Abstract The measured synchronous response of rotor components may be analyzed with two objectives. On the one hand, the estimation of the response amplitude is necessary for structural calculations such as the assessment of the low-cycle fatigue safety margin. On the other hand, it is used for system identification purpose with particular interest for damping. Both these tasks can be carried out efficiently and accurately using the time-frequency analysis based on the continuous wavelet transform. A major issue that limits a wide use of this tool is the lack of criteria to guide the analysist to a proper choice of the parameters involved in the wavelet transform. This paper discusses this problem from a theoretical and practical point of view and provides a criterion valid for the analysis of the response during resonance crossings.
{"title":"Analysis of the Synchronous Response of Rotor Components by Wavelet Transform and Wavelet Probing","authors":"Luigi Carassale","doi":"10.1115/1.4063712","DOIUrl":"https://doi.org/10.1115/1.4063712","url":null,"abstract":"Abstract The measured synchronous response of rotor components may be analyzed with two objectives. On the one hand, the estimation of the response amplitude is necessary for structural calculations such as the assessment of the low-cycle fatigue safety margin. On the other hand, it is used for system identification purpose with particular interest for damping. Both these tasks can be carried out efficiently and accurately using the time-frequency analysis based on the continuous wavelet transform. A major issue that limits a wide use of this tool is the lack of criteria to guide the analysist to a proper choice of the parameters involved in the wavelet transform. This paper discusses this problem from a theoretical and practical point of view and provides a criterion valid for the analysis of the response during resonance crossings.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136295263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrew Hayden, John Gillespie, Cole Hefner, Alexandrina Untaroiu, K. Todd Lowe
Abstract In recent years, the StreamVane technology has developed into a mature and streamlined process that can reproduce swirl distortion for ground-test evaluation of fan and compressor performance and durability. A StreamVane device consists of complex turning vanes that accurately output a distorted secondary velocity field at a defined distance downstream. To further advance the applications and conditions in which these devices operate, a research effort was developed and completed to investigate methods to increase critical Mach numbers. The effort was split into three separate stages: 1) Perform high fidelity computational fluid dynamics (CFD) to identify peak Mach number locations within twin and quad swirl vane pack designs; 2) Conduct thorough literature reviews on relevant high throughflow techniques; 3) Design and implement selected techniques to evaluate improvements using the same high-fidelity CFD methods. It was predicted that employing blade lean within high-speed vane junctions increased critical Mach numbers by 6.6%, while blade sweep resulted in a 3.5% increase. The results and conclusions from this effort are presented throughout this paper with a primary focus on comparing Mach numbers and swirl profiles between vane packs with and without high throughflow designs.
{"title":"High Throughflow Streamvane Swirl Distortion Generators: Design and Analysis","authors":"Andrew Hayden, John Gillespie, Cole Hefner, Alexandrina Untaroiu, K. Todd Lowe","doi":"10.1115/1.4063709","DOIUrl":"https://doi.org/10.1115/1.4063709","url":null,"abstract":"Abstract In recent years, the StreamVane technology has developed into a mature and streamlined process that can reproduce swirl distortion for ground-test evaluation of fan and compressor performance and durability. A StreamVane device consists of complex turning vanes that accurately output a distorted secondary velocity field at a defined distance downstream. To further advance the applications and conditions in which these devices operate, a research effort was developed and completed to investigate methods to increase critical Mach numbers. The effort was split into three separate stages: 1) Perform high fidelity computational fluid dynamics (CFD) to identify peak Mach number locations within twin and quad swirl vane pack designs; 2) Conduct thorough literature reviews on relevant high throughflow techniques; 3) Design and implement selected techniques to evaluate improvements using the same high-fidelity CFD methods. It was predicted that employing blade lean within high-speed vane junctions increased critical Mach numbers by 6.6%, while blade sweep resulted in a 3.5% increase. The results and conclusions from this effort are presented throughout this paper with a primary focus on comparing Mach numbers and swirl profiles between vane packs with and without high throughflow designs.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136354184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The flow structures and heat transfer within rotating cavities of aero-engine axial compressors influences the thermal expansion of the rotor discs, and consequently the blade-tip clearances. To investigate the flow field at the bore and lower cavity region, experimental measurements have been acquired in an engine representative test facility. Axial, tangential and radial velocities were measured using a miniature five-hole probe at a range of axial and radial positions. Time-averaged results from 28 tests carried out at non-dimensional parameters comparable to engine conditions: 1.3 × 104 ≤ Rez ≤ 8.2 ×104, 3.0 × 105 ≤ Reθ ≤ 3.2 × 106, 0.11 ≤ Ro ≤ 3.24, 0.14 ≤ βΔT ≤ 0.36 are presented in this paper. The axial and tangential velocity measurements conform to previous work, while the radial velocity component provides quantitative evidence of an asymmetric toroidal vortex in the cavity gap, biased towards the downstream disc. The vortex is characterised by the local vorticity and grows in strength and size as Rossby number increases above Ro = 0.34 to 1.63. The effect of βΔT on the vortex formation is negligible compared to the influence of the tangential Reynolds number as the local circulation is suppressed by the Coriolis forces at high rotational speeds. Both the tangential and radial velocity results suggest that as Ro is increased, the proportion of air that is radially ingested and expelled from a cavity decreases.
{"title":"Experimental Measurements of Flow-Averaged Toroidal Vortices in Buoyancy-Dominated Rotating Cavities","authors":"Emma C. Fox, Mark R. Puttock-Brown","doi":"10.1115/1.4063689","DOIUrl":"https://doi.org/10.1115/1.4063689","url":null,"abstract":"Abstract The flow structures and heat transfer within rotating cavities of aero-engine axial compressors influences the thermal expansion of the rotor discs, and consequently the blade-tip clearances. To investigate the flow field at the bore and lower cavity region, experimental measurements have been acquired in an engine representative test facility. Axial, tangential and radial velocities were measured using a miniature five-hole probe at a range of axial and radial positions. Time-averaged results from 28 tests carried out at non-dimensional parameters comparable to engine conditions: 1.3 × 104 ≤ Rez ≤ 8.2 ×104, 3.0 × 105 ≤ Reθ ≤ 3.2 × 106, 0.11 ≤ Ro ≤ 3.24, 0.14 ≤ βΔT ≤ 0.36 are presented in this paper. The axial and tangential velocity measurements conform to previous work, while the radial velocity component provides quantitative evidence of an asymmetric toroidal vortex in the cavity gap, biased towards the downstream disc. The vortex is characterised by the local vorticity and grows in strength and size as Rossby number increases above Ro = 0.34 to 1.63. The effect of βΔT on the vortex formation is negligible compared to the influence of the tangential Reynolds number as the local circulation is suppressed by the Coriolis forces at high rotational speeds. Both the tangential and radial velocity results suggest that as Ro is increased, the proportion of air that is radially ingested and expelled from a cavity decreases.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135253650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Simon Tartsch, Saskia Flebbe, Joao Germano Marques de Sousa Ponte, Thomas Sattelmayer
Abstract Flashback with subsequent flame anchoring (FA) is an inherent risk of lean premixed gas turbine combustors operated with highly reactive fuel. The present study has been performed to characterize flame stabilization in the premixing zone of a lean premixed swirl stabilized burner and to identify critical combustion characteristics. An optically accessible burner was used for experimental investigations under atmospheric pressure and elevated preheat temperatures. The air mass flow rate, global equivalence ratio and preheat temperature were systematically varied to identify critical operating parameters. Hydrogen-natural gas mixtures with hydrogen mass fractions from 15 to 100 % were studied to evaluate the impact of fuel reactivity. The air-fuel mixture was ignited with a focused single laser pulse to trigger FA in the premixing zone during steady operation. High speed imaging with OH*-chemiluminescence were applied to observe flame characteristics and evaluate flame anchoring propensity. Flame anchoring limits (FAL) are reported in terms of the minimum global equivalence ratio at which the flame was blown out of the premixing zone within a critical time period. A comparison of characteristic time scales at FAL shows that the main impact during flame anchoring is given by the fuel reactivity and to some extent by preheat temperature. A Damköhler criterion is derived from the FAL that allows prediction of FA propensity based on operating conditions and 1-D reacting simulations.
{"title":"Effect of Fuel Reactivity and Operating Conditions On Flame Anchoring in the Premixing Zone of a Swirl Stabilized Gas Turbine Combustor","authors":"Simon Tartsch, Saskia Flebbe, Joao Germano Marques de Sousa Ponte, Thomas Sattelmayer","doi":"10.1115/1.4063688","DOIUrl":"https://doi.org/10.1115/1.4063688","url":null,"abstract":"Abstract Flashback with subsequent flame anchoring (FA) is an inherent risk of lean premixed gas turbine combustors operated with highly reactive fuel. The present study has been performed to characterize flame stabilization in the premixing zone of a lean premixed swirl stabilized burner and to identify critical combustion characteristics. An optically accessible burner was used for experimental investigations under atmospheric pressure and elevated preheat temperatures. The air mass flow rate, global equivalence ratio and preheat temperature were systematically varied to identify critical operating parameters. Hydrogen-natural gas mixtures with hydrogen mass fractions from 15 to 100 % were studied to evaluate the impact of fuel reactivity. The air-fuel mixture was ignited with a focused single laser pulse to trigger FA in the premixing zone during steady operation. High speed imaging with OH*-chemiluminescence were applied to observe flame characteristics and evaluate flame anchoring propensity. Flame anchoring limits (FAL) are reported in terms of the minimum global equivalence ratio at which the flame was blown out of the premixing zone within a critical time period. A comparison of characteristic time scales at FAL shows that the main impact during flame anchoring is given by the fuel reactivity and to some extent by preheat temperature. A Damköhler criterion is derived from the FAL that allows prediction of FA propensity based on operating conditions and 1-D reacting simulations.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135254597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The present study aims to experimentally characterize the performance of a rotating detonation combustion (RDC) system integrated with a pressurized downstream plenum to simulate the high-pressure inlet conditions of power generating gas turbines. A thorough understanding of the operational behavior including wave mode behavior, static pressure profile along the combustor length, and dynamic features of pressure fluctuations is crucial for successful integration of RDC with the turbine. In this study, two RDC configurations are investigated, RDC with a constant area annulus and RDC with a converging nozzle. In both cases, the RDC flow exited into a plenum chamber kept at pressures varying from 155 kPa to 330 kPa. RDC was operated on methane and oxygen-enriched air to represent reactants used in land-based power generation. Experiments were conducted for the two RDCs configurations operated at three reactant mass flow rates (0.23, 0.32, 0.46 kg/s). The RDC performance is characterized by time-averaged static pressures measurements, and wave velocity determined by ionization probes. In addition, dynamic pressure measurements were recorded both inside and near the exit of RDC channel to investigate wave interactions between RDC and downstream plenum. Results show that the RDC with the converging nozzle achieved superior performance while minimizing detrimental interactions with the reflected shock and/or acoustic waves from the downstream plenum.
{"title":"Performance Characteristics of a Rotating Detonation Combustor Exiting Into a Pressurized Pleunum to Simulate Gas Turbine Inlet","authors":"Shaon Talukdar, Dalton Langner, Apurav Gupta, Ajay Agrawal","doi":"10.1115/1.4063710","DOIUrl":"https://doi.org/10.1115/1.4063710","url":null,"abstract":"Abstract The present study aims to experimentally characterize the performance of a rotating detonation combustion (RDC) system integrated with a pressurized downstream plenum to simulate the high-pressure inlet conditions of power generating gas turbines. A thorough understanding of the operational behavior including wave mode behavior, static pressure profile along the combustor length, and dynamic features of pressure fluctuations is crucial for successful integration of RDC with the turbine. In this study, two RDC configurations are investigated, RDC with a constant area annulus and RDC with a converging nozzle. In both cases, the RDC flow exited into a plenum chamber kept at pressures varying from 155 kPa to 330 kPa. RDC was operated on methane and oxygen-enriched air to represent reactants used in land-based power generation. Experiments were conducted for the two RDCs configurations operated at three reactant mass flow rates (0.23, 0.32, 0.46 kg/s). The RDC performance is characterized by time-averaged static pressures measurements, and wave velocity determined by ionization probes. In addition, dynamic pressure measurements were recorded both inside and near the exit of RDC channel to investigate wave interactions between RDC and downstream plenum. Results show that the RDC with the converging nozzle achieved superior performance while minimizing detrimental interactions with the reflected shock and/or acoustic waves from the downstream plenum.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135254789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mahmoud El-Soueidan, Marc Schmelcher, Alexander Görtz, Jannik Häßy, Marius Bröcker
Abstract The Water-Enhanced Turbofan (WET) is a promising future propulsion concept to reduce aero engine emissions. In the WETengine, a heat exchanger uses turbine exhaust heat in order to generate superheated steam out of liquid water. For evaporator design, CFD simulations are necessary since correlation-based predictions have a high uncertainty during preliminary design. A common way of modeling steam loaded flows is the integration of gas models into CFD analysis. However, to the author's knowledge, there is no gas model published that accounts for the exact gas composition of turbine exhaust flows with high steam loads and is commonly used by low- and high-fidelity methods. Therefore, a gas model predicting the thermodynamic behavior of the turbine exhaust flow considering high steam loads is presented and integrated into an existing CFD solver. The approach is able to incorporate the implemented gas model into the CFD simulation by two methods: runtime and offline. The offline method has a computational advantage in iteration time compared to the runtime integration. As demonstration case, a single two dimensional cylinder is considered. A variation of the steam loading of the flow shows a significant effect on local properties and therefore on local and average heat transfer. Increasing the steam loading up to 40 % results in an increase of the average Nusselt number of 17 %.
{"title":"Integration of a Gas Model Into CFD Analysis for the Simulation of Turbine Exhaust Flows with High Steam Loads","authors":"Mahmoud El-Soueidan, Marc Schmelcher, Alexander Görtz, Jannik Häßy, Marius Bröcker","doi":"10.1115/1.4063687","DOIUrl":"https://doi.org/10.1115/1.4063687","url":null,"abstract":"Abstract The Water-Enhanced Turbofan (WET) is a promising future propulsion concept to reduce aero engine emissions. In the WETengine, a heat exchanger uses turbine exhaust heat in order to generate superheated steam out of liquid water. For evaporator design, CFD simulations are necessary since correlation-based predictions have a high uncertainty during preliminary design. A common way of modeling steam loaded flows is the integration of gas models into CFD analysis. However, to the author's knowledge, there is no gas model published that accounts for the exact gas composition of turbine exhaust flows with high steam loads and is commonly used by low- and high-fidelity methods. Therefore, a gas model predicting the thermodynamic behavior of the turbine exhaust flow considering high steam loads is presented and integrated into an existing CFD solver. The approach is able to incorporate the implemented gas model into the CFD simulation by two methods: runtime and offline. The offline method has a computational advantage in iteration time compared to the runtime integration. As demonstration case, a single two dimensional cylinder is considered. A variation of the steam loading of the flow shows a significant effect on local properties and therefore on local and average heat transfer. Increasing the steam loading up to 40 % results in an increase of the average Nusselt number of 17 %.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135254601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jan Paul Beuth, Johann Moritz Reumschüssel, Jakob G.R. von Saldern, Dominik Wassmer, Bernhard Cosic, Christian Oliver Paschereit, Kilian Oberleithner
Abstract In this study, the acoustics and flame dynamics of a prototype multi jet burner with 19 individual mixing tubes for operation with pure hydrogen and pure natural gas are experimentally investigated. The burner transfer matrix of the jet burner is determined from experimental data and acoustic network modeling, showing very good agreement. A comparison of the flame dynamics of the two fuels considering mass flow and equivalence ratio variation reveals that the flame transfer functions (FTFs) are dominated by a convective mechanism originating from the upstream end of the mixing tubes where the fuel is injected. Consequently, these are most likely fluctuations in the equivalence ratio that feature two characteristic time scales: the convection time in the mixing tubes and along the flame. The overall qualitative shape of the FTFs for hydrogen and natural gas at equal thermal power is found to be similar, with the dynamics of the natural gas flames being more responsive to acoustic excitation. Distinctly less pronounced phase decays are observed for hydrogen compared to natural gas operation. Moreover, the FTFs for H2 are found to change only slightly across the considered range of equivalence ratios. At the same time we observe only small changes in the corresponding static flame shapes. These observation are consistent with the hypothesis of a dominant convective mechanism. In conclusion, the study provides valuable information on the acoustics and flame dynamics of multi jet burners for flexible fuel operation.
{"title":"Thermoacoustic Characterization of a Premixed Multi Jet Burner for Hydrogen and Natural Gas Combustion","authors":"Jan Paul Beuth, Johann Moritz Reumschüssel, Jakob G.R. von Saldern, Dominik Wassmer, Bernhard Cosic, Christian Oliver Paschereit, Kilian Oberleithner","doi":"10.1115/1.4063692","DOIUrl":"https://doi.org/10.1115/1.4063692","url":null,"abstract":"Abstract In this study, the acoustics and flame dynamics of a prototype multi jet burner with 19 individual mixing tubes for operation with pure hydrogen and pure natural gas are experimentally investigated. The burner transfer matrix of the jet burner is determined from experimental data and acoustic network modeling, showing very good agreement. A comparison of the flame dynamics of the two fuels considering mass flow and equivalence ratio variation reveals that the flame transfer functions (FTFs) are dominated by a convective mechanism originating from the upstream end of the mixing tubes where the fuel is injected. Consequently, these are most likely fluctuations in the equivalence ratio that feature two characteristic time scales: the convection time in the mixing tubes and along the flame. The overall qualitative shape of the FTFs for hydrogen and natural gas at equal thermal power is found to be similar, with the dynamics of the natural gas flames being more responsive to acoustic excitation. Distinctly less pronounced phase decays are observed for hydrogen compared to natural gas operation. Moreover, the FTFs for H2 are found to change only slightly across the considered range of equivalence ratios. At the same time we observe only small changes in the corresponding static flame shapes. These observation are consistent with the hypothesis of a dominant convective mechanism. In conclusion, the study provides valuable information on the acoustics and flame dynamics of multi jet burners for flexible fuel operation.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antoine Durocher, Luming Fan, Benjamin Francolini, Marc Furi, Gilles Bourque, Julien Sirois, David May, Jeffrey M. Bergthorson, Sean Yun, Patrizio Vena
Abstract As the energy landscape transitions to low/zero-carbon fuels, gas turbine manufacturers are targeting fuel flexible operation with natural gas, syngas, and hydrogen-enriched mixtures. Having a single geometry that can support different fuel blends can accelerate the transition to cleaner energy generation. Toward this goal, micromix combustion technology has received significant interest, and when coupled with additive manufacturing, novel injector geometries with unique configurations may be capable of stabilizing premixed, partially-premixed, and diffusion flames using fuel mixtures ranging from pure methane to pure hydrogen. In this work, a preliminary investigation of this micromix concept is performed in the Atmospheric Combustion Rig at the National Research Council Canada. Flame stability maps are obtained for fuel lean mixtures of H2/CH4 ranging from 0/100, 70/30, 90/10, to 100/0%, by volume. Multiple flame shapes are observed depending on the fuel mixture and combustion mode selected. PIV, OH, and acetone planar laser-induced fluorescence (PLIF), and acoustic measurements provide insights into the combustion process of these novel burners. The quality of the fuel-air mixing is assessed using acetone as a tracer for the fuel, while simultaneous OH-PLIF measurements provide an indication of the post-flame regions in the flow. Acoustic measurements complete the current dataset and provide combustion dynamics maps and the dominant acoustic frequencies. The preliminary characterization of this AM micromix nozzle shows promising fuel flexibility with wide stability margins and low combustion dynamics for this single nozzle burner.
{"title":"Characterization of a Novel Am Micromix Nozzle Burning Methane to Hydrogen","authors":"Antoine Durocher, Luming Fan, Benjamin Francolini, Marc Furi, Gilles Bourque, Julien Sirois, David May, Jeffrey M. Bergthorson, Sean Yun, Patrizio Vena","doi":"10.1115/1.4063690","DOIUrl":"https://doi.org/10.1115/1.4063690","url":null,"abstract":"Abstract As the energy landscape transitions to low/zero-carbon fuels, gas turbine manufacturers are targeting fuel flexible operation with natural gas, syngas, and hydrogen-enriched mixtures. Having a single geometry that can support different fuel blends can accelerate the transition to cleaner energy generation. Toward this goal, micromix combustion technology has received significant interest, and when coupled with additive manufacturing, novel injector geometries with unique configurations may be capable of stabilizing premixed, partially-premixed, and diffusion flames using fuel mixtures ranging from pure methane to pure hydrogen. In this work, a preliminary investigation of this micromix concept is performed in the Atmospheric Combustion Rig at the National Research Council Canada. Flame stability maps are obtained for fuel lean mixtures of H2/CH4 ranging from 0/100, 70/30, 90/10, to 100/0%, by volume. Multiple flame shapes are observed depending on the fuel mixture and combustion mode selected. PIV, OH, and acetone planar laser-induced fluorescence (PLIF), and acoustic measurements provide insights into the combustion process of these novel burners. The quality of the fuel-air mixing is assessed using acetone as a tracer for the fuel, while simultaneous OH-PLIF measurements provide an indication of the post-flame regions in the flow. Acoustic measurements complete the current dataset and provide combustion dynamics maps and the dominant acoustic frequencies. The preliminary characterization of this AM micromix nozzle shows promising fuel flexibility with wide stability margins and low combustion dynamics for this single nozzle burner.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Valerie Hernley, Jeong-Seek Kang, Matthew Montgomery, Jae Hoon Chung, Aleksander Jemcov, Scott C. Morris
Abstract Non-synchronous vibration (NSV) in axial compressors can be caused either by 1) unsteady aerodynamic forces that are not related to motion of the blades or 2) motion-dependent aerodynamic forcing (e.g., flutter). Aerodynamic forcing mechanisms can be challenging to identify in experimental observations of NSV because the temporal vibration characteristics for both forcing mechanisms can appear similar. This work proposes a method for distinguishing between the two mechanisms using spectral characteristics. The method provides an interpretation of experimental data explicitly consistent with the analytical models used to differentiate between forced response and flutter. Two cases of NSV were observed in a 1.5-stage axial compressor at near stall conditions. The circumferential wavenumber-dependent unsteady pressure spectra and non-intrusive stress measurement system (NSMS) spectra were observed to have distinct characteristics for the two NSV cases. Based on these distinct spectral characteristics, the first case was identified as blade-row aerodynamic forcing, while the second was identified as motion dependent (flutter). Numerical simulations confirmed low aerodynamic damping at the conditions where flutter was observed.
{"title":"Identification of Compressor Vibration Aerodynamic Forcing Mechanisms by Spectral Characteristics","authors":"Valerie Hernley, Jeong-Seek Kang, Matthew Montgomery, Jae Hoon Chung, Aleksander Jemcov, Scott C. Morris","doi":"10.1115/1.4063685","DOIUrl":"https://doi.org/10.1115/1.4063685","url":null,"abstract":"Abstract Non-synchronous vibration (NSV) in axial compressors can be caused either by 1) unsteady aerodynamic forces that are not related to motion of the blades or 2) motion-dependent aerodynamic forcing (e.g., flutter). Aerodynamic forcing mechanisms can be challenging to identify in experimental observations of NSV because the temporal vibration characteristics for both forcing mechanisms can appear similar. This work proposes a method for distinguishing between the two mechanisms using spectral characteristics. The method provides an interpretation of experimental data explicitly consistent with the analytical models used to differentiate between forced response and flutter. Two cases of NSV were observed in a 1.5-stage axial compressor at near stall conditions. The circumferential wavenumber-dependent unsteady pressure spectra and non-intrusive stress measurement system (NSMS) spectra were observed to have distinct characteristics for the two NSV cases. Based on these distinct spectral characteristics, the first case was identified as blade-row aerodynamic forcing, while the second was identified as motion dependent (flutter). Numerical simulations confirmed low aerodynamic damping at the conditions where flutter was observed.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
John Richardson, Ryan Wardell, Erik Fernandez, Jayanta Kapat
Abstract This study experimentally and computationally investigates the heat transfer capability of supercritical carbon dioxide (sCO2) single jet impingement. The evaluated jet Reynolds number range is between 80000 and 600000, with a non-dimensional jet-to-target surface spacing of 2.8. CO2 impinging jet stagnation conditions were maintained at approximately 200 bar and 400°C for most experiments. The goal is to understand how changes in the aforementioned parameters influence heat transfer between the working fluid and the heated surface. Additionally, due to the elevated Reynolds numbers and difference in thermodynamic properties between air and CO2, air derived impingement correlations may not be appropriate for CO2 impingement; these correlations are evaluated against experimental sCO2 data. At the time of this study, no sCO2 impingement data was available relevant to sCO2 power cycles. The target surface is a 1.5- inch diameter copper block centered on the 3 mm orifice. At the bottom of the copper block, a mica heater provides a uniform heat flux. Thermocouples embedded in the copper block are used to determine the surface temperature. The Nusselt numbers from experimental sCO2 data and air derived area averaged correlations are compared. The comparisons showed that air correlations drastically underpredict the heat transfer when sCO2 is used as the working fluid. A modified sCO2 correlation using experimental data at discussed conditions, is derived based on an existing air correlation. A CFD study is also performed to further investigate sCO2 heat transfer characteristics, and assess the applicability to this problem type.
{"title":"Experimental and Computational Heat Transfer Study of SCO2 Single-Jet Impingement","authors":"John Richardson, Ryan Wardell, Erik Fernandez, Jayanta Kapat","doi":"10.1115/1.4063691","DOIUrl":"https://doi.org/10.1115/1.4063691","url":null,"abstract":"Abstract This study experimentally and computationally investigates the heat transfer capability of supercritical carbon dioxide (sCO2) single jet impingement. The evaluated jet Reynolds number range is between 80000 and 600000, with a non-dimensional jet-to-target surface spacing of 2.8. CO2 impinging jet stagnation conditions were maintained at approximately 200 bar and 400°C for most experiments. The goal is to understand how changes in the aforementioned parameters influence heat transfer between the working fluid and the heated surface. Additionally, due to the elevated Reynolds numbers and difference in thermodynamic properties between air and CO2, air derived impingement correlations may not be appropriate for CO2 impingement; these correlations are evaluated against experimental sCO2 data. At the time of this study, no sCO2 impingement data was available relevant to sCO2 power cycles. The target surface is a 1.5- inch diameter copper block centered on the 3 mm orifice. At the bottom of the copper block, a mica heater provides a uniform heat flux. Thermocouples embedded in the copper block are used to determine the surface temperature. The Nusselt numbers from experimental sCO2 data and air derived area averaged correlations are compared. The comparisons showed that air correlations drastically underpredict the heat transfer when sCO2 is used as the working fluid. A modified sCO2 correlation using experimental data at discussed conditions, is derived based on an existing air correlation. A CFD study is also performed to further investigate sCO2 heat transfer characteristics, and assess the applicability to this problem type.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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