Roda Bounaceur, Romain Heymes, Pierre Alexandre Glaude, Baptiste Sirjean, René Fournet, Pierre Montagne, A Auvray, E Impellizzeri, Pierre Biehler, Alexandre Picard, B Prieur-Garrouste, Michel Moliere
Abstract Hydrogen-compatible gas turbines are one way to decarbonize electricity production. Burning and handling hydrogen is not trivial because of its tendency to detonate. Mandatory safety parameters can be estimated thanks to predictive detailed kinetic models, but with significant calculation times that limit coupling with fluid mechanic codes. An auto-ignition prediction tool was developed based on an artificial intelligence (AI) model for fast computations and an implementation into an explosion model. A dataset of ignition delay times was generated automatically using a recent detailed kinetic modelselected from the literature. Generated data covers a wide operating range and different compositions of fuels. Clustering problems in sample points were avoided by a quasi-random Sobol sequence, which covers uniformly the entire input parameter space. The different algorithms were trained, cross-validated and tested using a database of more than 70'000 ignitions cases of Natural Gas/Hydrogen blends calculated with the full kinetic model by using a common split of 70/30 for training, testing. The AI model shows a high degree of robustness. For both the training and testing datasets, the average value of the correlation coefficient was above 99.91%, the Mean Absolute Error (MAE) and the Mean Square Error (MSE) around 0.03 and lower than 0.04 respectively. Tests showed the robustness of the AI model outside the ranges of pressure, temperature, and equivalence ratio of the data set. A deterioration is however observed with increasing amounts of large alkanes in the natural gas.
{"title":"Development of an Artificial Intelligence Model to Predict Combustion Properties, with a Focus On Auto-ignition Delay","authors":"Roda Bounaceur, Romain Heymes, Pierre Alexandre Glaude, Baptiste Sirjean, René Fournet, Pierre Montagne, A Auvray, E Impellizzeri, Pierre Biehler, Alexandre Picard, B Prieur-Garrouste, Michel Moliere","doi":"10.1115/1.4063774","DOIUrl":"https://doi.org/10.1115/1.4063774","url":null,"abstract":"Abstract Hydrogen-compatible gas turbines are one way to decarbonize electricity production. Burning and handling hydrogen is not trivial because of its tendency to detonate. Mandatory safety parameters can be estimated thanks to predictive detailed kinetic models, but with significant calculation times that limit coupling with fluid mechanic codes. An auto-ignition prediction tool was developed based on an artificial intelligence (AI) model for fast computations and an implementation into an explosion model. A dataset of ignition delay times was generated automatically using a recent detailed kinetic modelselected from the literature. Generated data covers a wide operating range and different compositions of fuels. Clustering problems in sample points were avoided by a quasi-random Sobol sequence, which covers uniformly the entire input parameter space. The different algorithms were trained, cross-validated and tested using a database of more than 70'000 ignitions cases of Natural Gas/Hydrogen blends calculated with the full kinetic model by using a common split of 70/30 for training, testing. The AI model shows a high degree of robustness. For both the training and testing datasets, the average value of the correlation coefficient was above 99.91%, the Mean Absolute Error (MAE) and the Mean Square Error (MSE) around 0.03 and lower than 0.04 respectively. Tests showed the robustness of the AI model outside the ranges of pressure, temperature, and equivalence ratio of the data set. A deterioration is however observed with increasing amounts of large alkanes in the natural gas.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135993998","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}
Saeed Izadi, Jan Zanger, Martina Baggio, Hannah Seliger-Ost, Peter Kutne, Manfred Aigner
Abstract The effect of superheated liquid fuel injection on the performance and emissions of a single nozzle combustor was investigated. Combustion of the lean premixed flames was achieved using a combination of jet and swirl as a stabilization method. In a non-reactive setup, the optimum transition temperature of Jet A-1 fuel from liquid to superheated vaporized state was analyzed. In a subsequent reactive setup, a series of tests were conducted with the liquid fuel at low and elevated temperatures. The experiments were conducted at ambient pressure and various air and fuel preheat temperatures, axial swirlers, thermal powers, adiabatic flame temperatures, and flame tube diameters. Concentrations of nitric oxide (NOx) and carbon monoxide (CO) in the flue gas were measured. The results showed that the adiabatic flame temperature caused the most significant change in combustion emissions and the position and shape of the reaction zone, while the superheated fuel injection had only a minor effect because the liquid fuel droplets were largely vaporized before entering the reaction zone through the integration of a swirler and a prefilmer. The use of the axial swirler and prefilmer allowed the combustor to operate in both spray and fully vaporized fuel conditions. As a result, very low emission concentrations of NOx (~5 ppm) and CO (~6 ppm) were achieved. The median flame length and height above the burner of the characterized flames showed competitive values of 32 and 50 mm, respectively. Lean blowout limits of less than 1500 K were achieved.
{"title":"Experimental Investigation of the Effect of Superheated Liquid Fuel Injection On the Combustion Characteristics of Lean Premixed Flames","authors":"Saeed Izadi, Jan Zanger, Martina Baggio, Hannah Seliger-Ost, Peter Kutne, Manfred Aigner","doi":"10.1115/1.4063772","DOIUrl":"https://doi.org/10.1115/1.4063772","url":null,"abstract":"Abstract The effect of superheated liquid fuel injection on the performance and emissions of a single nozzle combustor was investigated. Combustion of the lean premixed flames was achieved using a combination of jet and swirl as a stabilization method. In a non-reactive setup, the optimum transition temperature of Jet A-1 fuel from liquid to superheated vaporized state was analyzed. In a subsequent reactive setup, a series of tests were conducted with the liquid fuel at low and elevated temperatures. The experiments were conducted at ambient pressure and various air and fuel preheat temperatures, axial swirlers, thermal powers, adiabatic flame temperatures, and flame tube diameters. Concentrations of nitric oxide (NOx) and carbon monoxide (CO) in the flue gas were measured. The results showed that the adiabatic flame temperature caused the most significant change in combustion emissions and the position and shape of the reaction zone, while the superheated fuel injection had only a minor effect because the liquid fuel droplets were largely vaporized before entering the reaction zone through the integration of a swirler and a prefilmer. The use of the axial swirler and prefilmer allowed the combustor to operate in both spray and fully vaporized fuel conditions. As a result, very low emission concentrations of NOx (~5 ppm) and CO (~6 ppm) were achieved. The median flame length and height above the burner of the characterized flames showed competitive values of 32 and 50 mm, respectively. Lean blowout limits of less than 1500 K were achieved.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135994827","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}
Michael Pierro, Justin Urso, Ramees K. Rahman, Christopher W Dennis, Marley Albright, Jonathan McGaunn, Cory Kinney, Subith Vasu
Abstract Ignition delay times from undiluted mixtures of natural gas (NG)/H2/Air and NG/NH3/Air were measured using a high-pressure shock tube at the University of Central Florida. The combustion temperatures were experimentally tested between 1000-1500 K near a constant pressure of 25 bar. As mentioned, mixtures were kept undiluted to replicate the same chemistry pathways seen in gas turbine combustion chambers. Recorded combustion pressures exceeded 200 bar due to the large energy release, hence why these were performed at the high-pressure shock tube facility. The data is compared to the predictions of the NUIGMech 1.1 mechanism for chemical kinetic model validation and refinement. An exceptional agreement was shown for stoichiometric conditions in all cases but strayed at lean and rich equivalence ratios, especially in the lower temperature regime of H2 addition and all temperature ranges of the baseline NG mixture. Hydrogen addition also decreased ignition delay times by nearly 90%, while NH3 fuel addition made no noticeable difference in ignition time. NG/NH3 exhibited similar chemistry to pure NG under the same conditions, which is shown in a sensitivity analysis. The reaction CH3 + O2 = CH3O + O is identified and suggested as a possible modification target to improve model performance. Increasing the robustness of chemical kinetic models via experimental validation will directly aid in designing next-generation combustion chambers for use in gas turbines, which in turn will greatly lower global emissions and reduce greenhouse effects.
{"title":"Hydrogen and Ammonia Blending with Natural Gas: Ignition Delay Times and Chemical Kinetic Model Validation At Gas Turbine Relevant Conditions","authors":"Michael Pierro, Justin Urso, Ramees K. Rahman, Christopher W Dennis, Marley Albright, Jonathan McGaunn, Cory Kinney, Subith Vasu","doi":"10.1115/1.4063789","DOIUrl":"https://doi.org/10.1115/1.4063789","url":null,"abstract":"Abstract Ignition delay times from undiluted mixtures of natural gas (NG)/H2/Air and NG/NH3/Air were measured using a high-pressure shock tube at the University of Central Florida. The combustion temperatures were experimentally tested between 1000-1500 K near a constant pressure of 25 bar. As mentioned, mixtures were kept undiluted to replicate the same chemistry pathways seen in gas turbine combustion chambers. Recorded combustion pressures exceeded 200 bar due to the large energy release, hence why these were performed at the high-pressure shock tube facility. The data is compared to the predictions of the NUIGMech 1.1 mechanism for chemical kinetic model validation and refinement. An exceptional agreement was shown for stoichiometric conditions in all cases but strayed at lean and rich equivalence ratios, especially in the lower temperature regime of H2 addition and all temperature ranges of the baseline NG mixture. Hydrogen addition also decreased ignition delay times by nearly 90%, while NH3 fuel addition made no noticeable difference in ignition time. NG/NH3 exhibited similar chemistry to pure NG under the same conditions, which is shown in a sensitivity analysis. The reaction CH3 + O2 = CH3O + O is identified and suggested as a possible modification target to improve model performance. Increasing the robustness of chemical kinetic models via experimental validation will directly aid in designing next-generation combustion chambers for use in gas turbines, which in turn will greatly lower global emissions and reduce greenhouse effects.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"183 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944503","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 This paper discusses a study performed by SoftInWay as part of a Phase II SBIR project funded by NASA. In contrast with the Phase I project (published in paper GTP-22-1328) where three discrete compressors were considered, the Phase II study was focused on addressing the problem of axial compressor long development time and cost with the use of AI models capable of predicting the geometry and performance of various multi-stage axial compressors with multiple variable vanes. The applicability of the AI models to various compressors enables the opportunity to avoid iterations between engine cycle analysis and compressor design. In this paper, automated compressor design and performance generation workflows are described. The approach for autonomous selection of the architectures and hyperparameters of Machine Learning (ML) models is explained. The uncertainty quantification techniques are considered. The developed ML-powered methods for compressor geometry prediction are discussed. The ML models' accuracy values and representations of typical geometry and performance predictions are given. The utilization of the ML models in engine cycle analysis is discussed.
{"title":"Axial Compressor Map Generation Leveraging Autonomous Self-Training Artificial Intelligence. Phase 2","authors":"Maksym Burlaka, Sascha Podlech, Leonid Moroz","doi":"10.1115/1.4063779","DOIUrl":"https://doi.org/10.1115/1.4063779","url":null,"abstract":"Abstract This paper discusses a study performed by SoftInWay as part of a Phase II SBIR project funded by NASA. In contrast with the Phase I project (published in paper GTP-22-1328) where three discrete compressors were considered, the Phase II study was focused on addressing the problem of axial compressor long development time and cost with the use of AI models capable of predicting the geometry and performance of various multi-stage axial compressors with multiple variable vanes. The applicability of the AI models to various compressors enables the opportunity to avoid iterations between engine cycle analysis and compressor design. In this paper, automated compressor design and performance generation workflows are described. The approach for autonomous selection of the architectures and hyperparameters of Machine Learning (ML) models is explained. The uncertainty quantification techniques are considered. The developed ML-powered methods for compressor geometry prediction are discussed. The ML models' accuracy values and representations of typical geometry and performance predictions are given. The utilization of the ML models in engine cycle analysis is discussed.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136115991","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}
Francesco Di Sabatino, Kevin Wan, Julien Manin, Tyler Capil, Yolanda Hicks, Alex Gander, Cyril Crua
Abstract With aviation's dependence on the high volumetric energy density offered by liquid fuels, Sustainable Aviation Fuels (SAFs) could offer the fastest path towards the decarbonization of aircrafts. However, the chemical properties of SAFs present new challenges, and research is needed to better understand their injection, combustion and emission processes. One of these processes in particular is about droplet evaporation at relevant pressures and temperatures, and this represents the focus of the present manuscript. To address this gap we characterized the evaporation and mixing of spray droplets at conditions relevant to modern and next generation aero-engine combustors. We tested three fuels from the National Jet Fuel Combustion Program, namely an average Jet A fuel (A-2), an alcohol-to-jet fuel (C-1), and a blend made of 40 % C-1 and 60 % iso-paraffins (C-4). We also tested a single component normal alkane: n-dodecane, as well as an advanced bio-derived cyclo-alkane fuel: bicyclohexyl. The time evolution of fuel droplets was monitored using high-speed long-distance microscopy. The collected images were processed using a purposely-developed and trained machine learning (ML) algorithm to detect and characterize the droplets' evaporation regime. The results revealed different evaporation regimes, such as classical and diffusive. In agreement with previous studies, evaporation regimes appear to be controlled by ambient pressure, temperature, and fuel type. The measurements demonstrate that diffusive evaporation is relevant at high-pressure conditions, such as take-off combustor pressures for modern commercial aircraft engines.
{"title":"The Role of Diffusive Mixing in Current and Future Aviation Fuels at Relevant Operating Conditions","authors":"Francesco Di Sabatino, Kevin Wan, Julien Manin, Tyler Capil, Yolanda Hicks, Alex Gander, Cyril Crua","doi":"10.1115/1.4063773","DOIUrl":"https://doi.org/10.1115/1.4063773","url":null,"abstract":"Abstract With aviation's dependence on the high volumetric energy density offered by liquid fuels, Sustainable Aviation Fuels (SAFs) could offer the fastest path towards the decarbonization of aircrafts. However, the chemical properties of SAFs present new challenges, and research is needed to better understand their injection, combustion and emission processes. One of these processes in particular is about droplet evaporation at relevant pressures and temperatures, and this represents the focus of the present manuscript. To address this gap we characterized the evaporation and mixing of spray droplets at conditions relevant to modern and next generation aero-engine combustors. We tested three fuels from the National Jet Fuel Combustion Program, namely an average Jet A fuel (A-2), an alcohol-to-jet fuel (C-1), and a blend made of 40 % C-1 and 60 % iso-paraffins (C-4). We also tested a single component normal alkane: n-dodecane, as well as an advanced bio-derived cyclo-alkane fuel: bicyclohexyl. The time evolution of fuel droplets was monitored using high-speed long-distance microscopy. The collected images were processed using a purposely-developed and trained machine learning (ML) algorithm to detect and characterize the droplets' evaporation regime. The results revealed different evaporation regimes, such as classical and diffusive. In agreement with previous studies, evaporation regimes appear to be controlled by ambient pressure, temperature, and fuel type. The measurements demonstrate that diffusive evaporation is relevant at high-pressure conditions, such as take-off combustor pressures for modern commercial aircraft engines.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112531","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}
Joshua Bowen, Josh Bird, Harry Cross, Matthew Jenkins, Aaron Bowsher, Peter Crudgington, Carl M. Sangan, James Scobie
Abstract Brush seals consist of a static ring of densely packed, flexible, fine wire bristles that provide resistance to the flow. Pressure relieving brush seals can be employed to overcome issues such as hysteresis that affect seal durability by reducing friction between the bristle pack and back plate surface. The impact of such designs on the fluid dynamic behaviour of brush seals was studied following a concomitant methodology that exploited the benefits of both engine representative and large-scale testing facilities. Leakage data were fitted using a porous medium model found in the literature to quantify viscous and inertial resistance coefficients. Shaft rotation was shown to cause a reduction in seal leakage and an increase in static pressure on the back plate surface. The pressure relieving back plates also resulted in increased static pressures at this location, causing a reduction in flow resistance that increased leakage through the porous bristle pack. Interrogation of the large-scale inter-bristle pressure field for the two back plate designs revealed the distributions of axial pressure diverged towards the rear of the bristle pack. The detail gathered using the large-scale study has been shown to be representative, hence the insight is generically applicable to brush seals.
{"title":"Fluid Dynamic Behaviour of Conventional and Pressure Relieving Brush Seals","authors":"Joshua Bowen, Josh Bird, Harry Cross, Matthew Jenkins, Aaron Bowsher, Peter Crudgington, Carl M. Sangan, James Scobie","doi":"10.1115/1.4063775","DOIUrl":"https://doi.org/10.1115/1.4063775","url":null,"abstract":"Abstract Brush seals consist of a static ring of densely packed, flexible, fine wire bristles that provide resistance to the flow. Pressure relieving brush seals can be employed to overcome issues such as hysteresis that affect seal durability by reducing friction between the bristle pack and back plate surface. The impact of such designs on the fluid dynamic behaviour of brush seals was studied following a concomitant methodology that exploited the benefits of both engine representative and large-scale testing facilities. Leakage data were fitted using a porous medium model found in the literature to quantify viscous and inertial resistance coefficients. Shaft rotation was shown to cause a reduction in seal leakage and an increase in static pressure on the back plate surface. The pressure relieving back plates also resulted in increased static pressures at this location, causing a reduction in flow resistance that increased leakage through the porous bristle pack. Interrogation of the large-scale inter-bristle pressure field for the two back plate designs revealed the distributions of axial pressure diverged towards the rear of the bristle pack. The detail gathered using the large-scale study has been shown to be representative, hence the insight is generically applicable to brush seals.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"227 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112229","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}
Simeon Dybe, Muhammad Yasir, Felix Güthe, Reddy Alemela, Michael Bartlett, Bruno Schuermans, Christian Oliver Paschereit
Abstract To fight global warming the European Union formulated the objective of completely decarbonising the energy sector, stimulating the advent of unconventional fuels and the adaption of the corresponding energy infrastructure. The decarbonisation strategy identified hydrogen to play a key role as an energy storage medium, making systems capable of pure hydrogen operation essential. This requirement can be fulfilled with humid power cycles which offer additional advantages such as highly efficient and fuel-flexible operation with low emissions. As an integral part of such a cycle, a humid combustion systemwas presented previously showing promising results with respect to complete combustion with low emissions for a variety of fuels. The current work introduces an upgraded version of that combustion system. The new Double Swirler system is capable of stable and safe combustion of low calorific value bio-syngas surrogate, hydrogen, and natural gas, from dry to steam-rich conditions within the required pressure drops. The inclusion of dry operation of the system can benefit the start-up procedure of the humid cycle. The combustor's fuel switching performance is demonstrated by a fast fuel switch at full load from pure hydrogen to pure natural gas and vice versa, while maintaining a stable performance with low NOx-emissions at otherwise constant operation parameters.
{"title":"On the Demonstration of a Humid Combustion System Performing Flexible Fuel-Switch From Pure Hydrogen to Natural Gas with Ultra-Low Nox Emissions","authors":"Simeon Dybe, Muhammad Yasir, Felix Güthe, Reddy Alemela, Michael Bartlett, Bruno Schuermans, Christian Oliver Paschereit","doi":"10.1115/1.4063767","DOIUrl":"https://doi.org/10.1115/1.4063767","url":null,"abstract":"Abstract To fight global warming the European Union formulated the objective of completely decarbonising the energy sector, stimulating the advent of unconventional fuels and the adaption of the corresponding energy infrastructure. The decarbonisation strategy identified hydrogen to play a key role as an energy storage medium, making systems capable of pure hydrogen operation essential. This requirement can be fulfilled with humid power cycles which offer additional advantages such as highly efficient and fuel-flexible operation with low emissions. As an integral part of such a cycle, a humid combustion systemwas presented previously showing promising results with respect to complete combustion with low emissions for a variety of fuels. The current work introduces an upgraded version of that combustion system. The new Double Swirler system is capable of stable and safe combustion of low calorific value bio-syngas surrogate, hydrogen, and natural gas, from dry to steam-rich conditions within the required pressure drops. The inclusion of dry operation of the system can benefit the start-up procedure of the humid cycle. The combustor's fuel switching performance is demonstrated by a fast fuel switch at full load from pure hydrogen to pure natural gas and vice versa, while maintaining a stable performance with low NOx-emissions at otherwise constant operation parameters.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"221 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112236","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}
Stefan Schwarz, Johannes Reil, Johann Gross, Andreas Hartung, David Rittinger, Malte Krack
Abstract In this paper, an experimental test rig for friction saturated limit cycle oscillations is proposed to provide a validation basis for corresponding numerical methods. Having in mind the application of turbine blades, an instrumented beam-like structure equipped with an adjustable velocity feedback loop and dry frictional contacts is designed and investigated. After dimensioning the test rig by means of a simplified one dimensional beam model and time domain simulations, the specific requirements of limit cycle oscillations for the design of the frictional contact, the velocity feedback loop and the excitation system are discussed and possible solutions are presented. Also appropriate measuring principles and evaluation techniques are assessed. After commissioning of the test rig, the influence of the negative damping and the normal contact force on the limit cycle oscillations is measured and the practical stability is investigated. The test rig shows linear dynamics for sticking contact and highly repeatable limit cycles. The measured results are discussed regarding the consistency with theory and compared to the predictions of a three dimensional reduced order model solved in frequency domain by the harmonic balance solver OrAgL. It is demonstrated that the numerical modeling strategy is able to accurately reproduce the measured limit cycle oscillations, which stabilized for different contact normal forces and self-excitation levels.
{"title":"Friction Saturated Limit Cycle Oscillations - Test Rig Design and Validation of Numerical Prediction Methods","authors":"Stefan Schwarz, Johannes Reil, Johann Gross, Andreas Hartung, David Rittinger, Malte Krack","doi":"10.1115/1.4063769","DOIUrl":"https://doi.org/10.1115/1.4063769","url":null,"abstract":"Abstract In this paper, an experimental test rig for friction saturated limit cycle oscillations is proposed to provide a validation basis for corresponding numerical methods. Having in mind the application of turbine blades, an instrumented beam-like structure equipped with an adjustable velocity feedback loop and dry frictional contacts is designed and investigated. After dimensioning the test rig by means of a simplified one dimensional beam model and time domain simulations, the specific requirements of limit cycle oscillations for the design of the frictional contact, the velocity feedback loop and the excitation system are discussed and possible solutions are presented. Also appropriate measuring principles and evaluation techniques are assessed. After commissioning of the test rig, the influence of the negative damping and the normal contact force on the limit cycle oscillations is measured and the practical stability is investigated. The test rig shows linear dynamics for sticking contact and highly repeatable limit cycles. The measured results are discussed regarding the consistency with theory and compared to the predictions of a three dimensional reduced order model solved in frequency domain by the harmonic balance solver OrAgL. It is demonstrated that the numerical modeling strategy is able to accurately reproduce the measured limit cycle oscillations, which stabilized for different contact normal forces and self-excitation levels.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136116765","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}
Tony John, Nicholas Magina, Fei Han, Jan Kaufmann, Manuel Vogel, Thomas Sattelmayer
Abstract This paper presents an analysis of the unsteady heat release rate response of industrially relevant axisymmetric premixed flames to harmonic velocity perturbations. The heat release rate response, quantified using the Flame Transfer Function (FTF) definition, is measured from an acoustically forced swirl burner under perfectly premixed conditions. To understand the features of the measured FTF, a physics based analytical model is developed in this study. To describe the heat release rate dynamics, a model for the flame spatiotemporal response is derived in the linear limit using the G-equation formulation. Inputs to the flame response model are selected to be consistent with values observed in the corresponding industrial burner, based on experimental and numerical studies. The relative contributions of acoustic and convecting vortical disturbances on specific features of the FTF are explored in this study. The results highlight the importance of capturing the appropriate disturbance velocity field as an input to the flame response model for accurate FTF predictions.
{"title":"Modeling Flame Transfer Functions of an Industrial Premixed Burner","authors":"Tony John, Nicholas Magina, Fei Han, Jan Kaufmann, Manuel Vogel, Thomas Sattelmayer","doi":"10.1115/1.4063780","DOIUrl":"https://doi.org/10.1115/1.4063780","url":null,"abstract":"Abstract This paper presents an analysis of the unsteady heat release rate response of industrially relevant axisymmetric premixed flames to harmonic velocity perturbations. The heat release rate response, quantified using the Flame Transfer Function (FTF) definition, is measured from an acoustically forced swirl burner under perfectly premixed conditions. To understand the features of the measured FTF, a physics based analytical model is developed in this study. To describe the heat release rate dynamics, a model for the flame spatiotemporal response is derived in the linear limit using the G-equation formulation. Inputs to the flame response model are selected to be consistent with values observed in the corresponding industrial burner, based on experimental and numerical studies. The relative contributions of acoustic and convecting vortical disturbances on specific features of the FTF are explored in this study. The results highlight the importance of capturing the appropriate disturbance velocity field as an input to the flame response model for accurate FTF predictions.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136115186","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 Two non-destructive techniques for the identification of hot corrosion damage on internal surfaces were investigated: magnetic permeability measurements and x-ray computed tomography (CT). A group of sixty-one Solar Titan 130 stage 1 blades which were known to have hot corrosion damage on the internal surfaces at a specific location were used for the investigation. X-ray CT was able to accurately identify the presence of hot corrosion as well as the extent to which it had progressed through the wall at the location of interest. The magnetic permeability technique was found to accurately identify whether hot corrosion damage had occurred at the location of interest, but could not as accurately determine the extent to which the damage had progressed through the wall. The results of the non-destructive testing were validated by destructive examination of some blades. The non-destructive testing methods evaluated through the study were able to determine the presence and extent of localized hot corrosion damage on internal surfaces, allowing for higher repair yields.
{"title":"Non-Destructive Inspection of Hot Corrosion Damage On Internal Surfaces of Turbine Blades","authors":"Justin Kuipers, Kevin Wiens","doi":"10.1115/1.4063770","DOIUrl":"https://doi.org/10.1115/1.4063770","url":null,"abstract":"Abstract Two non-destructive techniques for the identification of hot corrosion damage on internal surfaces were investigated: magnetic permeability measurements and x-ray computed tomography (CT). A group of sixty-one Solar Titan 130 stage 1 blades which were known to have hot corrosion damage on the internal surfaces at a specific location were used for the investigation. X-ray CT was able to accurately identify the presence of hot corrosion as well as the extent to which it had progressed through the wall at the location of interest. The magnetic permeability technique was found to accurately identify whether hot corrosion damage had occurred at the location of interest, but could not as accurately determine the extent to which the damage had progressed through the wall. The results of the non-destructive testing were validated by destructive examination of some blades. The non-destructive testing methods evaluated through the study were able to determine the presence and extent of localized hot corrosion damage on internal surfaces, allowing for higher repair yields.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136116757","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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