Abstract The integrated design of a variable cycle engine (VCE) and an aircraft thermal management system (TMS) is investigated. The integrated system is designed using the multiple design point approach in order to achieve required performance metrics at points other than the cycle design condition. The VCE architecture is a three stream design where the third stream is split off after the fan, exhausting through a separate third-stream nozzle. The primary air stream passes through a low-pressure compressor before splitting into an inner bypass stream and a core stream. The inner streams mix aft of the low-pressure turbine and exhaust through a core nozzle. The variable cycle engine utilizes variable compressor inlet guide vanes, a variable area bypass injector at the core stream mixing plane, and variable throats in the two exhaust nozzles. The TMS architecture is an air cycle system using air bled from the high-pressure compressor. The effect of integrating the TMS into the engine design loop is investigated. A comparison is made to prior studies where the same TMS architecture was connected to a low bypass ratio turbofan engine. The comparison shows that the variable cycle engine is able to improve heat dissipation capability versus a ram air cooled system, while eliminating the airframe integration impact that comes with a separate ram-air stream. Lastly, the impact of modulating the variable geometry features on overall cooling capability is investigated. Results are presented for individual operating points as well as at the aircraft mission level.
{"title":"Integrated Design Of A Variable Cycle Engine And Aircraft Thermal Management System","authors":"Robert Clark, Jimmy C.M. Tai, Dimitri N. Mavris","doi":"10.1115/1.4063866","DOIUrl":"https://doi.org/10.1115/1.4063866","url":null,"abstract":"Abstract The integrated design of a variable cycle engine (VCE) and an aircraft thermal management system (TMS) is investigated. The integrated system is designed using the multiple design point approach in order to achieve required performance metrics at points other than the cycle design condition. The VCE architecture is a three stream design where the third stream is split off after the fan, exhausting through a separate third-stream nozzle. The primary air stream passes through a low-pressure compressor before splitting into an inner bypass stream and a core stream. The inner streams mix aft of the low-pressure turbine and exhaust through a core nozzle. The variable cycle engine utilizes variable compressor inlet guide vanes, a variable area bypass injector at the core stream mixing plane, and variable throats in the two exhaust nozzles. The TMS architecture is an air cycle system using air bled from the high-pressure compressor. The effect of integrating the TMS into the engine design loop is investigated. A comparison is made to prior studies where the same TMS architecture was connected to a low bypass ratio turbofan engine. The comparison shows that the variable cycle engine is able to improve heat dissipation capability versus a ram air cooled system, while eliminating the airframe integration impact that comes with a separate ram-air stream. Lastly, the impact of modulating the variable geometry features on overall cooling capability is investigated. Results are presented for individual operating points as well as at the aircraft mission level.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135513157","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}
Davide Cerbarano, Lorenzo Tieghi, Giovanni Delibra, Ermanno Lo Schiavo, Stefano Minotti, Alessandro Corsini
Abstract Reduction of gas turbines carbon emissions relies on a strategy for fueling the engines with pure or blended hydrogen. The major technical challenges to solve are i) the adjustments to the engine and in particular the combustion chamber and ii) a series of issues to solve to guarantee safe operations. In fact, compared to natural gas, hydrogen fueling implies higher risks of explosion in case of leak in the turbine enclosure and a more careful design of the ventilation system. Thus, a deeper comprehension of hydrogen leak scenarios is needed to adjust the safe design strategy of the enclosure. To this aim, a series of numerical investigations was carried out to understand how different methane-hydrogen blends (from pure methane to pure hydrogen) behave when leaking from a pipeline with fuel pressure that span from 1.5 to 4.5 MPa. The different fuel blends leaks in form of under-expanded jets were studied under different cross-flow ventilation conditions, with ventilation velocity spanning from 0 m/s to 5m/s. When compared to pure methane, the outcome is a three times longer penetration distance for pure hydrogen axisymmetric flammable clouds, whereas in cross-flow conditions a more complex three-dimensional behavior was found, potentially opening a safety-related concerns discussed in the manuscript.
{"title":"Characterization of High-Pressure Hydrogen Leakages","authors":"Davide Cerbarano, Lorenzo Tieghi, Giovanni Delibra, Ermanno Lo Schiavo, Stefano Minotti, Alessandro Corsini","doi":"10.1115/1.4063830","DOIUrl":"https://doi.org/10.1115/1.4063830","url":null,"abstract":"Abstract Reduction of gas turbines carbon emissions relies on a strategy for fueling the engines with pure or blended hydrogen. The major technical challenges to solve are i) the adjustments to the engine and in particular the combustion chamber and ii) a series of issues to solve to guarantee safe operations. In fact, compared to natural gas, hydrogen fueling implies higher risks of explosion in case of leak in the turbine enclosure and a more careful design of the ventilation system. Thus, a deeper comprehension of hydrogen leak scenarios is needed to adjust the safe design strategy of the enclosure. To this aim, a series of numerical investigations was carried out to understand how different methane-hydrogen blends (from pure methane to pure hydrogen) behave when leaking from a pipeline with fuel pressure that span from 1.5 to 4.5 MPa. The different fuel blends leaks in form of under-expanded jets were studied under different cross-flow ventilation conditions, with ventilation velocity spanning from 0 m/s to 5m/s. When compared to pure methane, the outcome is a three times longer penetration distance for pure hydrogen axisymmetric flammable clouds, whereas in cross-flow conditions a more complex three-dimensional behavior was found, potentially opening a safety-related concerns discussed in the manuscript.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135778853","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}
Luming Fan, Bruno Savard, Benoit Fond, Antoine Durocher, Jeffrey Bergthorson, Spencer Carlyle, Patrizio Vena
Abstract In gas turbines, confined highly turbulent flames unavoidably propagate in the vicinity of a relatively cool combustor liner, affecting both the local flame structure and global operation of the combustion system. In our recent work, we demonstrated, using simultaneous [OH] × [CH2O] PLIF and stereo-PIV, that lean CH4/H2 flames at a high Karlovitz number can present a highly broken structure near wall, highlighted by a diffuse CH2O cloud which suggests local quenching and incomplete oxidation. Such high Karlovitz numbers were achieved using an inclined plate, which substantially extended the lean flammability of the low swirl flames. Yet, how a cooled wall acting as a heat sink played a conducive role in stabilizing high Ka flames remains unanswered. Here, we look to better understand the stabilization mechanisms for lean and ultra-lean flames on the same configuration, and how they may change with a parametric variation of plate incident angle, plate-nozzle distance, and bulk velocity up to the critical values that lead to flame blow off. The results show that the impinging swirling flow creates a low speed region that helps hold the flame, while the wall prevents mixing with ambient cold air. The production of diffuse CH2O, which indicates the occurrence of local quenching, is associated with a mean strain rate beyond the extinction strain rate. High H2 fraction flames appear to be more robust to persistent strain rate, thus extending their stability envelope. However, these flames can subsist as highly broken flames featuring strong incomplete combustion.
{"title":"Mechanisms Leading to Stabilization and Incomplete Combustion in Lean CH4/H2 Swirling Wall-Impinging Flames","authors":"Luming Fan, Bruno Savard, Benoit Fond, Antoine Durocher, Jeffrey Bergthorson, Spencer Carlyle, Patrizio Vena","doi":"10.1115/1.4063833","DOIUrl":"https://doi.org/10.1115/1.4063833","url":null,"abstract":"Abstract In gas turbines, confined highly turbulent flames unavoidably propagate in the vicinity of a relatively cool combustor liner, affecting both the local flame structure and global operation of the combustion system. In our recent work, we demonstrated, using simultaneous [OH] × [CH2O] PLIF and stereo-PIV, that lean CH4/H2 flames at a high Karlovitz number can present a highly broken structure near wall, highlighted by a diffuse CH2O cloud which suggests local quenching and incomplete oxidation. Such high Karlovitz numbers were achieved using an inclined plate, which substantially extended the lean flammability of the low swirl flames. Yet, how a cooled wall acting as a heat sink played a conducive role in stabilizing high Ka flames remains unanswered. Here, we look to better understand the stabilization mechanisms for lean and ultra-lean flames on the same configuration, and how they may change with a parametric variation of plate incident angle, plate-nozzle distance, and bulk velocity up to the critical values that lead to flame blow off. The results show that the impinging swirling flow creates a low speed region that helps hold the flame, while the wall prevents mixing with ambient cold air. The production of diffuse CH2O, which indicates the occurrence of local quenching, is associated with a mean strain rate beyond the extinction strain rate. High H2 fraction flames appear to be more robust to persistent strain rate, thus extending their stability envelope. However, these flames can subsist as highly broken flames featuring strong incomplete combustion.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135779148","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}
Simone Castellani, Pier Carlo Nassini, Antonio Andreini, Roberto Meloni, Egidio Pucci, Agustin Valera Medina, Steven Morris, Burak Goktepe, Syed Mashruk
Abstract The lean premixed technology is a very convenient combustion strategy to progressively move from natural gas to high hydrogen content fuels in gas turbines limiting the pollutants emissions at the same time. The enabling process that will allow the combustor to manage a full H2 operation requires relevant design modifications, and in this framework, the numerical modelling will be a pivotal tool that will support this transition. In this work, high-fidelity simulations of perfectly premixed swirl stabilized flames have been performed varying the H2 content in the fuel from 0 to 100% to investigate the effect of the hydrogen addition on the methane flame. The artificially thickened flame model (ATFM) has been used to treat the turbulent chemistry interaction. The numerical results have been compared with the detailed experimental data performed at Cardiff University's Gas Turbine Research Centre. After the numerical model validation against experimental OH* chemiluminescence maps has been presented, a deep numerical investigation of the effect of the H2 addition on the flame has been performed. In this way, the work aims to highlight the good prediction capability of the ATFM, and, at the same time, highlight the change in the different contributions that govern the flame reactivity moving from 100% CH4 to 100% H2 in very lean conditions.
{"title":"Numerical Modelling of Swirl Stabilised Lean-Premixed H2-CH4 Flames with the Artificially Thickened Flame Model","authors":"Simone Castellani, Pier Carlo Nassini, Antonio Andreini, Roberto Meloni, Egidio Pucci, Agustin Valera Medina, Steven Morris, Burak Goktepe, Syed Mashruk","doi":"10.1115/1.4063829","DOIUrl":"https://doi.org/10.1115/1.4063829","url":null,"abstract":"Abstract The lean premixed technology is a very convenient combustion strategy to progressively move from natural gas to high hydrogen content fuels in gas turbines limiting the pollutants emissions at the same time. The enabling process that will allow the combustor to manage a full H2 operation requires relevant design modifications, and in this framework, the numerical modelling will be a pivotal tool that will support this transition. In this work, high-fidelity simulations of perfectly premixed swirl stabilized flames have been performed varying the H2 content in the fuel from 0 to 100% to investigate the effect of the hydrogen addition on the methane flame. The artificially thickened flame model (ATFM) has been used to treat the turbulent chemistry interaction. The numerical results have been compared with the detailed experimental data performed at Cardiff University's Gas Turbine Research Centre. After the numerical model validation against experimental OH* chemiluminescence maps has been presented, a deep numerical investigation of the effect of the H2 addition on the flame has been performed. In this way, the work aims to highlight the good prediction capability of the ATFM, and, at the same time, highlight the change in the different contributions that govern the flame reactivity moving from 100% CH4 to 100% H2 in very lean conditions.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135729626","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 increase in renewable energy penetration on the grid has accelerated the need to transition conventional fossil-based energy sources from their traditional base load operation to more flexible operational regimes. The mode of operation changed dramatically in terms of number of starts, operating hours per annum and variation in load level. This results in greater thermal transients on operational equipment leading to an increase in Low Cycle Fatigue damage. To ensure the continued integrity of the steam turbine components, it is essential to assess the lifetime status by applying Residual Lifetime Analysis methods. Depending on the amount of lifetime consumption and the extend of potential crack findings, different component repair options are possible. The rework or repair options can be divided into two main groups, namely cold- and hot-rework. These two options can also be carried out consecutively. All rework or repair options provide the opportunity to improve the application of a component by applying profiling with improved stress fields and even superior materials, in the case of hot rework. The aim of the rework / re-conditioning is to ensure that the steam turbine component is suitable for future operation. This ensures that plants are well placed to deliver more flexible operation in the energy industry through carefully tailored refurbishments and reworks.
{"title":"Rework and Repair Options for Steam Turbine Components Subject to Flexible Operation","authors":"Frank Biesinger, Huascar Lorini, Ritesh Shah","doi":"10.1115/1.4063835","DOIUrl":"https://doi.org/10.1115/1.4063835","url":null,"abstract":"Abstract The increase in renewable energy penetration on the grid has accelerated the need to transition conventional fossil-based energy sources from their traditional base load operation to more flexible operational regimes. The mode of operation changed dramatically in terms of number of starts, operating hours per annum and variation in load level. This results in greater thermal transients on operational equipment leading to an increase in Low Cycle Fatigue damage. To ensure the continued integrity of the steam turbine components, it is essential to assess the lifetime status by applying Residual Lifetime Analysis methods. Depending on the amount of lifetime consumption and the extend of potential crack findings, different component repair options are possible. The rework or repair options can be divided into two main groups, namely cold- and hot-rework. These two options can also be carried out consecutively. All rework or repair options provide the opportunity to improve the application of a component by applying profiling with improved stress fields and even superior materials, in the case of hot rework. The aim of the rework / re-conditioning is to ensure that the steam turbine component is suitable for future operation. This ensures that plants are well placed to deliver more flexible operation in the energy industry through carefully tailored refurbishments and reworks.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135730789","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 understanding of processes that govern soot production in aero-engines is fundamental for the design of new combustion systems with low environmental impact. Many combustors, more specifically those used in aero-engines, feature rich flame regions typically exploited in the so-called Rich-Quench-Lean technology. Thus, it is important to consider rich turbulent flames operating in the premixed mode. To this purpose, a model scale swirled combustor, called EM2Soot, was designed at the EM2C laboratory to analyze soot production under perfectly premixed rich conditions. In this work, the effect of the equivalence ratio on soot production in this burner is experimentally characterized and numerically simulated. Measurements of Planar Laser Induced Fluorescence of Polycyclic Aromatic Hydrocarbons were performed to examine soot precursors presence, whereas soot volume fraction is measured with Planar Laser Induced Incandescence. Large Eddy Simulations (LES) are carried out using models already established in literature. By considering a range of equivalence ratios, the soot volume fraction from the experiments was found to reach a maximum near 1.8, whereas a lower level of soot volume fraction was measured for lower and for higher equivalence ratios. The large eddy simulations are found to be in qualitative agreement with experimental data in terms of PAHs and soot location. The soot volume fractions fv are notably overestimated with respect to the LII measurements. However, the numerical results correctly retrieve a reduction of soot production for the highest considered equivalence ratio value and can be used to explain the experimental behaviour.
{"title":"Role of the Equivalence Ratio On Soot Formation in a Perfectly Premixed Turbulent Swirled Flame: A Combined Experimental and Les Study","authors":"Aurora Maffina, Mathieu Roussillo, Philippe Scouflaire, Nasser Darabiha, Denis Veynante, Sebastien Candel, Benedetta Franzelli","doi":"10.1115/1.4063832","DOIUrl":"https://doi.org/10.1115/1.4063832","url":null,"abstract":"Abstract The understanding of processes that govern soot production in aero-engines is fundamental for the design of new combustion systems with low environmental impact. Many combustors, more specifically those used in aero-engines, feature rich flame regions typically exploited in the so-called Rich-Quench-Lean technology. Thus, it is important to consider rich turbulent flames operating in the premixed mode. To this purpose, a model scale swirled combustor, called EM2Soot, was designed at the EM2C laboratory to analyze soot production under perfectly premixed rich conditions. In this work, the effect of the equivalence ratio on soot production in this burner is experimentally characterized and numerically simulated. Measurements of Planar Laser Induced Fluorescence of Polycyclic Aromatic Hydrocarbons were performed to examine soot precursors presence, whereas soot volume fraction is measured with Planar Laser Induced Incandescence. Large Eddy Simulations (LES) are carried out using models already established in literature. By considering a range of equivalence ratios, the soot volume fraction from the experiments was found to reach a maximum near 1.8, whereas a lower level of soot volume fraction was measured for lower and for higher equivalence ratios. The large eddy simulations are found to be in qualitative agreement with experimental data in terms of PAHs and soot location. The soot volume fractions fv are notably overestimated with respect to the LII measurements. However, the numerical results correctly retrieve a reduction of soot production for the highest considered equivalence ratio value and can be used to explain the experimental behaviour.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135779311","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}
Edoardo Gheller, Vishnu Vardhan Reddy, Satish Koyyalamudi, Steven Chatterton, Daniele Panara, Paolo Pennacchi
Abstract The necessity of increasing the efficiency and reducing the carbon foot-print of machines is pushing centrifugal compressor bearings design to higher and higher peripheral speed and lower oil consumptions especially in the new energy transition fields, resulting in an increase in the bearing temperatures. Therefore, the bearing thermal management starts to play a major role in extending the machine operability and reducing the maintenance frequency. A full three-dimensional (3D) parametric conjugate heat transfer Computational Fluid Dynamic (CFD) model for Tilting Pad Journal Bearings (TPJBs) is introduced in this paper to address the temperature aspects of oil-film bearings. The parametric geometry of the model and the automatic mesh update, allow the equilibrium position search to be obtained without adopting any dynamic mesh algorithms. The tilting pad and rotating shaft equilibrium position is automatically calculated with a Newton-Raphson algorithm. The static performance of the TPJB is investigated for different journal diameters, bearing clearance, and operating conditions. The numerical results obtained are compared with experimental data from Compressor Mechanical Running Tests to demonstrate the reliability of the model presented. The 3D distributions of the oil pressure, velocity and temperature given by the CFD model, can be locally optimized to face the new energy transition challenges.
{"title":"Tilting Pad Journal Bearing CFD Parametric Modeling for New Energy Transition Challenges","authors":"Edoardo Gheller, Vishnu Vardhan Reddy, Satish Koyyalamudi, Steven Chatterton, Daniele Panara, Paolo Pennacchi","doi":"10.1115/1.4063831","DOIUrl":"https://doi.org/10.1115/1.4063831","url":null,"abstract":"Abstract The necessity of increasing the efficiency and reducing the carbon foot-print of machines is pushing centrifugal compressor bearings design to higher and higher peripheral speed and lower oil consumptions especially in the new energy transition fields, resulting in an increase in the bearing temperatures. Therefore, the bearing thermal management starts to play a major role in extending the machine operability and reducing the maintenance frequency. A full three-dimensional (3D) parametric conjugate heat transfer Computational Fluid Dynamic (CFD) model for Tilting Pad Journal Bearings (TPJBs) is introduced in this paper to address the temperature aspects of oil-film bearings. The parametric geometry of the model and the automatic mesh update, allow the equilibrium position search to be obtained without adopting any dynamic mesh algorithms. The tilting pad and rotating shaft equilibrium position is automatically calculated with a Newton-Raphson algorithm. The static performance of the TPJB is investigated for different journal diameters, bearing clearance, and operating conditions. The numerical results obtained are compared with experimental data from Compressor Mechanical Running Tests to demonstrate the reliability of the model presented. The 3D distributions of the oil pressure, velocity and temperature given by the CFD model, can be locally optimized to face the new energy transition challenges.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135779313","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 Current U.S. government policy seeks to achieve a carbon-free economy by 2050, with a carbon-free electricity sector by 2035 (per executive orders #14008 and #14057). To address these goals, the U.S. Department of Energy is evaluating technologies that support the production, utilization, transport, and storage of hydrogen (via initiatives like DOE's Energy Earthshots and various DOE funding opportunity announcements). A carbon-free fuel like hydrogen is valuable for a dynamic electric energy sector seeking to decarbonize. One of the most important technologies needed to achieve this carbon-free electricity sector is a 100% hydrogen-fueled gas turbine. Accommodating hydrogen fuels has been a key goal for various original engine manufacturers (OEMs) for many years, but more research and development (R&D) is needed. The purpose of this paper is to highlight the current state-of-the- art of hydrogen turbine technology, especially regarding nitrogen oxide (NOX) emissions, compared to natural gas turbines. NOX is the primary criteria pollutant from thermally-driven combustion turbines and should be controlled to levels that are below current standards. This paper provides an overview of hydrogen as a fuel and various NOX control techniques that are relevant for hydrogen-based fuels. A conclusion from this overview is that, with some level of R&D, NOX emissions from hydrogen-fueled gas turbines can be controlled to levels similar to those produced by state-of-the-art natural gas-fueled combustion turbines while remaining competitive in terms of performance and efficiency.
{"title":"A Literature Review of Nox Emissions in Current and Future State-of-the-art Gas Turbines","authors":"Richard Dennis, Henry Long, Gary Jesionowski","doi":"10.1115/1.4063836","DOIUrl":"https://doi.org/10.1115/1.4063836","url":null,"abstract":"Abstract Current U.S. government policy seeks to achieve a carbon-free economy by 2050, with a carbon-free electricity sector by 2035 (per executive orders #14008 and #14057). To address these goals, the U.S. Department of Energy is evaluating technologies that support the production, utilization, transport, and storage of hydrogen (via initiatives like DOE's Energy Earthshots and various DOE funding opportunity announcements). A carbon-free fuel like hydrogen is valuable for a dynamic electric energy sector seeking to decarbonize. One of the most important technologies needed to achieve this carbon-free electricity sector is a 100% hydrogen-fueled gas turbine. Accommodating hydrogen fuels has been a key goal for various original engine manufacturers (OEMs) for many years, but more research and development (R&D) is needed. The purpose of this paper is to highlight the current state-of-the- art of hydrogen turbine technology, especially regarding nitrogen oxide (NOX) emissions, compared to natural gas turbines. NOX is the primary criteria pollutant from thermally-driven combustion turbines and should be controlled to levels that are below current standards. This paper provides an overview of hydrogen as a fuel and various NOX control techniques that are relevant for hydrogen-based fuels. A conclusion from this overview is that, with some level of R&D, NOX emissions from hydrogen-fueled gas turbines can be controlled to levels similar to those produced by state-of-the-art natural gas-fueled combustion turbines while remaining competitive in terms of performance and efficiency.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135779315","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}
Yuchen Dai, Manxiang Song, Donghai Jin, Xingmin Gui, Xiaoheng Liu
Abstract Current research on engine transient performance primarily focuses on the variation of key aerothermodynamic parameters in specific sections, neglecting the comprehensive understanding of the engine's inner flow field during transient operations. To address this gap, this paper proposes a 2D transient simulation method that effectively captures the evolution of the flow field in the meridional plane. The approach involves deriving circumferential averaging equations in a rotating coordinate system with variable angular velocity, considering angular acceleration source terms. The engine components, including the compressor, combustion chamber, turbine, and rotating shaft, are individually modeled. The newly derived governing equations are solved using a dual-time step approach, where an inner-iteration ensures mass flow conservation, and an outer-iteration updates the rotational speed. Using a real turbojet engine as a case study, transient examinations comprising acceleration and deceleration are performed. A comparative analysis of experimental and simulation results is conducted, revealing an average error of 0.9% in shaft speed, 7.8% in engine thrust, 1.7% in engine exhaust temperature, and 5.1% in compressor outlet pressure. Additionally, the study analyzes and compares the internal flow fields during the transient process, contributing to a deeper understanding of the engine's dynamic behavior. The research effort establishes a practical methodology and technology for conducting comprehensive two-dimensional engine transient cycle analyses within reasonable computational resources and timeframes.
{"title":"Transient Performance Simulation of Gas Turbine Engine Based On Through-Flow Method and Experimental Verification","authors":"Yuchen Dai, Manxiang Song, Donghai Jin, Xingmin Gui, Xiaoheng Liu","doi":"10.1115/1.4063828","DOIUrl":"https://doi.org/10.1115/1.4063828","url":null,"abstract":"Abstract Current research on engine transient performance primarily focuses on the variation of key aerothermodynamic parameters in specific sections, neglecting the comprehensive understanding of the engine's inner flow field during transient operations. To address this gap, this paper proposes a 2D transient simulation method that effectively captures the evolution of the flow field in the meridional plane. The approach involves deriving circumferential averaging equations in a rotating coordinate system with variable angular velocity, considering angular acceleration source terms. The engine components, including the compressor, combustion chamber, turbine, and rotating shaft, are individually modeled. The newly derived governing equations are solved using a dual-time step approach, where an inner-iteration ensures mass flow conservation, and an outer-iteration updates the rotational speed. Using a real turbojet engine as a case study, transient examinations comprising acceleration and deceleration are performed. A comparative analysis of experimental and simulation results is conducted, revealing an average error of 0.9% in shaft speed, 7.8% in engine thrust, 1.7% in engine exhaust temperature, and 5.1% in compressor outlet pressure. Additionally, the study analyzes and compares the internal flow fields during the transient process, contributing to a deeper understanding of the engine's dynamic behavior. The research effort establishes a practical methodology and technology for conducting comprehensive two-dimensional engine transient cycle analyses within reasonable computational resources and timeframes.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135729630","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}
David John Rajendran, Kyril Palaveev, Eduardo Anselmi, Mani Santhanakrishnan, Vassilios Pachidis
Abstract A flow field analysis of a realistic, integrated, multi-disc boundary layer pump as is necessary for investigating the reasons for typically quoted low efficiencies in such pumps is described. The study focuses on the 3D RANS solutions of a water boundary layer pump model created to replicate a design which consists of 170 discs and a volute channel. A baseline study is performed to investigate the rotor-only and volute-only flow fields and identify the losses in each as separate systems. Thereafter, an integrated model is characterized for different operating conditions. The flow fields of all three models are discussed and the results of the integrated model are compared to the experimental data. The results from the rotor-only model confirm the typically made claim that the rotor efficiency is relatively high, which in this case is 87% at the design point. The volute on its own indicated a hydraulic efficiency of ~97%. However, the integrated model yielded a rotor efficiency of ~74% and an overall pump efficiency of 51% at the design point, clearly outlining the fact that the effect of the volute integrated with the rotor is the reason for both the rotor and pump efficiency degradation. The reason for this drop in efficiency is discussed by highlighting the change in the flow topologies. The insights into the flow field and the identification of the reason for inefficiencies using a separated component analysis approach provides directions for avenues in which design improvements need to be attempted.
{"title":"Insights Into the Flow Field and Performance of a Boundary Layer Pump","authors":"David John Rajendran, Kyril Palaveev, Eduardo Anselmi, Mani Santhanakrishnan, Vassilios Pachidis","doi":"10.1115/1.4063834","DOIUrl":"https://doi.org/10.1115/1.4063834","url":null,"abstract":"Abstract A flow field analysis of a realistic, integrated, multi-disc boundary layer pump as is necessary for investigating the reasons for typically quoted low efficiencies in such pumps is described. The study focuses on the 3D RANS solutions of a water boundary layer pump model created to replicate a design which consists of 170 discs and a volute channel. A baseline study is performed to investigate the rotor-only and volute-only flow fields and identify the losses in each as separate systems. Thereafter, an integrated model is characterized for different operating conditions. The flow fields of all three models are discussed and the results of the integrated model are compared to the experimental data. The results from the rotor-only model confirm the typically made claim that the rotor efficiency is relatively high, which in this case is 87% at the design point. The volute on its own indicated a hydraulic efficiency of ~97%. However, the integrated model yielded a rotor efficiency of ~74% and an overall pump efficiency of 51% at the design point, clearly outlining the fact that the effect of the volute integrated with the rotor is the reason for both the rotor and pump efficiency degradation. The reason for this drop in efficiency is discussed by highlighting the change in the flow topologies. The insights into the flow field and the identification of the reason for inefficiencies using a separated component analysis approach provides directions for avenues in which design improvements need to be attempted.","PeriodicalId":15685,"journal":{"name":"Journal of Engineering for Gas Turbines and Power-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135779320","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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