduced by the proposed model. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Air system and diesel combustion modeling for hardware in the loop applications [texte imprimé] / Jean-Baptiste Millet, Auteur ; Maroteaux, Fadila, Auteur ; Fabrice Aubertin, Auteur . - 2012 . - 12 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 12 p. Mots-clés : Air cleaners Automobile manufacture Automotive components electronics Catalysts Combustion Computerised instrumentation Diesel engines Exhaust systems Mechanical engineering computing Vehicle dynamics Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The development of engine control unit (ECU) systems for series production requires an important validation phase. In order to reduce the number of time consuming and expensive vehicle tests, the ECU is validated using hardware in the loop (HIL) test bench. The HIL simulates the engine behavior in real-time simulations to generate consistent sensor values for all engine operating points, e.g., starting phase, transient behavior, static behavior, etc. Mean value engine models (MVEM) are able to run in real time and are appropriate for HIL test systems. In this paper we present a full MVEM taking into account all engine components: air system (air filter, turbocharger, charge air cooler, throttle valve, intake and exhaust manifolds, EGR valve, and turbine), oxidation catalyst (OxiCat), and diesel particulate filter (DPF). Additionally, combustion models have been developed to simulate the influence of the injection strategies (pre, main, post, and late injections) on the exhaust temperature and the unburned hydrocarbon emission (HC). These are taken into consideration in the exothermal reactions models inside OxiCat and DPF. The results show that the model prediction in term of pressure and temperature are in good agreement with the original equipment manufacturer (OEM) project data. The after treatment temperature evolutions in the OxiCat and DPF are well reproduced by the proposed model. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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Telemetry system integrated in a small gas turbine engine / Stephen A. Long in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 05 p. Titre : Telemetry system integrated in a small gas turbine engine Type de document : texte imprimé Auteurs : Stephen A. Long, Auteur ; Stephen L Edney, Auteur ; Patrick A Reiger, Auteur Année de publication : 2012 Article en page(s) : 05 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Combustion Cooling Engines Finite element analysis Gas turbines Modules Strain gauges Telemetry Test equipment Thermal Thermocouples Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : For the purpose of assessing combustion effects in a small gas turbine engine, there was a requirement to evaluate the rotating temperature and dynamic characteristics of the power turbine rotor module. This assessment required measurements be taken within the engine, during operation up to maximum power, using rotor mounted thermocouples and strain gauges. The acquisition of this data necessitated the use of a telemetry system that could be integrated into the existing engine architecture without affecting performance. As a result of space constraints, housing of the telemetry module was limited to placement in a hot section. To tolerate the high temperature environment, a cooling system was developed as part of the integration effort to maintain telemetry module temperatures within the limit allowed by the electronics. Finite element thermal analysis was used to guide the design of the cooling system. This was to ensure that sufficient airflow was introduced and appropriately distributed to cool the telemetry cavity, and hence electronics, without affecting the performance of the engine. Presented herein is a discussion of the telemetry system, instrumentation design philosophy, cooling system design and verification, and sample of the results acquired through successful execution of the full engine test program. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Telemetry system integrated in a small gas turbine engine [texte imprimé] / Stephen A. Long, Auteur ; Stephen L Edney, Auteur ; Patrick A Reiger, Auteur . - 2012 . - 05 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 05 p. Mots-clés : Combustion Cooling Engines Finite element analysis Gas turbines Modules Strain gauges Telemetry Test equipment Thermal Thermocouples Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : For the purpose of assessing combustion effects in a small gas turbine engine, there was a requirement to evaluate the rotating temperature and dynamic characteristics of the power turbine rotor module. This assessment required measurements be taken within the engine, during operation up to maximum power, using rotor mounted thermocouples and strain gauges. The acquisition of this data necessitated the use of a telemetry system that could be integrated into the existing engine architecture without affecting performance. As a result of space constraints, housing of the telemetry module was limited to placement in a hot section. To tolerate the high temperature environment, a cooling system was developed as part of the integration effort to maintain telemetry module temperatures within the limit allowed by the electronics. Finite element thermal analysis was used to guide the design of the cooling system. This was to ensure that sufficient airflow was introduced and appropriately distributed to cool the telemetry cavity, and hence electronics, without affecting the performance of the engine. Presented herein is a discussion of the telemetry system, instrumentation design philosophy, cooling system design and verification, and sample of the results acquired through successful execution of the full engine test program. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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Numerical investigation of a centrifugal compressor with holed casing treatment / Wei Xu in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 04 p. Titre : Numerical investigation of a centrifugal compressor with holed casing treatment Type de document : texte imprimé Auteurs : Wei Xu, Auteur ; Tong Wang, Auteur ; Chuangang Gu, Auteur ; Liang Ding, Auteur Année de publication : 2012 Article en page(s) : 04 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Compressors Flow instability simulation Impellers Numerical analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The holed casing treatment is a new type of casing treatment that has self-adaptability for a centrifugal compressor with unshrouded impeller. It was demonstrated experimentally and numerically that both the stall margin and the choked margin of the compressor were able to be expanded by the treatment. Numerical results indicate that there is reinjected flow in the holes when the compressor works at low flow rate conditions, and bypass flow at high flow rate conditions. The key principles for choosing the diameter and the radial position of the hole are presented in this paper. The hole's diameter is an important parameter for the holed casing treatment. Five numerical cases with different diameters (1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm and 3.0 mm) were carried out to compare the results. The reinjected flow enters into the impeller passage periodically and it tends to increase when the hole diameter gets larger. In the case of 2.5 mm, both the stall margin increment and the efficiency of the compressor were the highest among the five cases. Unsteady simulations suggest that the reinjected flow is not only periodic in time but also periodic in circumferential direction. This is the reason why only 2% of the flow amounts would get 20% of the working range expansion. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Numerical investigation of a centrifugal compressor with holed casing treatment [texte imprimé] / Wei Xu, Auteur ; Tong Wang, Auteur ; Chuangang Gu, Auteur ; Liang Ding, Auteur . - 2012 . - 04 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 04 p. Mots-clés : Compressors Flow instability simulation Impellers Numerical analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The holed casing treatment is a new type of casing treatment that has self-adaptability for a centrifugal compressor with unshrouded impeller. It was demonstrated experimentally and numerically that both the stall margin and the choked margin of the compressor were able to be expanded by the treatment. Numerical results indicate that there is reinjected flow in the holes when the compressor works at low flow rate conditions, and bypass flow at high flow rate conditions. The key principles for choosing the diameter and the radial position of the hole are presented in this paper. The hole's diameter is an important parameter for the holed casing treatment. Five numerical cases with different diameters (1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm and 3.0 mm) were carried out to compare the results. The reinjected flow enters into the impeller passage periodically and it tends to increase when the hole diameter gets larger. In the case of 2.5 mm, both the stall margin increment and the efficiency of the compressor were the highest among the five cases. Unsteady simulations suggest that the reinjected flow is not only periodic in time but also periodic in circumferential direction. This is the reason why only 2% of the flow amounts would get 20% of the working range expansion. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

Exemplaires

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Performance of a direct injection diesel engine fueled by a heavy oil with the addition of low density polyethylene (LDPE) polymer / V. Soloiu in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 04 p. Titre : Performance of a direct injection diesel engine fueled by a heavy oil with the addition of low density polyethylene (LDPE) polymer Type de document : texte imprimé Auteurs : V. Soloiu, Auteur ; A. Covington, Auteur Année de publication : 2012 Article en page(s) : 04 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Combustion Diesel engines Plastics Polymers Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Considering the escalating cost of fossil fuels in correlation with the growing influence of sustainability, the need to seek new alternative fuels is increasing rapidly. This movement has lead researchers to look beyond the usual alternative fuels and focus on plastics as an energy resource in the form of a low density polyethylene (LDPE) used throughout the global community. The authors investigated the injection and combustion of a new class of polymer fuel containing 5% LDPE by weight in a heavy fuel oil (AHFO) in a direct injection diesel engine, in order to evaluate its effectiveness for application as a new alternative fuel. The analysis occurred at 1200 rpm, under loads that ranged from BMEP 1.4-6.04 bar. In order to maintain the fuel's viscosity around 20 cSt the fuel was heated at 130-150 °C. The smoke (bosch) and emission analysis were also performed and provided promising results in terms of engine performance. This suggests that the feedstock of LDPE may be a viable substitute for AHFO for application in a diesel engine with the addressing of the technical challenges associated with the injection system operation. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Performance of a direct injection diesel engine fueled by a heavy oil with the addition of low density polyethylene (LDPE) polymer [texte imprimé] / V. Soloiu, Auteur ; A. Covington, Auteur . - 2012 . - 04 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 04 p. Mots-clés : Combustion Diesel engines Plastics Polymers Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Considering the escalating cost of fossil fuels in correlation with the growing influence of sustainability, the need to seek new alternative fuels is increasing rapidly. This movement has lead researchers to look beyond the usual alternative fuels and focus on plastics as an energy resource in the form of a low density polyethylene (LDPE) used throughout the global community. The authors investigated the injection and combustion of a new class of polymer fuel containing 5% LDPE by weight in a heavy fuel oil (AHFO) in a direct injection diesel engine, in order to evaluate its effectiveness for application as a new alternative fuel. The analysis occurred at 1200 rpm, under loads that ranged from BMEP 1.4-6.04 bar. In order to maintain the fuel's viscosity around 20 cSt the fuel was heated at 130-150 °C. The smoke (bosch) and emission analysis were also performed and provided promising results in terms of engine performance. This suggests that the feedstock of LDPE may be a viable substitute for AHFO for application in a diesel engine with the addressing of the technical challenges associated with the injection system operation. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

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Two algorithms for the reliable estimation of organic rankine cycle performance / Guillaume Becquin in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 4 (Avril 2012)  

Public ISBD [article]  inTransactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 05 p. Titre : Two algorithms for the reliable estimation of organic rankine cycle performance Type de document : texte imprimé Auteurs : Guillaume Becquin, Auteur ; Matthew Lehar, Auteur Année de publication : 2012 Article en page(s) : 05 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Heat recovery Steam power stations Waste-to-energy plants Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : As the demand grows for low-temperature waste heat recovery systems, organic Rankine cycles (ORCs), and other alternatives to traditional steam, Rankine cycles are becoming more common in industry. Although analytical tools exist that can predict the performance of a steam cycle in a given waste-heat application, the development of a similar tool for ORCs has been hampered by the large choice of possible working fluids. In this paper, two methods are presented with the aim of providing an estimate of the best performance possible for any ORC in a given industrial application. The first is a purely analytical approach assuming an idealized fluid, and the second compares real fluids through cycle simulations to select the most appropriate parameters for the application. The analytical approach provides a rough baseline for performance, while the simulation method refines the estimate to give predictions that are more consistent with the documented performance of ORC plants currently in operation. Together, the two approaches represent a robust means of quickly estimating the capability of an ORC plant and to allow quick comparisons with other technologies. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...] [article] Two algorithms for the reliable estimation of organic rankine cycle performance [texte imprimé] / Guillaume Becquin, Auteur ; Matthew Lehar, Auteur . - 2012 . - 05 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 4 (Avril 2012) . - 05 p. Mots-clés : Heat recovery Steam power stations Waste-to-energy plants Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : As the demand grows for low-temperature waste heat recovery systems, organic Rankine cycles (ORCs), and other alternatives to traditional steam, Rankine cycles are becoming more common in industry. Although analytical tools exist that can predict the performance of a steam cycle in a given waste-heat application, the development of a similar tool for ORCs has been hampered by the large choice of possible working fluids. In this paper, two methods are presented with the aim of providing an estimate of the best performance possible for any ORC in a given industrial application. The first is a purely analytical approach assuming an idealized fluid, and the second compares real fluids through cycle simulations to select the most appropriate parameters for the application. The analytical approach provides a rough baseline for performance, while the simulation method refines the estimate to give predictions that are more consistent with the documented performance of ORC plants currently in operation. Together, the two approaches represent a robust means of quickly estimating the capability of an ORC plant and to allow quick comparisons with other technologies. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000004 [...]

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