Lakshya Bhatnagar, G. Paniagua, D. G. Cuadrado, Papa Aye N. Aye-Addo, Antonio Castillo Sauca, F. Lozano, Matthew J. Bloxham
The betterment of the turbine performance plays a prime role in all future transportation and energy production systems. Precise uncertainty quantification of experimental measurement of any performance differential is therefore essential for turbine development programs. In this paper, the uncertainty analysis of loss measurements in a high-pressure turbine vane are presented. Tests were performed on a stator geometry at engine representative conditions in a new annular turbine module called BRASTA (Big Rig for Annular Stationary Turbine Analysis) located within the Purdue Experimental Turbine Aerothermal Lab. The aerodynamic probes are described with emphasis on their calibration and uncertainty analysis, first considering single point measurement, followed by the spatial averaging implications. The change of operating conditions and flow blockage due to measurement probes are analyzed using CFD, and corrections are recommended on the measurement data. The test section and its characterization are presented, including calibration of the sonic valve. The sonic valve calibration is necessary to ensure a wide range of operation in Mach and Reynolds. Finally, the vane data are discussed, emphasizing their systematic and stochastic uncertainty.
{"title":"Uncertainty in High-Pressure Stator Performance Measurement in an Annular Cascade at Engine-Representative Reynolds and Mach","authors":"Lakshya Bhatnagar, G. Paniagua, D. G. Cuadrado, Papa Aye N. Aye-Addo, Antonio Castillo Sauca, F. Lozano, Matthew J. Bloxham","doi":"10.1115/gt2021-59702","DOIUrl":"https://doi.org/10.1115/gt2021-59702","url":null,"abstract":"\u0000 The betterment of the turbine performance plays a prime role in all future transportation and energy production systems. Precise uncertainty quantification of experimental measurement of any performance differential is therefore essential for turbine development programs. In this paper, the uncertainty analysis of loss measurements in a high-pressure turbine vane are presented. Tests were performed on a stator geometry at engine representative conditions in a new annular turbine module called BRASTA (Big Rig for Annular Stationary Turbine Analysis) located within the Purdue Experimental Turbine Aerothermal Lab. The aerodynamic probes are described with emphasis on their calibration and uncertainty analysis, first considering single point measurement, followed by the spatial averaging implications. The change of operating conditions and flow blockage due to measurement probes are analyzed using CFD, and corrections are recommended on the measurement data. The test section and its characterization are presented, including calibration of the sonic valve. The sonic valve calibration is necessary to ensure a wide range of operation in Mach and Reynolds. Finally, the vane data are discussed, emphasizing their systematic and stochastic uncertainty.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114177881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benjamin Fietzke, R. King, Jan Mihalyovics, D. Peitsch
Novel pressure gain combustion concepts invoke periodic flow disturbances in a gas turbine’s last compressor stator row. This contribution presents studies of mitigation efforts on the effects of these periodic disturbances on an annular compressor stator rig. The passages were equipped with pneumatic Active Flow Control (AFC) influencing the stator blade’s suction side, and a rotating throttling disc downstream of the passages inducing periodic disturbances. For steady blowing, it is shown that with increasing actuation amplitudes Cμ, the extension of a hub corner vortex deteriorating the suction side flow can be reduced, resulting in an increased static pressure rise coefficient Cp of a passage. The effects of the induced periodic disturbances could not be addressed intrinsically, by using steady blowing actuation, Considering a corrected total pressure loss coefficient ζ*, which includes the actuation effort, the stator row’s efficiency decreases with higher cμ due to the increasing costs of the actuation mass flow. Therefore, a closed-loop approach is presented to address the effects of the disturbances more specifically, thus lowering the actuation cost, i.e., mass flow. For this, a Repetitive Model Predictive Control (RMPC) was applied, taking advantage of the periodic nature of the induced disturbances. The presented RMPC formulation is restricted to a binary control domain to account for the used solenoid valves’ switching character. An efficient implementation of the optimization within the RMPC is presented, which ensures real-time capability. As a result, Cp increases in a similar magnitude but with a lower actuation mass flow of up to 66%, resulting in a much lower ζ* for similar values of cμ.
{"title":"Binary Repetitive Model Predictive Active Flow Control Applied to an Annular Compressor Stator Cascade With Periodic Disturbances","authors":"Benjamin Fietzke, R. King, Jan Mihalyovics, D. Peitsch","doi":"10.1115/gt2021-58744","DOIUrl":"https://doi.org/10.1115/gt2021-58744","url":null,"abstract":"\u0000 Novel pressure gain combustion concepts invoke periodic flow disturbances in a gas turbine’s last compressor stator row. This contribution presents studies of mitigation efforts on the effects of these periodic disturbances on an annular compressor stator rig. The passages were equipped with pneumatic Active Flow Control (AFC) influencing the stator blade’s suction side, and a rotating throttling disc downstream of the passages inducing periodic disturbances. For steady blowing, it is shown that with increasing actuation amplitudes Cμ, the extension of a hub corner vortex deteriorating the suction side flow can be reduced, resulting in an increased static pressure rise coefficient Cp of a passage. The effects of the induced periodic disturbances could not be addressed intrinsically, by using steady blowing actuation, Considering a corrected total pressure loss coefficient ζ*, which includes the actuation effort, the stator row’s efficiency decreases with higher cμ due to the increasing costs of the actuation mass flow. Therefore, a closed-loop approach is presented to address the effects of the disturbances more specifically, thus lowering the actuation cost, i.e., mass flow. For this, a Repetitive Model Predictive Control (RMPC) was applied, taking advantage of the periodic nature of the induced disturbances. The presented RMPC formulation is restricted to a binary control domain to account for the used solenoid valves’ switching character. An efficient implementation of the optimization within the RMPC is presented, which ensures real-time capability. As a result, Cp increases in a similar magnitude but with a lower actuation mass flow of up to 66%, resulting in a much lower ζ* for similar values of cμ.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115927350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Air-steam Dual Loop Gas Turbine Engine (DLGTE) consists of a gas turbine engine with Pulse Detonation Combustor (PDC) (operating by the Humphrey cycle) with the air as the working fluid and a steam turbine engine (operating by the Rankine cycle) with the steam as the working fluid. The temperature of the hot detonation products is reduced to Turbine Inlet Temperature (TIT) by exchanging heat energy between detonation products and water in a Detonation Products to Water Heat Exchanger (DPWHE). The thermodynamic cycle of operation of DLGTE with PDC is analyzed based on quasi-steady state one dimensional formulation, and a computer code is developed in MATLAB to simulate the engine performance at different compressor pressure ratios and TITs. C2H4/air is taken as the fuel-oxidizer. It is found that DLGTE with PDC achieves 40 to 47% thermal efficiency as against 20 to 35% of Base Line Gas Turbine Engine (BLGTE) and 27 to 40% of Combined Cycle Gas Turbine Engine (CCGTE) with a Steady Flow Combustor (SFC) depending on the cycle pressure ratios and TITs. The specific work output of DLGTE is found to increase from 875 to 1200 kJ/kg air as against 180 to 380 kJ/kg air of BLGTE and 200 to 430 kJ/kg air of CCGTE.
{"title":"Air-Steam Dual Loop Gas Turbine Engine With Pulse Detonation Combustion","authors":"Pereddy Nageswara Reddy","doi":"10.1115/gt2021-59983","DOIUrl":"https://doi.org/10.1115/gt2021-59983","url":null,"abstract":"\u0000 Air-steam Dual Loop Gas Turbine Engine (DLGTE) consists of a gas turbine engine with Pulse Detonation Combustor (PDC) (operating by the Humphrey cycle) with the air as the working fluid and a steam turbine engine (operating by the Rankine cycle) with the steam as the working fluid. The temperature of the hot detonation products is reduced to Turbine Inlet Temperature (TIT) by exchanging heat energy between detonation products and water in a Detonation Products to Water Heat Exchanger (DPWHE). The thermodynamic cycle of operation of DLGTE with PDC is analyzed based on quasi-steady state one dimensional formulation, and a computer code is developed in MATLAB to simulate the engine performance at different compressor pressure ratios and TITs. C2H4/air is taken as the fuel-oxidizer. It is found that DLGTE with PDC achieves 40 to 47% thermal efficiency as against 20 to 35% of Base Line Gas Turbine Engine (BLGTE) and 27 to 40% of Combined Cycle Gas Turbine Engine (CCGTE) with a Steady Flow Combustor (SFC) depending on the cycle pressure ratios and TITs. The specific work output of DLGTE is found to increase from 875 to 1200 kJ/kg air as against 180 to 380 kJ/kg air of BLGTE and 200 to 430 kJ/kg air of CCGTE.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132953234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The hot-wire anemometer is a widely used instrumentation to determine flow velocity and to investigate flow quality. The main objective of this paper is to expand the application range of the hot wire by improving the measurement accuracy under non-calibrated temperature and pressure. According to the four kinds of heat transfer derivations, a new calibration method was carried out. Considering natural convection, heat radiation and heat conduction, and forced convection heat transfer, it can be found that the forced convection heat transfer plays a dominant role, and the main factor causing the change is the temperature. Forced convection heat transfer also changes with pressure, which affects heat transfer by affecting kinematic viscosity. Based on this, a new calibration method and formula of velocity were put forward, which can be used over a range of temperature and pressure, considering the changes of physical property of the calibration scheme were verified by numerical simulation. The numerical calculated results were compared, the average error was 0.69%, the maximum error was 2.9%. The results show that the calibration method has high accuracy in a certain range. This paper provides a new solution for the calibration of hot-wire anemometer, and expands the adaptability of hot-wire anemometer in the measurement of severe external conditions.
{"title":"Hot-Wire Measurements in Non-Calibrated Conditions","authors":"Yuexin Wang, T. Guo, Hui-ren Zhu","doi":"10.1115/gt2021-59259","DOIUrl":"https://doi.org/10.1115/gt2021-59259","url":null,"abstract":"\u0000 The hot-wire anemometer is a widely used instrumentation to determine flow velocity and to investigate flow quality. The main objective of this paper is to expand the application range of the hot wire by improving the measurement accuracy under non-calibrated temperature and pressure. According to the four kinds of heat transfer derivations, a new calibration method was carried out. Considering natural convection, heat radiation and heat conduction, and forced convection heat transfer, it can be found that the forced convection heat transfer plays a dominant role, and the main factor causing the change is the temperature. Forced convection heat transfer also changes with pressure, which affects heat transfer by affecting kinematic viscosity. Based on this, a new calibration method and formula of velocity were put forward, which can be used over a range of temperature and pressure, considering the changes of physical property of the calibration scheme were verified by numerical simulation. The numerical calculated results were compared, the average error was 0.69%, the maximum error was 2.9%. The results show that the calibration method has high accuracy in a certain range. This paper provides a new solution for the calibration of hot-wire anemometer, and expands the adaptability of hot-wire anemometer in the measurement of severe external conditions.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114962209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, MHPS achieved a NET M501J gas turbine combined cycle (GTCC) efficiency in excess of 62% operating at 1,600°C, while maintaining NOx under 25ppm. Taking advantage of our gas turbine combustion design, development and operational experience, retrofits of earlier generation gas turbines have been successfully applied and will be described in this paper. One example of the latest J-Series technologies, a conventional pilot nozzle was changed to a premix type pilot nozzle for low emission. The technology was retrofitted to the existing F-Series gas turbines, which resulted in emission rates of lower than 9ppm NOx(15%O2) while maintaining the same Turbine Inlet Temperature (TIT: Average Gas Temperature at the exit of the transition piece). After performing retrofitting design, high pressure rig tests, the field test prior to commercial operation was conducted on January 2019. This paper describes the Ultra-Low NOx combustor design features, retrofit design, high pressure rig test and verification test results of the upgraded M501F gas turbine. In addition, it describes another upgrade of turbine to improve efficiency and of combustion control system to achieve low emissions. Furthermore it describes the trouble-free upgrade of seven (7) units, which was completed by utilizing MHPS integration capabilities, including handling all the design, construction and service work of the main equipment, plant and control systems.
{"title":"Application of Ultra-Low NOx Combustor to the MHPS Existing Gas Turbine","authors":"Takashi Nishiumi, Hirofumi Ohara, Kotaro Miyauchi, Sosuke Nakamura, T. Ai, Masahito Kataoka","doi":"10.1115/gt2021-02403","DOIUrl":"https://doi.org/10.1115/gt2021-02403","url":null,"abstract":"In recent years, MHPS achieved a NET M501J gas turbine combined cycle (GTCC) efficiency in excess of 62% operating at 1,600°C, while maintaining NOx under 25ppm. Taking advantage of our gas turbine combustion design, development and operational experience, retrofits of earlier generation gas turbines have been successfully applied and will be described in this paper. One example of the latest J-Series technologies, a conventional pilot nozzle was changed to a premix type pilot nozzle for low emission. The technology was retrofitted to the existing F-Series gas turbines, which resulted in emission rates of lower than 9ppm NOx(15%O2) while maintaining the same Turbine Inlet Temperature (TIT: Average Gas Temperature at the exit of the transition piece). After performing retrofitting design, high pressure rig tests, the field test prior to commercial operation was conducted on January 2019. This paper describes the Ultra-Low NOx combustor design features, retrofit design, high pressure rig test and verification test results of the upgraded M501F gas turbine. In addition, it describes another upgrade of turbine to improve efficiency and of combustion control system to achieve low emissions. Furthermore it describes the trouble-free upgrade of seven (7) units, which was completed by utilizing MHPS integration capabilities, including handling all the design, construction and service work of the main equipment, plant and control systems.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128358299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Warren, Hessein Ali, Hossein Ebrahimi, Hossein Ebrahimi
Several image processing methods have been implemented over recent years to assist and partially replace on-site technician visual inspection of both manufactured parts and operational equipments. Convolutional neural networks (CNNs) have seen great success in their ability to both identify and classify anomalies within images, in some cases they do this to a higher degree of accuracy than an expert human. Several parts that are manufactured for various aspects of turbomachinery operation must undergo a visual inspection prior to qualification. Machine learning techniques can streamline these visual inspection processes and increase both efficiency and accuracy of defect detection and classification. The adoption of CNNs to manufactured part inspection can also help to improve manufacturing methods by rapidly retrieving data for overall system improvement. In this work a dataset of images with a variety of surface defects and some without defects will be fed through varying CNN set-ups for the rapid identification and classification of the flaws within the images. This work will examine the techniques used to create CNNs and how they can best be applied to part surface image data, and determine the most accurate and efficient techniques that should be implemented. By combining machine learning with non-destructive evaluation methods component health can be rapidly determined and create a more robust system for manufactured parts and operational equipment evaluation.
{"title":"Rapid Defect Detection and Classification in Images Using Convolutional Neural Networks","authors":"P. Warren, Hessein Ali, Hossein Ebrahimi, Hossein Ebrahimi","doi":"10.1115/gt2021-59801","DOIUrl":"https://doi.org/10.1115/gt2021-59801","url":null,"abstract":"\u0000 Several image processing methods have been implemented over recent years to assist and partially replace on-site technician visual inspection of both manufactured parts and operational equipments. Convolutional neural networks (CNNs) have seen great success in their ability to both identify and classify anomalies within images, in some cases they do this to a higher degree of accuracy than an expert human. Several parts that are manufactured for various aspects of turbomachinery operation must undergo a visual inspection prior to qualification. Machine learning techniques can streamline these visual inspection processes and increase both efficiency and accuracy of defect detection and classification. The adoption of CNNs to manufactured part inspection can also help to improve manufacturing methods by rapidly retrieving data for overall system improvement. In this work a dataset of images with a variety of surface defects and some without defects will be fed through varying CNN set-ups for the rapid identification and classification of the flaws within the images. This work will examine the techniques used to create CNNs and how they can best be applied to part surface image data, and determine the most accurate and efficient techniques that should be implemented. By combining machine learning with non-destructive evaluation methods component health can be rapidly determined and create a more robust system for manufactured parts and operational equipment evaluation.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125538896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aircraft operators rely on gas path analysis techniques for monitoring the performance and health of their gas turbine engine assets. This is accomplished by analyzing discernable shifts in measurement parameters acquired from the engine. This paper reviews the founding mathematical principles of gas path analysis, including conventional approaches applied for estimating engine performance deterioration. Considerations for extending the application of gas path analysis techniques to Electrified Aircraft Propulsion (EAP) systems is also discussed, and simulated results from their application to an EAP concept comprised of turbomachinery and electrical system hardware is provided. Results are provided comparing the parameter estimation accuracy offered by taking a whole-system approach towards the problem setup versus that offered by analyzing each subsystem individually. For the latter, the importance of having accurate direct or inferred measurements of external mechanical torque loads placed upon turbomachinery shafts is emphasized.
{"title":"Considerations for the Extension of Gas Path Analysis To Electrified Aircraft Propulsion Systems","authors":"D. Simon, Randy L. Thomas, Kyle Dunlap","doi":"10.1115/gt2021-58578","DOIUrl":"https://doi.org/10.1115/gt2021-58578","url":null,"abstract":"\u0000 Aircraft operators rely on gas path analysis techniques for monitoring the performance and health of their gas turbine engine assets. This is accomplished by analyzing discernable shifts in measurement parameters acquired from the engine. This paper reviews the founding mathematical principles of gas path analysis, including conventional approaches applied for estimating engine performance deterioration. Considerations for extending the application of gas path analysis techniques to Electrified Aircraft Propulsion (EAP) systems is also discussed, and simulated results from their application to an EAP concept comprised of turbomachinery and electrical system hardware is provided. Results are provided comparing the parameter estimation accuracy offered by taking a whole-system approach towards the problem setup versus that offered by analyzing each subsystem individually. For the latter, the importance of having accurate direct or inferred measurements of external mechanical torque loads placed upon turbomachinery shafts is emphasized.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121478880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Matthews, Anna Cobb, S. Adhikari, David Wu, T. Lieuwen, J. Blust, B. Emerson
Understanding thermoacoustic instabilities is essential for the reliable operation of gas turbine engines. To complicate this understanding, the extreme sensitivity of gas turbine combustors can lead to instability characteristics that differ across a fleet. The capability to monitor flame transfer functions in fielded engines would provide valuable data to improve this understanding and aid in gas turbine operability from R&D to field tuning. This paper presents a new experimental facility used to analyze performance of full-scale gas turbine fuel injector hardware at elevated pressure and temperature. It features a liquid cooled, fiber-coupled probe that provides direct optical access to the heat release zone for high-speed chemiluminescence measurements. The probe was designed with fielded applications in mind. In addition, the combustion chamber includes an acoustic sensor array and a large objective window for verification of the probe using high-speed chemiluminescence imaging. This work experimentally demonstrates the new setup under scaled engine conditions, with a focus on operational zones that yield interesting acoustic tones. Results include a demonstration of the probe, preliminary analysis of acoustic and high speed chemiluminescence data, and high speed chemiluminescence imaging. The novelty of this paper is the deployment of a new test platform that incorporates full-scale engine hardware and provides the ability to directly compare acoustic and heat release response in a high-temperature, high-pressure environment to determine the flame transfer functions. This work is a stepping-stone towards the development of an on-line flame transfer function measurement technique for production engines in the field.
{"title":"Experimental Development of On-Line Flame Transfer Function Measurements for Fielded Gas Turbines","authors":"A. Matthews, Anna Cobb, S. Adhikari, David Wu, T. Lieuwen, J. Blust, B. Emerson","doi":"10.1115/gt2021-59317","DOIUrl":"https://doi.org/10.1115/gt2021-59317","url":null,"abstract":"\u0000 Understanding thermoacoustic instabilities is essential for the reliable operation of gas turbine engines. To complicate this understanding, the extreme sensitivity of gas turbine combustors can lead to instability characteristics that differ across a fleet. The capability to monitor flame transfer functions in fielded engines would provide valuable data to improve this understanding and aid in gas turbine operability from R&D to field tuning. This paper presents a new experimental facility used to analyze performance of full-scale gas turbine fuel injector hardware at elevated pressure and temperature. It features a liquid cooled, fiber-coupled probe that provides direct optical access to the heat release zone for high-speed chemiluminescence measurements. The probe was designed with fielded applications in mind. In addition, the combustion chamber includes an acoustic sensor array and a large objective window for verification of the probe using high-speed chemiluminescence imaging. This work experimentally demonstrates the new setup under scaled engine conditions, with a focus on operational zones that yield interesting acoustic tones. Results include a demonstration of the probe, preliminary analysis of acoustic and high speed chemiluminescence data, and high speed chemiluminescence imaging. The novelty of this paper is the deployment of a new test platform that incorporates full-scale engine hardware and provides the ability to directly compare acoustic and heat release response in a high-temperature, high-pressure environment to determine the flame transfer functions. This work is a stepping-stone towards the development of an on-line flame transfer function measurement technique for production engines in the field.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"51 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120924227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Nicchiotti, S. A. Page, Krzysztof Soliński, Lukas Andracher, Nina Paulitsch, F. Giuliani
This paper introduces a novel approach to monitor pressure dynamics in turbomachinery. This innovation is motivated by the need expressed by machine OEMs and end-users to detect and avoid combustion instabilities, as well as lean-blowout (LBO), in low emission combustion systems. Such situations are often characterised by a marked increase of pressure signals in low frequency range. The piezoelectric technology, conventionally used for pressure measurements, presents sensitivity and stability issues at high temperatures and low frequencies. Here a new paradigm for pressure sensing, based on optical interferometry, is characterised and validated. The interferometric sensing system is designed to provide a larger range of measurement frequencies with better performance, in the low frequency range (< 50Hz), while exposed to high temperatures. This unique feature allows the real-time observation of events, such as the specific behaviour of a low frequency flame dynamic, which is characteristic of an imminent LBO. This improved monitoring system will support an optimisation of the machine performance, leading to a safer, cleaner, more flexible and more cost-efficient operation for the end-user. The novel measurement system has been characterised under non-reactive and reactive conditions within the frame of a joint study between Meggitt SA, Combustion Bay One e.U. and FH Joanneum GmbH. The technology is first described, including the relevant hardware and software components of the measurement chain. The different experimental set-ups and conditions are also illustrated. The results of the test campaign and their subsequent analysis are then presented, supporting the expected advantages over piezoelectric technology. In conclusion, a possible strategy for the detection of LBO precursors based on low frequency data is proposed.
本文介绍了一种监测涡轮机械压力动态的新方法。这项创新的动机是机器oem和最终用户对检测和避免低排放燃烧系统中的燃烧不稳定性以及稀爆(LBO)的需求。这种情况的特点通常是在低频范围内压力信号显著增加。传统上用于压力测量的压电技术在高温和低频下存在灵敏度和稳定性问题。在这里,一种新的压力传感范例,基于光学干涉测量,是表征和验证。该干涉传感系统旨在提供更大范围的测量频率和更好的性能,在低频范围内(< 50Hz),同时暴露在高温下。这种独特的功能允许实时观察事件,例如低频火焰动态的特定行为,这是即将发生的杠杆收购的特征。这种改进的监控系统将支持机器性能的优化,从而为最终用户带来更安全、更清洁、更灵活和更具成本效益的操作。在Meggitt SA、Combustion Bay One e.U.和FH Joanneum GmbH的联合研究框架内,这种新型测量系统在非反应和反应条件下进行了表征。首先描述了该技术,包括测量链的相关硬件和软件组件。并说明了不同的实验装置和条件。测试活动的结果及其随后的分析,然后提出,支持预期的优势优于压电技术。综上所述,本文提出了一种基于低频数据的LBO前体检测策略。
{"title":"Characterisation and Validation of an Optical Pressure Sensor for Combustion Monitoring at Low Frequency","authors":"G. Nicchiotti, S. A. Page, Krzysztof Soliński, Lukas Andracher, Nina Paulitsch, F. Giuliani","doi":"10.1115/gt2021-59103","DOIUrl":"https://doi.org/10.1115/gt2021-59103","url":null,"abstract":"\u0000 This paper introduces a novel approach to monitor pressure dynamics in turbomachinery. This innovation is motivated by the need expressed by machine OEMs and end-users to detect and avoid combustion instabilities, as well as lean-blowout (LBO), in low emission combustion systems. Such situations are often characterised by a marked increase of pressure signals in low frequency range. The piezoelectric technology, conventionally used for pressure measurements, presents sensitivity and stability issues at high temperatures and low frequencies. Here a new paradigm for pressure sensing, based on optical interferometry, is characterised and validated.\u0000 The interferometric sensing system is designed to provide a larger range of measurement frequencies with better performance, in the low frequency range (< 50Hz), while exposed to high temperatures. This unique feature allows the real-time observation of events, such as the specific behaviour of a low frequency flame dynamic, which is characteristic of an imminent LBO. This improved monitoring system will support an optimisation of the machine performance, leading to a safer, cleaner, more flexible and more cost-efficient operation for the end-user.\u0000 The novel measurement system has been characterised under non-reactive and reactive conditions within the frame of a joint study between Meggitt SA, Combustion Bay One e.U. and FH Joanneum GmbH. The technology is first described, including the relevant hardware and software components of the measurement chain. The different experimental set-ups and conditions are also illustrated. The results of the test campaign and their subsequent analysis are then presented, supporting the expected advantages over piezoelectric technology. In conclusion, a possible strategy for the detection of LBO precursors based on low frequency data is proposed.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"327 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115071499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Alexiou, Z. Vlahostergios, C. Salpingidou, F. Donus, D. Misirlis, K. Yakinthos
Aiming in the direction of designing high efficiency aircraft engines, various concepts have been developed in recent years, among which is the concept of the intercooled and recuperative aero engine (IRA engine). This concept is based on the use of a system of heat exchangers (recuperator) mounted inside the hot-gas exhaust nozzle, as well as a system of heat exchangers (intercooler) mounted between the intermittent-pressure compressor (IPC) and the high-pressure compressor (HPC) compressor modules. Through the operation of the system of recuperator module, the heat from the exhaust gas, downstream the LP turbine of the aero engine is driven back to the combustion chamber. Thus, the preheated air enters the engine combustion chamber with increased enthalpy, providing higher combustion efficiency and consequently reduced thrust specific fuel consumption (TSFC) and low-level emissions. Additionally, by integrating the intercooler module between the compressor stages of the aero engine, the compressed air is cooled, leading to less required compression work to reach the compressor target pressure and significant improvements can be achieved in the overall engine efficiency and the specific fuel consumption hence, contributing to the reduction of CO2 and NOx emissions. The present work is focused on the optimization of the performance characteristics of an intercooler specifically designed for aero engine applications, working cooperatively with a novel design recuperator module targeting the reduction of specific fuel consumption and taking into consideration aero engine geometrical constraints and limitations for two separate operating scenarios. The intercooler design was based on the elliptically profiled tubular heat exchanger which was developed and invented by MTU Aero Engines AG. For the specific fuel consumption investigations, the Intercooled Recuperated Aero engine cycle that combines both intercooling and recuperation was considered. The optimization was performed with the development of an intercooler surrogate model, capable to incorporate major geometrical features. A large number of intercooler design scenarios was assessed, in which additional design criteria and constraints were applied. Thus, a significantly large intercooler design space was covered resulting to the identification of feasible designs providing beneficial effect on the Intercooled Recuperated Aero engine performance leading to reduced specific fuel consumption, reduced weight and extended aircraft range.
{"title":"Intercooler Parametric Analysis for the IRA Engine Cycle Performance Augmentation","authors":"E. Alexiou, Z. Vlahostergios, C. Salpingidou, F. Donus, D. Misirlis, K. Yakinthos","doi":"10.1115/gt2021-59187","DOIUrl":"https://doi.org/10.1115/gt2021-59187","url":null,"abstract":"\u0000 Aiming in the direction of designing high efficiency aircraft engines, various concepts have been developed in recent years, among which is the concept of the intercooled and recuperative aero engine (IRA engine). This concept is based on the use of a system of heat exchangers (recuperator) mounted inside the hot-gas exhaust nozzle, as well as a system of heat exchangers (intercooler) mounted between the intermittent-pressure compressor (IPC) and the high-pressure compressor (HPC) compressor modules. Through the operation of the system of recuperator module, the heat from the exhaust gas, downstream the LP turbine of the aero engine is driven back to the combustion chamber. Thus, the preheated air enters the engine combustion chamber with increased enthalpy, providing higher combustion efficiency and consequently reduced thrust specific fuel consumption (TSFC) and low-level emissions. Additionally, by integrating the intercooler module between the compressor stages of the aero engine, the compressed air is cooled, leading to less required compression work to reach the compressor target pressure and significant improvements can be achieved in the overall engine efficiency and the specific fuel consumption hence, contributing to the reduction of CO2 and NOx emissions.\u0000 The present work is focused on the optimization of the performance characteristics of an intercooler specifically designed for aero engine applications, working cooperatively with a novel design recuperator module targeting the reduction of specific fuel consumption and taking into consideration aero engine geometrical constraints and limitations for two separate operating scenarios. The intercooler design was based on the elliptically profiled tubular heat exchanger which was developed and invented by MTU Aero Engines AG. For the specific fuel consumption investigations, the Intercooled Recuperated Aero engine cycle that combines both intercooling and recuperation was considered. The optimization was performed with the development of an intercooler surrogate model, capable to incorporate major geometrical features. A large number of intercooler design scenarios was assessed, in which additional design criteria and constraints were applied. Thus, a significantly large intercooler design space was covered resulting to the identification of feasible designs providing beneficial effect on the Intercooled Recuperated Aero engine performance leading to reduced specific fuel consumption, reduced weight and extended aircraft range.","PeriodicalId":169840,"journal":{"name":"Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124764357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}