Dépouillements

Gas turbines fired with biomass pyrolysis syngas / Simone Colantoni in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Titre : Gas turbines fired with biomass pyrolysis syngas : analysis of the overheating of hot gas path components Type de document : texte imprimé Auteurs : Simone Colantoni, Auteur ; Stefania Della Gatta, Auteur ; Roberto De Prosperis, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Bioenergy  conversion  Gas  turbines  Numerical  analysis  Pyrolysis  Thermal  analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Alternative resources, such as biomass, and municipal and industrial waste are being considered as a source for the production of syngas to replace natural gas as a power turbine fuel. Pyrolysis of biomass produces a syngas composed primarily of CO, CO2, CH4, and H2 with a medium-low lower heating value that is strongly dependent on the process boundary conditions such as the pyrolysis temperature and product residence time in the reactor. The issues associated with conventional gas turbines also apply to syngas turbines with the added complexity of the fuel and impurities. At present, syngas turbines are operated at firing temperatures similar to those of turbines fired on natural gas by increasing the fuel mass flow through the turbine. While this produces a higher turbine power output, the heat transferred to the hot flow-path vanes and blades is also greater. The aim of this paper is to report on the use of numerical modeling to analyze the fundamental impact of firing gas turbines with biomass pyrolysis syngas. To complete the analysis, the results have been compared with data from the literature on gas turbines fired with coal gasification syngas. The test engine used to perform this analysis is a General Electric GE10-2 gas turbine. The performance, aerodynamics and secondary flows were computed using proprietary software, while a commercial finite element software was used to perform the thermal and local creep analyses. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Gas turbines fired with biomass pyrolysis syngas : analysis of the overheating of hot gas path components [texte imprimé] / Simone Colantoni, Auteur ; Stefania Della Gatta, Auteur ; Roberto De Prosperis, Auteur . - 2011 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Mots-clés : Bioenergy  conversion  Gas  turbines  Numerical  analysis  Pyrolysis  Thermal  analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Alternative resources, such as biomass, and municipal and industrial waste are being considered as a source for the production of syngas to replace natural gas as a power turbine fuel. Pyrolysis of biomass produces a syngas composed primarily of CO, CO2, CH4, and H2 with a medium-low lower heating value that is strongly dependent on the process boundary conditions such as the pyrolysis temperature and product residence time in the reactor. The issues associated with conventional gas turbines also apply to syngas turbines with the added complexity of the fuel and impurities. At present, syngas turbines are operated at firing temperatures similar to those of turbines fired on natural gas by increasing the fuel mass flow through the turbine. While this produces a higher turbine power output, the heat transferred to the hot flow-path vanes and blades is also greater. The aim of this paper is to report on the use of numerical modeling to analyze the fundamental impact of firing gas turbines with biomass pyrolysis syngas. To complete the analysis, the results have been compared with data from the literature on gas turbines fired with coal gasification syngas. The test engine used to perform this analysis is a General Electric GE10-2 gas turbine. The performance, aerodynamics and secondary flows were computed using proprietary software, while a commercial finite element software was used to perform the thermal and local creep analyses. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Interaction between the acoustic pressure fluctuations and the unsteady flow field through circular holes / Jochen Rupp in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 09 p. Titre : Interaction between the acoustic pressure fluctuations and the unsteady flow field through circular holes Type de document : texte imprimé Auteurs : Jochen Rupp, Auteur ; Jon Carrotte, Auteur ; Adrian Spencer, Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Acoustic  intensity  measurement  Combustion  Damping  Ducts  Flow  Gas  turbines  Loudspeakers  Pressure  measurement Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Gas turbine combustion systems are prone to thermo-acoustic instabilities, and this is particularly the case for new low emission lean burn type systems. The presence of such instabilities is basically a function of the unsteady heat release within the system (i.e., both magnitude and phase) and the amount of damping. This paper is concerned with this latter process and the potential damping provided by perforated liners and other circular apertures found within gas turbine combustion systems. In particular, the paper outlines experimental measurements that characterize the flow field within the near field region of circular apertures when being subjected to incident acoustic pressure fluctuations. In this way the fundamental process by which acoustic energy is converted into kinetic energy of the velocity field can be investigated. Experimental results are presented for a single orifice located in an isothermal duct at ambient test conditions. Attached to the duct are two loudspeakers that provide pressure fluctuations incident onto the orifice. Unsteady pressure measurements enable the acoustic power absorbed by the orifice to be determined. This was undertaken for a range of excitation amplitudes and mean flows through the orifice. In this way regimes where both linear and nonlinear absorption occur along with the transition between these regimes can be investigated. The key to designing efficient passive dampers is to understand the interaction between the unsteady velocity field, generated at the orifice and the acoustic pressure fluctuations. Hence experimental techniques are also presented that enable such detailed measurements of the flow field to be made using particle image velocimetry. These measurements were obtained for conditions at which linear and nonlinear absorption was observed. Furthermore, proper orthogonal decomposition was used as a novel analysis technique for investigating the unsteady coherent structures responsible for the absorption of energy from the acoustic field. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Interaction between the acoustic pressure fluctuations and the unsteady flow field through circular holes [texte imprimé] / Jochen Rupp, Auteur ; Jon Carrotte, Auteur ; Adrian Spencer, Auteur . - 2011 . - 09 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 09 p. Mots-clés : Acoustic  intensity  measurement  Combustion  Damping  Ducts  Flow  Gas  turbines  Loudspeakers  Pressure  measurement Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Gas turbine combustion systems are prone to thermo-acoustic instabilities, and this is particularly the case for new low emission lean burn type systems. The presence of such instabilities is basically a function of the unsteady heat release within the system (i.e., both magnitude and phase) and the amount of damping. This paper is concerned with this latter process and the potential damping provided by perforated liners and other circular apertures found within gas turbine combustion systems. In particular, the paper outlines experimental measurements that characterize the flow field within the near field region of circular apertures when being subjected to incident acoustic pressure fluctuations. In this way the fundamental process by which acoustic energy is converted into kinetic energy of the velocity field can be investigated. Experimental results are presented for a single orifice located in an isothermal duct at ambient test conditions. Attached to the duct are two loudspeakers that provide pressure fluctuations incident onto the orifice. Unsteady pressure measurements enable the acoustic power absorbed by the orifice to be determined. This was undertaken for a range of excitation amplitudes and mean flows through the orifice. In this way regimes where both linear and nonlinear absorption occur along with the transition between these regimes can be investigated. The key to designing efficient passive dampers is to understand the interaction between the unsteady velocity field, generated at the orifice and the acoustic pressure fluctuations. Hence experimental techniques are also presented that enable such detailed measurements of the flow field to be made using particle image velocimetry. These measurements were obtained for conditions at which linear and nonlinear absorption was observed. Furthermore, proper orthogonal decomposition was used as a novel analysis technique for investigating the unsteady coherent structures responsible for the absorption of energy from the acoustic field. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

On the adequacy of chemiluminescence as a measure for heat release in turbulent flames with mixture gradients / Martin Lauer in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Titre : On the adequacy of chemiluminescence as a measure for heat release in turbulent flames with mixture gradients Type de document : texte imprimé Auteurs : Martin Lauer, Auteur ; Thomas Sattelmayer, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Chemiluminescence  Flames Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The determination of the heat release in technical flames is commonly done via bandpass filtered chemiluminescence measurements in the wavelength range of OH* or CH* radicals, which are supposed to be a measure for the heat release rate. However, these indirect heat release measurements are problematic because the measured intensities are the superposition of the desired radical emissions and contributions from the broadband emissions of CO2*. Furthermore, the chemiluminescence intensities are strongly affected by the local air excess ratio of the flame and the turbulence intensity in the reaction zone. To investigate the influence of these effects on the applicability of chemiluminescence as a measure for the heat release rate in turbulent flames with mixture gradients, a reference method is used, which is based on the first law of thermodynamics. It is shown that although the integral heat release can be correlated with the integral chemiluminescence intensities, the heat release distribution is not properly represented by any signal from OH* or CH*. No reliable information about the spatially resolved heat release can be obtained from chemiluminescence measurements in flames with mixture gradients. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] On the adequacy of chemiluminescence as a measure for heat release in turbulent flames with mixture gradients [texte imprimé] / Martin Lauer, Auteur ; Thomas Sattelmayer, Auteur . - 2011 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Mots-clés : Chemiluminescence  Flames Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The determination of the heat release in technical flames is commonly done via bandpass filtered chemiluminescence measurements in the wavelength range of OH* or CH* radicals, which are supposed to be a measure for the heat release rate. However, these indirect heat release measurements are problematic because the measured intensities are the superposition of the desired radical emissions and contributions from the broadband emissions of CO2*. Furthermore, the chemiluminescence intensities are strongly affected by the local air excess ratio of the flame and the turbulence intensity in the reaction zone. To investigate the influence of these effects on the applicability of chemiluminescence as a measure for the heat release rate in turbulent flames with mixture gradients, a reference method is used, which is based on the first law of thermodynamics. It is shown that although the integral heat release can be correlated with the integral chemiluminescence intensities, the heat release distribution is not properly represented by any signal from OH* or CH*. No reliable information about the spatially resolved heat release can be obtained from chemiluminescence measurements in flames with mixture gradients. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Impact of swirl fluctuations on the flame response of a perfectly premixed swirl burner / Thomas Komarek in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 07 p. Titre : Impact of swirl fluctuations on the flame response of a perfectly premixed swirl burner Type de document : texte imprimé Auteurs : Thomas Komarek, Auteur ; Wolfgang Polifke, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Flames  Swirling  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Combustion instabilities represent a long known problem in combustion technology. The complex interactions between acoustics and turbulent swirling flames are not fully understood yet, making it very difficult to reliably predict the stability of new combustion systems. For example, the effects of fluctuations of swirl number on the heat release of the flame have to be investigated in more detail. In this paper a perfectly premixed swirl stabilized burner with variable axial position of the swirl generator is investigated. In experiments, the position of the swirl generator has a strong impact on the dynamic flame response, although it does not influence the time-averaged distribution of the heat release significantly. This phenomenon is further investigated using computational fluid dynamics combined with system identification. The generation of fluctuations of swirl number, their propagation to the flame, and their effect on the dynamic flame response are examined. A simple model based on convective time lags is developed, showing good agreement with experiments. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Impact of swirl fluctuations on the flame response of a perfectly premixed swirl burner [texte imprimé] / Thomas Komarek, Auteur ; Wolfgang Polifke, Auteur . - 2011 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 07 p. Mots-clés : Flames  Swirling  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Combustion instabilities represent a long known problem in combustion technology. The complex interactions between acoustics and turbulent swirling flames are not fully understood yet, making it very difficult to reliably predict the stability of new combustion systems. For example, the effects of fluctuations of swirl number on the heat release of the flame have to be investigated in more detail. In this paper a perfectly premixed swirl stabilized burner with variable axial position of the swirl generator is investigated. In experiments, the position of the swirl generator has a strong impact on the dynamic flame response, although it does not influence the time-averaged distribution of the heat release significantly. This phenomenon is further investigated using computational fluid dynamics combined with system identification. The generation of fluctuations of swirl number, their propagation to the flame, and their effect on the dynamic flame response are examined. A simple model based on convective time lags is developed, showing good agreement with experiments. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Gas turbine engine emissions—Part I: Volatile organic compounds and nitrogen oxides / Michael T. Timko in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 14 p. Titre : Gas turbine engine emissions—Part I: Volatile organic compounds and nitrogen oxides Type de document : texte imprimé Auteurs : Michael T. Timko, Auteur ; Scott C. Herndon, Auteur ; Ezra C. Wood, Auteur Année de publication : 2011 Article en page(s) : 14 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Aerospace  engines  Aircraft  Gas  turbines  Organic  compounds Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The potential human health and environmental impacts of aircraft gas turbine engine emissions during normal airport operation are issues of growing concern. During the JETS/Aircraft Particle Emissions eXperiment(APEX)-2 and APEX-3 field campaigns, we performed an extensive series of gas phase and particulate emissions measurements of on-wing gas turbine engines. In all, nine different CFM56 style engines (including both CFM56-3B1 and -7B22 models) and seven additional engines (two RB211-535E4-B engines, three AE3007 engines, one PW4158, and one CJ6108A) were studied to evaluate engine-to-engine variability. Specific gas-phase measurements include NO2, NO, and total NOx, HCHO, C2H4, CO, and a range of volatile organic compounds (e.g., benzene, styrene, toluene, naphthalene). A number of broad conclusions can be made based on the gas-phase data set: (1) field measurements of gas-phase emission indices (EIs) are generally consistent with ICAO certification values; (2) speciation of gas phase NOx between NO and NO2 is reproducible for different engine types and favors NO2 at low power (and low fuel flow rate) and NO at high power (high fuel flow rate); (3) emission indices of gas-phase organic compounds and CO decrease rapidly with increasing fuel flow rate; (4) plotting EI-CO or volatile organic compound EIs against fuel flow rate collapses much of the variability between the different engines, with one exception (AE3007); (5) HCHO, ethylene, acetaldehyde, and propene are the most abundant volatile organic compounds present in the exhaust gases that we can detect, independent of engine technology differences. Empirical correlations accurate to within 30% and based on the publicly available engine parameters are presented for estimating EI-NOx and EI-NO2. Engine-to-engine variability, unavailability of combustor input conditions, changing ambient temperatures, and complex reaction dynamics limit the accuracy of global correlations for CO or volatile organic compound EIs. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Gas turbine engine emissions—Part I: Volatile organic compounds and nitrogen oxides [texte imprimé] / Michael T. Timko, Auteur ; Scott C. Herndon, Auteur ; Ezra C. Wood, Auteur . - 2011 . - 14 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 14 p. Mots-clés : Aerospace  engines  Aircraft  Gas  turbines  Organic  compounds Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The potential human health and environmental impacts of aircraft gas turbine engine emissions during normal airport operation are issues of growing concern. During the JETS/Aircraft Particle Emissions eXperiment(APEX)-2 and APEX-3 field campaigns, we performed an extensive series of gas phase and particulate emissions measurements of on-wing gas turbine engines. In all, nine different CFM56 style engines (including both CFM56-3B1 and -7B22 models) and seven additional engines (two RB211-535E4-B engines, three AE3007 engines, one PW4158, and one CJ6108A) were studied to evaluate engine-to-engine variability. Specific gas-phase measurements include NO2, NO, and total NOx, HCHO, C2H4, CO, and a range of volatile organic compounds (e.g., benzene, styrene, toluene, naphthalene). A number of broad conclusions can be made based on the gas-phase data set: (1) field measurements of gas-phase emission indices (EIs) are generally consistent with ICAO certification values; (2) speciation of gas phase NOx between NO and NO2 is reproducible for different engine types and favors NO2 at low power (and low fuel flow rate) and NO at high power (high fuel flow rate); (3) emission indices of gas-phase organic compounds and CO decrease rapidly with increasing fuel flow rate; (4) plotting EI-CO or volatile organic compound EIs against fuel flow rate collapses much of the variability between the different engines, with one exception (AE3007); (5) HCHO, ethylene, acetaldehyde, and propene are the most abundant volatile organic compounds present in the exhaust gases that we can detect, independent of engine technology differences. Empirical correlations accurate to within 30% and based on the publicly available engine parameters are presented for estimating EI-NOx and EI-NO2. Engine-to-engine variability, unavailability of combustor input conditions, changing ambient temperatures, and complex reaction dynamics limit the accuracy of global correlations for CO or volatile organic compound EIs. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Gas turbine engine emissions—Part II: Chemical properties of particulate matter / Michael T. Timko in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 15 p. Titre : Gas turbine engine emissions—Part II: Chemical properties of particulate matter Type de document : texte imprimé Auteurs : Michael T. Timko, Auteur ; Timothy B. Onasch, Auteur ; Megan J. Northway, Auteur Année de publication : 2011 Article en page(s) : 15 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Aerospace  engines  Cooling  Gas  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The characterization of volatile and nonvolatile particle materials present in gas turbine exhaust is critical for accurate estimation of the potential impacts of airport activities on local air quality, atmospheric processes, and climate change. Two field campaigns were performed to collect an extensive set of particle and gaseous emission data for on-wing gas turbine engines. The tests included CFM56, RB211-535E4-B, AE3007, PW4158, and CJ610 engines, providing the opportunity to compare emissions from a wide range of engine technologies. Here we report mass, number, composition, and size data for the nonvolatile (soot) and volatile particles present in engine exhaust. For all engines, soot emissions (EIm-soot) are greater at climbout (85% power) and takeoff (100%) power than idle (4% or 7%) and approach (30%). At the engine exit plane, soot is the only type of particle detected. For exhaust sampled downwind (15–50 m) and diluted by ambient air, total particle number emissions (EIn-total) increases by about one or two orders of magnitude relative to the engine exit plane, and the increase is driven by volatile particles that have freshly nucleated in the cooling exhaust gas both in the free atmosphere and in the extractive sample lines. Fuel sulfur content is the determining factor for nucleation of new particles in the cooling exhaust gases. Compositional analysis indicates that the volatile particles consist of sulfate and organic materials (EIm-sulfate and EIm-organic). We estimate a lower bound S[IV] to S[VI] conversion efficiency of (0.08±0.01)%, independent of engine technology. Measurements of EIm-organic ranged from about 0.1 mg kg−1 to 40 mg kg−1. Lubrication oil was present in particles emitted by all engines and accounted for over 90% of the particulate organic mass under some conditions. The products of incomplete combustion are a likely source of the remaining volatile organic particle material. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Gas turbine engine emissions—Part II: Chemical properties of particulate matter [texte imprimé] / Michael T. Timko, Auteur ; Timothy B. Onasch, Auteur ; Megan J. Northway, Auteur . - 2011 . - 15 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 15 p. Mots-clés : Aerospace  engines  Cooling  Gas  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The characterization of volatile and nonvolatile particle materials present in gas turbine exhaust is critical for accurate estimation of the potential impacts of airport activities on local air quality, atmospheric processes, and climate change. Two field campaigns were performed to collect an extensive set of particle and gaseous emission data for on-wing gas turbine engines. The tests included CFM56, RB211-535E4-B, AE3007, PW4158, and CJ610 engines, providing the opportunity to compare emissions from a wide range of engine technologies. Here we report mass, number, composition, and size data for the nonvolatile (soot) and volatile particles present in engine exhaust. For all engines, soot emissions (EIm-soot) are greater at climbout (85% power) and takeoff (100%) power than idle (4% or 7%) and approach (30%). At the engine exit plane, soot is the only type of particle detected. For exhaust sampled downwind (15–50 m) and diluted by ambient air, total particle number emissions (EIn-total) increases by about one or two orders of magnitude relative to the engine exit plane, and the increase is driven by volatile particles that have freshly nucleated in the cooling exhaust gas both in the free atmosphere and in the extractive sample lines. Fuel sulfur content is the determining factor for nucleation of new particles in the cooling exhaust gases. Compositional analysis indicates that the volatile particles consist of sulfate and organic materials (EIm-sulfate and EIm-organic). We estimate a lower bound S[IV] to S[VI] conversion efficiency of (0.08±0.01)%, independent of engine technology. Measurements of EIm-organic ranged from about 0.1 mg kg−1 to 40 mg kg−1. Lubrication oil was present in particles emitted by all engines and accounted for over 90% of the particulate organic mass under some conditions. The products of incomplete combustion are a likely source of the remaining volatile organic particle material. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Detailed numerical simulations of the primary atomization of a turbulent liquid jet in crossflow / Marcus Herrmann in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 10 p. Titre : Detailed numerical simulations of the primary atomization of a turbulent liquid jet in crossflow Type de document : texte imprimé Auteurs : Marcus Herrmann, Auteur Année de publication : 2011 Article en page(s) : 10 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Finite  volume  methods  Flow  simulation  Jets  Sprays  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents numerical simulation results of the primary atomization of a turbulent liquid jet injected into a gaseous crossflow. Simulations are performed using the balanced force refined level set grid method. The phase interface during the initial breakup phase is tracked by a level set method on a separate refined grid. A balanced force finite volume algorithm together with an interface projected curvature evaluation is used to ensure the stable and accurate treatment of surface tension forces even on small scales. Broken off, small scale nearly spherical drops are transferred into a Lagrangian point particle description allowing for full two-way coupling and continued secondary atomization. The numerical method is applied to the simulation of the primary atomization region of a turbulent liquid jet (q=6.6, We=330, Re=14,000) injected into a gaseous crossflow (Re=570,000), analyzed experimentally by Brown and McDonell (2006, “Near Field Behavior of a Liquid Jet in a Crossflow,” ILASS Americas, 19th Annual Conference on Liquid Atomization and Spray Systems). The simulations take the actual geometry of the injector into account. Grid converged simulation results of the jet penetration agree well with experimentally obtained correlations. Both column/bag breakup and shear/ligament breakup modes can be observed on the liquid jet. A grid refinement study shows that on the finest employed grids (flow solver 64 points per injector diameter, level set solver 128 points per injector diameter), grid converged drop sizes are achieved for drops as small as one-hundredth the size of the injector diameter. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Detailed numerical simulations of the primary atomization of a turbulent liquid jet in crossflow [texte imprimé] / Marcus Herrmann, Auteur . - 2011 . - 10 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 10 p. Mots-clés : Finite  volume  methods  Flow  simulation  Jets  Sprays  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents numerical simulation results of the primary atomization of a turbulent liquid jet injected into a gaseous crossflow. Simulations are performed using the balanced force refined level set grid method. The phase interface during the initial breakup phase is tracked by a level set method on a separate refined grid. A balanced force finite volume algorithm together with an interface projected curvature evaluation is used to ensure the stable and accurate treatment of surface tension forces even on small scales. Broken off, small scale nearly spherical drops are transferred into a Lagrangian point particle description allowing for full two-way coupling and continued secondary atomization. The numerical method is applied to the simulation of the primary atomization region of a turbulent liquid jet (q=6.6, We=330, Re=14,000) injected into a gaseous crossflow (Re=570,000), analyzed experimentally by Brown and McDonell (2006, “Near Field Behavior of a Liquid Jet in a Crossflow,” ILASS Americas, 19th Annual Conference on Liquid Atomization and Spray Systems). The simulations take the actual geometry of the injector into account. Grid converged simulation results of the jet penetration agree well with experimentally obtained correlations. Both column/bag breakup and shear/ligament breakup modes can be observed on the liquid jet. A grid refinement study shows that on the finest employed grids (flow solver 64 points per injector diameter, level set solver 128 points per injector diameter), grid converged drop sizes are achieved for drops as small as one-hundredth the size of the injector diameter. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Three-stream flamelet model for industrial applications / Dirk Riechelmann in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Titre : Three-stream flamelet model for industrial applications Type de document : texte imprimé Auteurs : Dirk Riechelmann, Auteur ; Masahiro Uchida, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Combustion  Diffusion  Flames  Numerical  analysis  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Efficient turbulent combustion models are typically designed for the numerical simulation of two-stream problems, namely, the combustion of fuel in air. There are applications, however, where large amounts of a diluent such as water steam or recirculated exhaust gas is supplied to the combustor independent of fuel and air supplies. In such cases, classical approaches become quite time-consuming. In the present paper, a new three-stream flamelet model is presented, which is essentially an extension of the two-stream flamelet model for diffusion flames. Key points of the approach are the introduction of a second mixture fraction variable and the efficient establishment of the flamelet library. After presentation of the theory, the applicability of the new model is demonstrated by comparison with experimental results for the lift-off height of jet diffusion flames. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Three-stream flamelet model for industrial applications [texte imprimé] / Dirk Riechelmann, Auteur ; Masahiro Uchida, Auteur . - 2011 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Mots-clés : Combustion  Diffusion  Flames  Numerical  analysis  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Efficient turbulent combustion models are typically designed for the numerical simulation of two-stream problems, namely, the combustion of fuel in air. There are applications, however, where large amounts of a diluent such as water steam or recirculated exhaust gas is supplied to the combustor independent of fuel and air supplies. In such cases, classical approaches become quite time-consuming. In the present paper, a new three-stream flamelet model is presented, which is essentially an extension of the two-stream flamelet model for diffusion flames. Key points of the approach are the introduction of a second mixture fraction variable and the efficient establishment of the flamelet library. After presentation of the theory, the applicability of the new model is demonstrated by comparison with experimental results for the lift-off height of jet diffusion flames. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Combined cycles with CO2 capture / Nikolett Sipöcz in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 06 p. Titre : Combined cycles with CO2 capture : two alternatives for system integration Type de document : texte imprimé Auteurs : Nikolett Sipöcz, Auteur ; Mohsen Assadi, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Air  pollution  control  Biofuel  Boilers  Combined  cycle  power  stations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : As carbon capture and storage technology has grown as a promising option to significantly reduce CO2 emissions, system integration and optimization claim an important and crucial role. This paper presents a comparative study of a gas turbine cycle with postcombustion CO2 separation using an amine-based absorption process with monoethanolamine. The study has been made for a triple pressure reheated 400 MWe natural gas-fuelled combined cycle with exhaust gas recirculation (EGR) to improve capture efficiency. Two different options for the energy supply to the solvent regeneration have been evaluated and compared concerning plant performance. In the first alternative heat is provided by steam extracted internally from the bottoming steam cycle, while in the second option an external biomass-fuelled boiler was utilized to generate the required heat. With this novel configuration the amount of CO2 captured can be even more than 100% if the exhaust gas from the biofuelled boiler is mixed and cleaned together with the main exhaust gas flow from the combined cycle. In order to make an unprejudiced comparison between the two alternatives, the reduced steam turbine efficiency has been taken into consideration and estimated, for the alternative with internal steam extraction. The cycles have been modeled in the commercial heat and mass balance program IPSEPROTM using detailed component models. Utilizing EGR can double the CO2 content of the exhaust gases and reduce the energy need for the separation process by approximately 2% points. Using an external biomass-fuelled boiler as heat source for amine regeneration turns out to be an interesting option due to high CO2 capture effectiveness. However the electrical efficiency of the power plant is reduced compared with the option with internal steam extraction. Another drawback with the external boiler is the higher investment costs but nevertheless, it is flexibility due to the independency from the rest of the power generation system represents a major operational advantage. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Combined cycles with CO2 capture : two alternatives for system integration [texte imprimé] / Nikolett Sipöcz, Auteur ; Mohsen Assadi, Auteur . - 2011 . - 06 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 06 p. Mots-clés : Air  pollution  control  Biofuel  Boilers  Combined  cycle  power  stations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : As carbon capture and storage technology has grown as a promising option to significantly reduce CO2 emissions, system integration and optimization claim an important and crucial role. This paper presents a comparative study of a gas turbine cycle with postcombustion CO2 separation using an amine-based absorption process with monoethanolamine. The study has been made for a triple pressure reheated 400 MWe natural gas-fuelled combined cycle with exhaust gas recirculation (EGR) to improve capture efficiency. Two different options for the energy supply to the solvent regeneration have been evaluated and compared concerning plant performance. In the first alternative heat is provided by steam extracted internally from the bottoming steam cycle, while in the second option an external biomass-fuelled boiler was utilized to generate the required heat. With this novel configuration the amount of CO2 captured can be even more than 100% if the exhaust gas from the biofuelled boiler is mixed and cleaned together with the main exhaust gas flow from the combined cycle. In order to make an unprejudiced comparison between the two alternatives, the reduced steam turbine efficiency has been taken into consideration and estimated, for the alternative with internal steam extraction. The cycles have been modeled in the commercial heat and mass balance program IPSEPROTM using detailed component models. Utilizing EGR can double the CO2 content of the exhaust gases and reduce the energy need for the separation process by approximately 2% points. Using an external biomass-fuelled boiler as heat source for amine regeneration turns out to be an interesting option due to high CO2 capture effectiveness. However the electrical efficiency of the power plant is reduced compared with the option with internal steam extraction. Another drawback with the external boiler is the higher investment costs but nevertheless, it is flexibility due to the independency from the rest of the power generation system represents a major operational advantage. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Application of the geared turbofan with constant volume combustor on short-range aircraft / Ramón F. Colmenares Quintero in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Titre : Application of the geared turbofan with constant volume combustor on short-range aircraft : a feasibility study Type de document : texte imprimé Auteurs : Ramón F. Colmenares Quintero, Auteur ; Rob Brink, Auteur ; Stephen Ogaji, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Aircraft  Gas  turbines  Jet  engines  Monte  Carlo  methods  Thermodynamics Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behavior. Wave rotor combustion provides semiconstant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary multidisciplinary design framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions, and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, the acquisition cost of the engine is higher, but the engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emission requirements. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Application of the geared turbofan with constant volume combustor on short-range aircraft : a feasibility study [texte imprimé] / Ramón F. Colmenares Quintero, Auteur ; Rob Brink, Auteur ; Stephen Ogaji, Auteur . - 2011 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Mots-clés : Aircraft  Gas  turbines  Jet  engines  Monte  Carlo  methods  Thermodynamics Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behavior. Wave rotor combustion provides semiconstant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary multidisciplinary design framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions, and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, the acquisition cost of the engine is higher, but the engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emission requirements. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Comparison of preanode and postanode carbon dioxide separation for IGFC systems / Eric Liese in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Titre : Comparison of preanode and postanode carbon dioxide separation for IGFC systems Type de document : texte imprimé Auteurs : Eric Liese, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Air  pollution  control  Anodes  Carbon  compounds  Cathodes  Fuel  cell  power  plants  Gas  turbines  Solid  oxide  fuel  cells Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper examines the arrangement of a solid oxide fuel cell (SOFC) within a coal gasification cycle, this combination generally being called an integrated gasification fuel cell cycle. This work relies on a previous study performed by the National Energy Technology Laboratory (NETL) that details thermodynamic simulations of integrated gasification combined cycle (IGCC) systems and considers various gasifier types and includes cases for 90% CO2 capture (2007, “Cost and Performance Baseline for Fossil Energy Plants, Vol. 1: Bituminous Coal and Natural Gas to Electricity,” National Energy Technology Laboratory Report No. DOE/NETL-2007/1281). All systems in this study assume a Conoco Philips gasifier and cold-gas clean up conditions for the coal gasification system (Cases 3 and 4 in the NETL IGCC report). Four system arrangements, cases, are examined. Cases 1 and 2 remove the CO2 after the SOFC anode. Case 3 assumes steam addition, a water-gas-shift (WGS) catalyst, and a Selexol process to remove the CO2 in the gas cleanup section, sending a hydrogen-rich gas to the fuel cell anode. Case 4 assumes Selexol in the cold-gas cleanup section as in Case 3; however, there is no steam addition, and the WGS takes places in the SOFC and after the anode. Results demonstrate significant efficiency advantages compared with IGCC with CO2 capture. The hydrogen-rich case (Case 3) has better net electric efficiency compared with typical postanode CO2 capture cases (Cases 1 and 2), with a simpler arrangement but at a lower SOFC power density, or a lower efficiency at the same power density. Case 4 gives an efficiency similar to Case 3 but also at a lower SOFC power density. Carbon deposition concerns are also discussed. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Comparison of preanode and postanode carbon dioxide separation for IGFC systems [texte imprimé] / Eric Liese, Auteur . - 2011 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Mots-clés : Air  pollution  control  Anodes  Carbon  compounds  Cathodes  Fuel  cell  power  plants  Gas  turbines  Solid  oxide  fuel  cells Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper examines the arrangement of a solid oxide fuel cell (SOFC) within a coal gasification cycle, this combination generally being called an integrated gasification fuel cell cycle. This work relies on a previous study performed by the National Energy Technology Laboratory (NETL) that details thermodynamic simulations of integrated gasification combined cycle (IGCC) systems and considers various gasifier types and includes cases for 90% CO2 capture (2007, “Cost and Performance Baseline for Fossil Energy Plants, Vol. 1: Bituminous Coal and Natural Gas to Electricity,” National Energy Technology Laboratory Report No. DOE/NETL-2007/1281). All systems in this study assume a Conoco Philips gasifier and cold-gas clean up conditions for the coal gasification system (Cases 3 and 4 in the NETL IGCC report). Four system arrangements, cases, are examined. Cases 1 and 2 remove the CO2 after the SOFC anode. Case 3 assumes steam addition, a water-gas-shift (WGS) catalyst, and a Selexol process to remove the CO2 in the gas cleanup section, sending a hydrogen-rich gas to the fuel cell anode. Case 4 assumes Selexol in the cold-gas cleanup section as in Case 3; however, there is no steam addition, and the WGS takes places in the SOFC and after the anode. Results demonstrate significant efficiency advantages compared with IGCC with CO2 capture. The hydrogen-rich case (Case 3) has better net electric efficiency compared with typical postanode CO2 capture cases (Cases 1 and 2), with a simpler arrangement but at a lower SOFC power density, or a lower efficiency at the same power density. Case 4 gives an efficiency similar to Case 3 but also at a lower SOFC power density. Carbon deposition concerns are also discussed. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Analysis of compressor on-line washing to optimize gas turbine power plant performance / Ernst Schneider in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 07 p. Titre : Analysis of compressor on-line washing to optimize gas turbine power plant performance Type de document : texte imprimé Auteurs : Ernst Schneider, Auteur ; Saba Demircioglu Bussjaeger, Auteur ; Susana Franco, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Blades  Compressors  Gas  turbines  Wear Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Due to compressor fouling, gas turbine efficiency decreases over time, resulting in decreased power output of the plant. To counteract the effects of compressor fouling, compressor on-line and off-line washing procedures are used. The effectiveness of compressor off-line washing is enhanced if combined with the cleaning of the VIGVs and the first compressor blade row by hand. This paper presents a thorough analysis of the effects of compressor on-line washing on the gas turbine performance. The analysis is based on the measured data of six gas turbines operated at two different plants. Different washing schedules and washing fluids are analyzed and compared. Furthermore, the effects of compressor on-line washing on the load distribution within the compressor are analyzed. The performance benefit of daily compressor on-line washing compared with weekly compressor on-line washing is quantified. As expected, daily compressor on-line washing yields the lowest power degradation caused by compressor fouling. Also, the effect of washing additives is analyzed. It is shown with long term data that compressor on-line washing cleans up to the first 11 compressor stages, as can be detected well in the compressor. With a view to gas turbine performance optimization, the recommendation is to perform compressor off-line washing at regular intervals and to take advantage of occasions such as inspections, when the gas turbine is cooled down anyhow. Especially for gas turbines with a high fouling rate, a daily compressor on-line washing schedule should be considered to reduce the power loss. For gas turbines operating with high fogging, compressor on-line washing has no added benefit. To determine the optimal compressor washing schedule, compressor blade erosion also has to be considered. A reasonable balance between compressor on-line washing and off-line washing improves the gas turbine performance and optimizes the gas turbine availability. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Analysis of compressor on-line washing to optimize gas turbine power plant performance [texte imprimé] / Ernst Schneider, Auteur ; Saba Demircioglu Bussjaeger, Auteur ; Susana Franco, Auteur . - 2011 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 07 p. Mots-clés : Blades  Compressors  Gas  turbines  Wear Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Due to compressor fouling, gas turbine efficiency decreases over time, resulting in decreased power output of the plant. To counteract the effects of compressor fouling, compressor on-line and off-line washing procedures are used. The effectiveness of compressor off-line washing is enhanced if combined with the cleaning of the VIGVs and the first compressor blade row by hand. This paper presents a thorough analysis of the effects of compressor on-line washing on the gas turbine performance. The analysis is based on the measured data of six gas turbines operated at two different plants. Different washing schedules and washing fluids are analyzed and compared. Furthermore, the effects of compressor on-line washing on the load distribution within the compressor are analyzed. The performance benefit of daily compressor on-line washing compared with weekly compressor on-line washing is quantified. As expected, daily compressor on-line washing yields the lowest power degradation caused by compressor fouling. Also, the effect of washing additives is analyzed. It is shown with long term data that compressor on-line washing cleans up to the first 11 compressor stages, as can be detected well in the compressor. With a view to gas turbine performance optimization, the recommendation is to perform compressor off-line washing at regular intervals and to take advantage of occasions such as inspections, when the gas turbine is cooled down anyhow. Especially for gas turbines with a high fouling rate, a daily compressor on-line washing schedule should be considered to reduce the power loss. For gas turbines operating with high fogging, compressor on-line washing has no added benefit. To determine the optimal compressor washing schedule, compressor blade erosion also has to be considered. A reasonable balance between compressor on-line washing and off-line washing improves the gas turbine performance and optimizes the gas turbine availability. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Effect of tungsten addition on the nucleation of borides in wide gap brazed joint / Daniel McGuire in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 06 p. Titre : Effect of tungsten addition on the nucleation of borides in wide gap brazed joint Type de document : texte imprimé Auteurs : Daniel McGuire, Auteur ; Huang, Xiao, Auteur ; Doug Nagy, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Brazing  Ductility  Gas  turbines  Maintenance  engineering  Mechanical  alloying  Superalloys  Thermal  stress  cracking  Tungsten Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Wide gap brazing (WGB) is a cost effective and reliable means to repair gas turbine hot section components with defect sizes exceeding 0.3 mm. However, it has been shown that WGB joints of nickel-based superalloys suffer from reduced ductility and thermal fatigue life due to the presence of brittle intermetallics and porosities in the brazed joint. In order to disperse the brittle intermetallic compounds, potentially increase the ductility of the repaired region, and reduce the risk of the thermomechanical fatigue failure, elemental tungsten (W) was added to the braze additive filler alloy IN738 by mechanical alloying. The alloyed IN738 was then brazed with the addition of 30 wt %, 50 wt %, and 80 wt % of braze alloy (BNi-9). After brazing at 1200°C for 20 min, microstructural analysis of WGB joints showed a decreasing trend of discrete boride size and the amount of eutectic and script-shaped borides with the increases of W. The increase in the braze alloy to additive filler alloy ratio diminished the effect of W addition due the dissolution of W particulates. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Effect of tungsten addition on the nucleation of borides in wide gap brazed joint [texte imprimé] / Daniel McGuire, Auteur ; Huang, Xiao, Auteur ; Doug Nagy, Auteur . - 2011 . - 06 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 06 p. Mots-clés : Brazing  Ductility  Gas  turbines  Maintenance  engineering  Mechanical  alloying  Superalloys  Thermal  stress  cracking  Tungsten Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Wide gap brazing (WGB) is a cost effective and reliable means to repair gas turbine hot section components with defect sizes exceeding 0.3 mm. However, it has been shown that WGB joints of nickel-based superalloys suffer from reduced ductility and thermal fatigue life due to the presence of brittle intermetallics and porosities in the brazed joint. In order to disperse the brittle intermetallic compounds, potentially increase the ductility of the repaired region, and reduce the risk of the thermomechanical fatigue failure, elemental tungsten (W) was added to the braze additive filler alloy IN738 by mechanical alloying. The alloyed IN738 was then brazed with the addition of 30 wt %, 50 wt %, and 80 wt % of braze alloy (BNi-9). After brazing at 1200°C for 20 min, microstructural analysis of WGB joints showed a decreasing trend of discrete boride size and the amount of eutectic and script-shaped borides with the increases of W. The increase in the braze alloy to additive filler alloy ratio diminished the effect of W addition due the dissolution of W particulates. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

The thermal impact of using syngas as fuel in the regenerator of regenerative gas turbine engine / Luciana M. Oliveira in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Titre : The thermal impact of using syngas as fuel in the regenerator of regenerative gas turbine engine Type de document : texte imprimé Auteurs : Luciana M. Oliveira, Auteur ; Marco A. R. Nascimento, Auteur ; Genésio J. Menon, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Bioenergy  conversion  Gas  turbines  Heat  transfer  Natural  gas  technology Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Environment and energy are driven forces of human survival and development. Nowadays the use of primary energy comprises mostly mineral fuels, which have limited reserves and whose utilization may cause serious environmental impacts. Attention has been paid to discover clean and renewable resources such as syngas, which is an important renewable source of energy and is environment friendly. The use of syngas from biomass gasification process as fuel in regenerative gas turbine causes an increase in turbine exhaust mass flow and a change in the gas composition due to a low heat value. As a result, the regenerator changes its size, thermal characteristics, weight, and cost compared with the use of natural gas as fuel. The aim of this work is to assess the thermal performance, the size, and the cost of the recuperator of a 600 kW regenerative gas turbine engine when designed for syngas and natural gas. Two different types of surfaces, cross-corrugated and undulated-corrugated, are used for analysis. The results are shown, comparing heat-transfer coefficient, effectiveness, pressure loss, size, and cost for syngas and natural gas. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] The thermal impact of using syngas as fuel in the regenerator of regenerative gas turbine engine [texte imprimé] / Luciana M. Oliveira, Auteur ; Marco A. R. Nascimento, Auteur ; Genésio J. Menon, Auteur . - 2011 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 08 p. Mots-clés : Bioenergy  conversion  Gas  turbines  Heat  transfer  Natural  gas  technology Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Environment and energy are driven forces of human survival and development. Nowadays the use of primary energy comprises mostly mineral fuels, which have limited reserves and whose utilization may cause serious environmental impacts. Attention has been paid to discover clean and renewable resources such as syngas, which is an important renewable source of energy and is environment friendly. The use of syngas from biomass gasification process as fuel in regenerative gas turbine causes an increase in turbine exhaust mass flow and a change in the gas composition due to a low heat value. As a result, the regenerator changes its size, thermal characteristics, weight, and cost compared with the use of natural gas as fuel. The aim of this work is to assess the thermal performance, the size, and the cost of the recuperator of a 600 kW regenerative gas turbine engine when designed for syngas and natural gas. Two different types of surfaces, cross-corrugated and undulated-corrugated, are used for analysis. The results are shown, comparing heat-transfer coefficient, effectiveness, pressure loss, size, and cost for syngas and natural gas. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Experimental evaluation of the transient behavior of a compressor station during emergency shutdowns / J. Jeffrey Moore in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 09 p. Titre : Experimental evaluation of the transient behavior of a compressor station during emergency shutdowns Type de document : texte imprimé Auteurs : J. Jeffrey Moore, Auteur ; Rainer Kurz, Auteur ; Augusto Garcia-Hernandez, Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Compressors  Confined  flow  Flow  instability  Surges  Transient  analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The transient behavior of compressor stations, particularly under rapidly changing conditions, is of vital interest to operators. Predicting transient behavior is an important factor in avoiding damage during events such as emergency shutdowns. A limited number of “accidental” data sets from compressor manufacturers and users are available in the public literature domain. A variety of simulations and modeling approaches have been presented over the last few years at industry conferences. The available experimental data is not of sufficient quality and resolution to properly compare predictions with analytical results or simulations available in current software packages. Necessary information about the compressor, driver, valves, and geometry of the system is often missing. Currently utilized software has not been adequately validated with full-scale realistic benchmark data, as this data is not available in the public domain. Modeling procedures and results of surge control system simulations seldom contain validation data achieved through actual testing. This type of transient test data for a dynamic surge condition is often difficult to obtain. The primary objective of this work is to develop experimental transient compressor surge data on a full-scale test facility, which would facilitate the verification and comparison of existing and future transient surge models. Results of the testing and model comparisons will be documented. Relevant, dimensionless parameters will be presented and validated utilizing the test data. Conclusions from the testing and recommendations for the transient analysis software will be provided. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Experimental evaluation of the transient behavior of a compressor station during emergency shutdowns [texte imprimé] / J. Jeffrey Moore, Auteur ; Rainer Kurz, Auteur ; Augusto Garcia-Hernandez, Auteur . - 2011 . - 09 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 09 p. Mots-clés : Compressors  Confined  flow  Flow  instability  Surges  Transient  analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The transient behavior of compressor stations, particularly under rapidly changing conditions, is of vital interest to operators. Predicting transient behavior is an important factor in avoiding damage during events such as emergency shutdowns. A limited number of “accidental” data sets from compressor manufacturers and users are available in the public literature domain. A variety of simulations and modeling approaches have been presented over the last few years at industry conferences. The available experimental data is not of sufficient quality and resolution to properly compare predictions with analytical results or simulations available in current software packages. Necessary information about the compressor, driver, valves, and geometry of the system is often missing. Currently utilized software has not been adequately validated with full-scale realistic benchmark data, as this data is not available in the public domain. Modeling procedures and results of surge control system simulations seldom contain validation data achieved through actual testing. This type of transient test data for a dynamic surge condition is often difficult to obtain. The primary objective of this work is to develop experimental transient compressor surge data on a full-scale test facility, which would facilitate the verification and comparison of existing and future transient surge models. Results of the testing and model comparisons will be documented. Relevant, dimensionless parameters will be presented and validated utilizing the test data. Conclusions from the testing and recommendations for the transient analysis software will be provided. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Assessment of compressors in gas storage applications / Rainer Kurz in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 07 p. Titre : Assessment of compressors in gas storage applications Type de document : texte imprimé Auteurs : Rainer Kurz, Auteur ; Klaus Brun, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Compressors  Gas  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An analytical model is generated that allows the evaluation of the compression system. It is also used to derive general rules for optimizing a system. Several strategies for the compression system (single compressors, multiple compressors with a single driver in series and parallel configuration, and multiple compressors with individual drivers) are evaluated based on the said model. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Assessment of compressors in gas storage applications [texte imprimé] / Rainer Kurz, Auteur ; Klaus Brun, Auteur . - 2011 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 07 p. Mots-clés : Compressors  Gas  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An analytical model is generated that allows the evaluation of the compression system. It is also used to derive general rules for optimizing a system. Several strategies for the compression system (single compressors, multiple compressors with a single driver in series and parallel configuration, and multiple compressors with individual drivers) are evaluated based on the said model. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Numerical investigations on leakage performance of the rotating labyrinth honeycomb seal / Shengru Kong in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 11 p. Titre : Numerical investigations on leakage performance of the rotating labyrinth honeycomb seal Type de document : texte imprimé Auteurs : Shengru Kong, Auteur ; Xin Yan, Auteur ; Shinnosuke Obi, Auteur Année de publication : 2011 Article en page(s) : 11 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Flow  simulation  Honeycomb  structures  Navier-Stokes  equations  Seals  (stoppers) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Three-dimensional Reynolds-averaged Navier–Stokes (RANS) solutions from CFX were utilized to investigate the leakage flow characteristics in the labyrinth honeycomb seal of steam turbines. At first, the accuracy and reliability of the utilized RANS approach was demonstrated using the published experimental data of the honeycomb seal. It showed that the utilized numerical method has sufficient precision to predict the leakage performance in seals. Then a range of sealing clearances, cell diameters, cell depths, rotation speeds, and pressure ratios were investigated to determine how these factors affect the leakage flow rate of the labyrinth honeycomb seal. The computed leakage flow rate increased with increasing sealing clearance and pressure ratios. Furthermore, the results show that the studied labyrinth honeycomb seal has the optimum sealing performance in the case of honeycomb cell diameter equals labyrinth step width, and the ratio of the honeycomb cell depth to honeycomb cell diameter is 0.93 under the designed condition. The flow pattern of each case is also illustrated to describe the leakage flow characteristics in labyrinth honeycomb seals. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Numerical investigations on leakage performance of the rotating labyrinth honeycomb seal [texte imprimé] / Shengru Kong, Auteur ; Xin Yan, Auteur ; Shinnosuke Obi, Auteur . - 2011 . - 11 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 11 p. Mots-clés : Flow  simulation  Honeycomb  structures  Navier-Stokes  equations  Seals  (stoppers) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Three-dimensional Reynolds-averaged Navier–Stokes (RANS) solutions from CFX were utilized to investigate the leakage flow characteristics in the labyrinth honeycomb seal of steam turbines. At first, the accuracy and reliability of the utilized RANS approach was demonstrated using the published experimental data of the honeycomb seal. It showed that the utilized numerical method has sufficient precision to predict the leakage performance in seals. Then a range of sealing clearances, cell diameters, cell depths, rotation speeds, and pressure ratios were investigated to determine how these factors affect the leakage flow rate of the labyrinth honeycomb seal. The computed leakage flow rate increased with increasing sealing clearance and pressure ratios. Furthermore, the results show that the studied labyrinth honeycomb seal has the optimum sealing performance in the case of honeycomb cell diameter equals labyrinth step width, and the ratio of the honeycomb cell depth to honeycomb cell diameter is 0.93 under the designed condition. The flow pattern of each case is also illustrated to describe the leakage flow characteristics in labyrinth honeycomb seals. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

A method for forced response analysis of mistuned bladed disks with aerodynamic effects included / E. P. Petrov in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 10 p. Titre : A method for forced response analysis of mistuned bladed disks with aerodynamic effects included Type de document : texte imprimé Auteurs : E. P. Petrov, Auteur Année de publication : 2011 Article en page(s) : 10 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Aerodynamics  Blades  Damping  Frequency  response  Vibrations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A method has been developed for high-accuracy analysis of forced response levels for mistuned bladed disks vibrating in gas flow. Aerodynamic damping, the interaction of vibrating blades through gas flow, and the effects of structural and aerodynamic mistuning are included in the bladed disk model. The method is applicable to cases of high mechanical coupling of blade vibration through a flexible disk and, possibly shrouds, to cases with stiff disks and low mechanical coupling. The interaction of different families of bladed disk modes is included in the analysis providing the capability of analyzing bladed disks with pronounced frequency veering effects. The method allows the use of industrial-size sector models of bladed disks for analysis of forced response of a mistuned structure. The frequency response function matrix of a structurally mistuned bladed disk is derived with aerodynamic forces included. A new phenomenon of reducing bladed disk forced response by mistuning to levels that are several times lower than those of their tuned counterparts is revealed and explained. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] A method for forced response analysis of mistuned bladed disks with aerodynamic effects included [texte imprimé] / E. P. Petrov, Auteur . - 2011 . - 10 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 10 p. Mots-clés : Aerodynamics  Blades  Damping  Frequency  response  Vibrations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A method has been developed for high-accuracy analysis of forced response levels for mistuned bladed disks vibrating in gas flow. Aerodynamic damping, the interaction of vibrating blades through gas flow, and the effects of structural and aerodynamic mistuning are included in the bladed disk model. The method is applicable to cases of high mechanical coupling of blade vibration through a flexible disk and, possibly shrouds, to cases with stiff disks and low mechanical coupling. The interaction of different families of bladed disk modes is included in the analysis providing the capability of analyzing bladed disks with pronounced frequency veering effects. The method allows the use of industrial-size sector models of bladed disks for analysis of forced response of a mistuned structure. The frequency response function matrix of a structurally mistuned bladed disk is derived with aerodynamic forces included. A new phenomenon of reducing bladed disk forced response by mistuning to levels that are several times lower than those of their tuned counterparts is revealed and explained. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Experimental study on fault caused by partial arc steam forces and its economic solution / Daren Yu in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 04 p. Titre : Experimental study on fault caused by partial arc steam forces and its economic solution Type de document : texte imprimé Auteurs : Daren Yu, Auteur ; Yanfeng Duan, Auteur ; Jinfu Liu, Auteur Année de publication : 2011 Article en page(s) : 04 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Fault  diagnosis  Machine  bearings  Steam  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : It is noticed in a few steam turbines that there are a pad temperature rise of more than 10°C and a radial journal movement of more than 50 µm in the bearings adjacent to control stage when they operate under partial arc admission at 60–80% of their full load. It is found through fault mechanism analysis and experimental study that the fault is caused by partial arc steam forces acting on control stage. A fault characteristic is concluded to help identify this fault. Diagonal admission is therefore proposed as an economic solution for elimination of this fault and it is proved to be effective through practical test. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Experimental study on fault caused by partial arc steam forces and its economic solution [texte imprimé] / Daren Yu, Auteur ; Yanfeng Duan, Auteur ; Jinfu Liu, Auteur . - 2011 . - 04 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 04 p. Mots-clés : Fault  diagnosis  Machine  bearings  Steam  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : It is noticed in a few steam turbines that there are a pad temperature rise of more than 10°C and a radial journal movement of more than 50 µm in the bearings adjacent to control stage when they operate under partial arc admission at 60–80% of their full load. It is found through fault mechanism analysis and experimental study that the fault is caused by partial arc steam forces acting on control stage. A fault characteristic is concluded to help identify this fault. Diagonal admission is therefore proposed as an economic solution for elimination of this fault and it is proved to be effective through practical test. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Spreadsheet calculations for jets in crossflow from single and opposed rows with alternating hole sizes / J. D. Holdeman in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 07 p. Titre : Spreadsheet calculations for jets in crossflow from single and opposed rows with alternating hole sizes Type de document : texte imprimé Auteurs : J. D. Holdeman, Auteur ; J. R. Clisset, Auteur ; J. P. Moder, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Flow  Jets Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The primary purpose of this study was to show the expected results for cases of single and opposed rows of jets from alternating large and small round holes. Previous publications demonstrated that the NASA empirical model gave results that were an excellent representation of mean experimental scalar results and that the model could confidently be used to investigate configurations for which results have not been published in the open literature. Calculations for cases of opposed rows of jets that would overpenetrate slightly in an inline configuration showed that better mixing was attained when one row was shifted to make a staggered configuration so that a small hole was opposite from a larger one. However, the result was no better than for an optimum inline configuration with all the holes of the same size. Staggering the rows does not make much difference in an optimum inline configuration. For all cases investigated, the dimensionless variance of the mixture fraction decreased significantly with increasing downstream distance, but, at a given downstream location, the variation between cases was small. DEWEY : 62.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Spreadsheet calculations for jets in crossflow from single and opposed rows with alternating hole sizes [texte imprimé] / J. D. Holdeman, Auteur ; J. R. Clisset, Auteur ; J. P. Moder, Auteur . - 2011 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 07 p. Mots-clés : Flow  Jets Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The primary purpose of this study was to show the expected results for cases of single and opposed rows of jets from alternating large and small round holes. Previous publications demonstrated that the NASA empirical model gave results that were an excellent representation of mean experimental scalar results and that the model could confidently be used to investigate configurations for which results have not been published in the open literature. Calculations for cases of opposed rows of jets that would overpenetrate slightly in an inline configuration showed that better mixing was attained when one row was shifted to make a staggered configuration so that a small hole was opposite from a larger one. However, the result was no better than for an optimum inline configuration with all the holes of the same size. Staggering the rows does not make much difference in an optimum inline configuration. For all cases investigated, the dimensionless variance of the mixture fraction decreased significantly with increasing downstream distance, but, at a given downstream location, the variation between cases was small. DEWEY : 62.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Comparative performance, emission, and combustion characteristics of rice-bran oil and its biodiesel in a transportation diesel engine / Avinash Kumar Agarwal in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 04 p. Titre : Comparative performance, emission, and combustion characteristics of rice-bran oil and its biodiesel in a transportation diesel engine Type de document : texte imprimé Auteurs : Avinash Kumar Agarwal, Auteur ; Atul Dhar, Auteur Année de publication : 2011 Article en page(s) : 04 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Biofuel  Combustion  Diesel  engines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The methyl esters of vegetable oils known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engines. Methyl ester of rice-bran oil (RBOME) is prepared through the process of transesterification. In the present investigation, experiments have been carried out to examine the performance, emission, and combustion characteristics of a direct-injection transportation diesel engine running with diesel, 20% blend of rice-bran oil (RBO), and 20% blend of RBOME with mineral diesel. A four-stroke, four-cylinder, direct-injection transportation diesel engine (MDI 3000) was instrumented for the measurement of the engine performance, emissions, in-cylinder pressure-crank angle history, rate of pressure rise, and other important combustion parameters such as instantaneous heat release rate, cumulative heat release rate, mass fraction burned, etc. A careful analysis of the performance, emissions, combustion, and heat release parameters has been carried out. HC, CO, and smoke emissions for RBO and RBOME blends were lower than mineral diesel while NOx emissions were almost similar and brake specific fuel consumption (BSFC) was slightly higher than mineral diesel. Combustion characteristics were quite similar for the three fuels. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Comparative performance, emission, and combustion characteristics of rice-bran oil and its biodiesel in a transportation diesel engine [texte imprimé] / Avinash Kumar Agarwal, Auteur ; Atul Dhar, Auteur . - 2011 . - 04 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 04 p. Mots-clés : Biofuel  Combustion  Diesel  engines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The methyl esters of vegetable oils known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engines. Methyl ester of rice-bran oil (RBOME) is prepared through the process of transesterification. In the present investigation, experiments have been carried out to examine the performance, emission, and combustion characteristics of a direct-injection transportation diesel engine running with diesel, 20% blend of rice-bran oil (RBO), and 20% blend of RBOME with mineral diesel. A four-stroke, four-cylinder, direct-injection transportation diesel engine (MDI 3000) was instrumented for the measurement of the engine performance, emissions, in-cylinder pressure-crank angle history, rate of pressure rise, and other important combustion parameters such as instantaneous heat release rate, cumulative heat release rate, mass fraction burned, etc. A careful analysis of the performance, emissions, combustion, and heat release parameters has been carried out. HC, CO, and smoke emissions for RBO and RBOME blends were lower than mineral diesel while NOx emissions were almost similar and brake specific fuel consumption (BSFC) was slightly higher than mineral diesel. Combustion characteristics were quite similar for the three fuels. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

Improved three-dimensional crowning profiles for dovetail attachments / J. R. Beisheim in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 04 p. Titre : Improved three-dimensional crowning profiles for dovetail attachments Type de document : texte imprimé Auteurs : J. R. Beisheim, Auteur ; G. B. Sinclair, Auteur Année de publication : 2011 Article en page(s) : 04 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Failure  (mechanical)  Fatigue  Finite  element  analysis  Gas  turbines  Mechanical  contact Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Dovetail attachments in gas turbines are subject to fatigue failures. These fatigue failures occur as a result of large fluctuations in hoop stresses near the edges of contact in attachments. The high hoop stresses available for fluctuating are, in turn, the result of high contact stress peaks near the edges of contact. One means of alleviating these stresses is via crowning. Such crowned configurations are inherently three-dimensional and consequently present some challenges to obtaining convergent contact stresses with finite elements. Such challenges are met in the work of Beisheim and Sinclair (2008, “Three-Dimensional Finite Element Analysis of Dovetail Attachments With and Without Crowning,” ASME J. Turbomach., 130, pp. 021012-1–021021-8), and crowning is shown to reduce contact stresses by about 40%. The crowning profile used in that paper is the natural Hertzian profile of a segment of an ellipsoid. This note investigates an alternative profile with a view to increasing the area of contact, and thereby further reducing contact stresses. Converged contact stresses are obtained for both profiles, and demonstrate that the alternative profile can indeed reduce contact stresses by an additional 10%. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...] [article] Improved three-dimensional crowning profiles for dovetail attachments [texte imprimé] / J. R. Beisheim, Auteur ; G. B. Sinclair, Auteur . - 2011 . - 04 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 6 (Juin 2010) . - 04 p. Mots-clés : Failure  (mechanical)  Fatigue  Finite  element  analysis  Gas  turbines  Mechanical  contact Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Dovetail attachments in gas turbines are subject to fatigue failures. These fatigue failures occur as a result of large fluctuations in hoop stresses near the edges of contact in attachments. The high hoop stresses available for fluctuating are, in turn, the result of high contact stress peaks near the edges of contact. One means of alleviating these stresses is via crowning. Such crowned configurations are inherently three-dimensional and consequently present some challenges to obtaining convergent contact stresses with finite elements. Such challenges are met in the work of Beisheim and Sinclair (2008, “Three-Dimensional Finite Element Analysis of Dovetail Attachments With and Without Crowning,” ASME J. Turbomach., 130, pp. 021012-1–021021-8), and crowning is shown to reduce contact stresses by about 40%. The crowning profile used in that paper is the natural Hertzian profile of a segment of an ellipsoid. This note investigates an alternative profile with a view to increasing the area of contact, and thereby further reducing contact stresses. Converged contact stresses are obtained for both profiles, and demonstrate that the alternative profile can indeed reduce contact stresses by an additional 10%. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000006 [...]

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