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Emil Göttlich - One of the best experts on this subject based on the ideXlab platform.
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Impact of Varying High- and Low-Pressure Turbine Purge Flows on a Turbine Center Frame and Low-Pressure Turbine System
Journal of Turbomachinery, 2020Co-Authors: P. Z. Sterzinger, Stefan Zerobin, F. Merli, L. Wiesinger, Andreas Peters, G. Maini, M. Dellacasagrande, Franz Heitmeir, Emil GöttlichAbstract:Abstract This paper presents the experimental and numerical evaluation and comparison of the different flow fields downstream of a Turbine center frame duct and a low-Pressure Turbine (LPT) stage, generated by varying the inlet flow conditions to the Turbine center frame (TCF) duct. The measurements were carried out in an engine-representative two-stage two-spool test Turbine facility at the Institute for Thermal Turbomachinery and Machine Dynamics at Graz University of Technology. The rig consists of a high-Pressure Turbine (HPT) and a LPT Turbine stage, connected via a TCF with non-turning struts. Four individual high-Pressure Turbine purge flowrates and two low-Pressure Turbine purge flowrates were varied to achieve different engine-relevant TCF and LPT inlet flow conditions. The experimental data were acquired by means of five-hole-probe (5HP) area traverses upstream and downstream of the TCF and downstream of the LPT. A steady Reynolds-averaged Navier–Stokes (RANS) simulation taking all purge flows in account was used for comparison, and additional insights are gained from a numerical variation of the HPT and LPT purge flowrates. The focus of this study is on the impact of the variations in TCF inlet conditions on the secondary flow generation through the TCF duct and the carryover effects on the exit flow field and performance of the LPT stage. Existing work is limited by either investigating multistage LPT configurations with generally very few measurements behind the first stage or by not including relevant HPT secondary flow structures in setting up the LPT inflow conditions. This work addresses both of these shortcomings and presents new insight into the TCF and LPT aerodynamic behavior at varying the HPT and LPT purge flows. The results demonstrate the importance of the HPT flow structures and their evolution through the TCF duct for setting up the LPT inflow conditions and ultimately for assessing the performance of the first LPT stage.
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Impact of varying high- and low-Pressure Turbine purge flows on a Turbine center frame and low-Pressure Turbine system
Volume 2B: Turbomachinery, 2019Co-Authors: P. Z. Sterzinger, Stefan Zerobin, F. Merli, L. Wiesinger, Andreas Peters, G. Maini, M. Dellacasagrande, Franz Heitmeir, Emil GöttlichAbstract:Abstract This paper presents the experimental and numerical evaluation and comparison of the different flow fields downstream of a Turbine center frame duct and a low-Pressure Turbine stage, generated by varying the inlet flow conditions to the Turbine center frame duct. The measurements were carried out in an engine-representative two-stage two-spool test Turbine facility at the Institute for Thermal Turbomachinery and Machine Dynamics at Graz University of Technology. The rig consists of a high-Pressure (HPT) and a low-Pressure (LPT) Turbine stage, connected via a Turbine center frame (TCF) with non-turning struts. Four individual high-Pressure Turbine purge flow rates and two low-Pressure Turbine purge flow rates were varied to achieve different engine-relevant TCF and LPT inlet flow conditions. The experimental data was acquired by means of five-hole-probe area traverses upstream and downstream of the TCF, and downstream of the LPT. A steady RANS simulation taking all purge flows in account was used for comparison and additional insight are gained from a numerical variation of the HPT and LPT purge flow rates. The focus of this study is on the impact of the variations in TCF inlet conditions on the secondary flow generation through the TCF duct and the carry-over effects on the exit flow field and performance of the LPT stage. Existing work is limited by either investigating multi-stage LPT configurations with generally very few measurements behind the first stage or by not including relevant HPT secondary flow structures in setting up the LPT inflow conditions. This work addresses both of these shortcomings and presents new insight into the TCF and LPT aerodynamic behavior at varying the HPT and LPT purge flows. The results demonstrate the importance of the HPT flow structures and their evolution through the TCF duct for setting up the LPT inflow conditions, and ultimately for assessing the performance of the first LPT stage.
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The Unsteady Flow Field of a Purged High Pressure Turbine Based on Mode Detection
Volume 2D: Turbomachinery, 2017Co-Authors: Stefan Zerobin, Andreas Peters, Franz Heitmeir, Sabine Bauinger, Andreas Marn, Emil GöttlichAbstract:This paper presents an experimental study of the unsteady flow field downstream of a high Pressure Turbine with ejected purge flows, with a special focus on a flow field discussion using the mode detection approach according to the theory of Tyler and Sofrin. Measurements were carried out in a product-representative one and a half stage Turbine test setup, which consists of a high-Pressure Turbine stage followed by an intermediate Turbine center frame and a low-Pressure Turbine vane row. Four independent purge mass flows were injected through the forward and aft cavities of the unshrouded high-Pressure Turbine rotor. A fast-response Pressure probe was used to acquire time-resolved data at the Turbine center frame duct inlet and exit. The interactions between the stator, rotor, and Turbine center frame duct are identified as spinning modes, propagating in azimuthal direction. Time-space diagrams illustrate the amplitude variation of the detected modes along the span. The composition of the unsteadiness and its major contributors are of interest to determine the role of unsteadiness in the Turbine center frame duct loss generation mechanisms and to avoid high levels of blade vibrations in the low-Pressure Turbine which can in turn result in increased acoustic emissions. This work offers new insight into the unsteady flow behavior downstream of a purged high-Pressure Turbine and its propagation through an engine-representative Turbine center frame duct configuration.
Rolf Sondergaard - One of the best experts on this subject based on the ideXlab platform.
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Toward the Expansion of Low-Pressure-Turbine Airfoil Design Space
Journal of Turbomachinery, 2013Co-Authors: T. J. Praisner, E. A. Grover, D. C. Knezevici, I. Popovic, S. A. Sjolander, J. P. Clark, Rolf SondergaardAbstract:Future engine requirements, including high-altitude flight of unmanned air vehicles as well as an impetus to reduce engine cost and weight, are challenging the current state of the art in low-Pressure-Turbine airfoil design. These new requirements present low-Reynolds number challenges as well as the need for high-performance, high-lift design concepts. Here, we report on an effort to expand the relatively well established aerodynamic design space for low-Pressure Turbine airfoils through the application of recent developments in transition modeling to airfoil design. Analytical and experimental midspan performance data and predicted loadings are presented for four high-lift airfoil designs based on the Pack B velocity triangles. The new designs represent a systematic expansion of low-Pressure Turbine airfoil design space through the application of high-lift design concepts for front- and aft-loaded airfoils. All four designs performed as predicted across a range of operationally representative Reynolds numbers. Full-span loss data for the new high-lift designs reveal increased endwall losses, which, with the application of nonaxisymmetric endwall contouring, have been substantially reduced. Taken holistically, the results presented here demonstrate that accurate transition modeling provides a reliable method to develop optimized, very high-lift airfoil designs. However, further improvements in endwall-loss mitigation technologies are required to enable the implementation of the very high-lift technology presented here in engine systems.
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Experimental Investigation of a High-Lift Low-Pressure Turbine Suction Surface
AIAA Journal, 2010Co-Authors: Mark Mcquilling, Mitch Wolff, Sergey Fonov, Jim Crafton, Rolf SondergaardAbstract:This work employs a shear and stress sensitive film (S3F) to investigate the suction surface flow features associated with a higher-lift low-Pressure Turbine airfoil (L2F). Well-behaved higher-lift low-Pressure Turbine designs suffer from an inability to accurately predict the transition location above the suction surface, and the separation onset locations obtained with the S3F sensor herein allow the validation of the separated-flow transition model used in the L2F design cycle. Improvements to the S3F measurement technique are explained in this work, and results are compared over a range of Reynolds numbers at 3.3 % freestream turbulence including skin friction measurements at the trailing edge of the airfoil. Results demonstrate an improvement to the S3F data reduction process by accounting for the tunnel and model vibration, which will allow a greater range of sensor application.
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Toward the Expansion of Low-Pressure-Turbine Airfoil Design Space (Postprint)
2008Co-Authors: T. J. Praisner, Rolf Sondergaard, E. A. Grover, D. C. Knezevici, I. Popovic, S. A. Sjolander, J. P. Clark, P. J. KochAbstract:Abstract : Future engine requirements, including high-altitude flight of unmanned air vehicles as well as a movement to reduce engine cost and weight, are challenging the current state of the art in low-Pressure-Turbine airfoil design. These new requirements present low-Reynolds number challenges as well as the need for high-performance high-lift design concepts. Here we report on an effort to expand the relatively well established design space for low-Pressure Turbine airfoils. Analytical and experimental mid-span performance data and loadings are presented for four new airfoil designs based on the Pack B velocity triangles. The new designs represent a systematic expansion of low-Pressure Turbine airfoil design space through the application of high-lift design concepts for front- and aft-loaded airfoils. Taken holistically, the results presented here demonstrate accurate transition modeling provides a reliable method to develop optimized, very high-lift airfoil designs.
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toward the expansion of low Pressure Turbine airfoil design space
ASME Turbo Expo 2008: Power for Land Sea and Air, 2008Co-Authors: T. J. Praisner, E. A. Grover, D. C. Knezevici, I. Popovic, S. A. Sjolander, J. P. Clark, Rolf SondergaardAbstract:Future engine requirements, including high-altitude flight of unmanned air vehicles, as well as an impetus to reduce engine cost and weight, are challenging the current state of the art in low-Pressure-Turbine airfoil design. These new requirements present low-Reynolds number challenges as well as the need for high-performance, high-lift design concepts. Here we report on an effort to expand the relatively well established aerodynamic design space for low-Pressure Turbine airfoils through the application of recent developments in transition modeling to airfoil design. Analytical and experimental mid-span performance data and predicted loadings are presented for four high-lift airfoil designs based on the Pack B velocity triangles. The new designs represent a systematic expansion of low-Pressure Turbine airfoil design space through the application of high-lift design concepts for front- and aft-loaded airfoils. All four designs performed as predicted across a range of operationally representative Reynolds numbers. Full-span loss data for the new high-lift designs reveal increased endwall losses, which, with the application of non-axisymmetric endwall contouring, have been substantially reduced. Taken holistically, the results presented here demonstrate that accurate transition modeling provides a reliable method to develop optimized, very high-lift airfoil designs. However, further improvements in endwall-loss mitigation technologies are required to enable the implementation of the very high-lift technology presented here in engine systems.© 2008 ASME
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An Experimental Investigation of Low-Pressure Turbine Blade Suction Surface Stresses Using S3F (Preprint)
2006Co-Authors: Mark Mcquilling, Mitch Wolff, Sergey Fonov, Jim Crafton, Rolf SondergaardAbstract:Abstract : A shear and stress sensitive film (S3F) is employed on the suction surface of an industry standard low-Pressure Turbine blade. These tests address the optimization of S3F for low-speed air investigations on a curved surface, and are the first measurements of its kind. S3F provides all three stress components on a surface in a single measurement, and is based on 3D elastic deformations of a polymeric film. New composition films have been developed, and results over a range of Re respective of LPT flow conditions illustrate the need for separate films tailored for the local stress levels in each area.
Congtruong Dinh - One of the best experts on this subject based on the ideXlab platform.
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numerical aero thermal study of high Pressure Turbine nozzle guide vane effects of inflow conditions
Physics of Fluids, 2020Co-Authors: H M Phan, P H Duan, Congtruong DinhAbstract:Accurate predictability of high-Pressure Turbine nozzle guide vane aero-thermal performance is highly desired in the development campaign due to the exposure of the component to a frequent and high...
P. Z. Sterzinger - One of the best experts on this subject based on the ideXlab platform.
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Impact of Varying High- and Low-Pressure Turbine Purge Flows on a Turbine Center Frame and Low-Pressure Turbine System
Journal of Turbomachinery, 2020Co-Authors: P. Z. Sterzinger, Stefan Zerobin, F. Merli, L. Wiesinger, Andreas Peters, G. Maini, M. Dellacasagrande, Franz Heitmeir, Emil GöttlichAbstract:Abstract This paper presents the experimental and numerical evaluation and comparison of the different flow fields downstream of a Turbine center frame duct and a low-Pressure Turbine (LPT) stage, generated by varying the inlet flow conditions to the Turbine center frame (TCF) duct. The measurements were carried out in an engine-representative two-stage two-spool test Turbine facility at the Institute for Thermal Turbomachinery and Machine Dynamics at Graz University of Technology. The rig consists of a high-Pressure Turbine (HPT) and a LPT Turbine stage, connected via a TCF with non-turning struts. Four individual high-Pressure Turbine purge flowrates and two low-Pressure Turbine purge flowrates were varied to achieve different engine-relevant TCF and LPT inlet flow conditions. The experimental data were acquired by means of five-hole-probe (5HP) area traverses upstream and downstream of the TCF and downstream of the LPT. A steady Reynolds-averaged Navier–Stokes (RANS) simulation taking all purge flows in account was used for comparison, and additional insights are gained from a numerical variation of the HPT and LPT purge flowrates. The focus of this study is on the impact of the variations in TCF inlet conditions on the secondary flow generation through the TCF duct and the carryover effects on the exit flow field and performance of the LPT stage. Existing work is limited by either investigating multistage LPT configurations with generally very few measurements behind the first stage or by not including relevant HPT secondary flow structures in setting up the LPT inflow conditions. This work addresses both of these shortcomings and presents new insight into the TCF and LPT aerodynamic behavior at varying the HPT and LPT purge flows. The results demonstrate the importance of the HPT flow structures and their evolution through the TCF duct for setting up the LPT inflow conditions and ultimately for assessing the performance of the first LPT stage.
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Impact of varying high- and low-Pressure Turbine purge flows on a Turbine center frame and low-Pressure Turbine system
Volume 2B: Turbomachinery, 2019Co-Authors: P. Z. Sterzinger, Stefan Zerobin, F. Merli, L. Wiesinger, Andreas Peters, G. Maini, M. Dellacasagrande, Franz Heitmeir, Emil GöttlichAbstract:Abstract This paper presents the experimental and numerical evaluation and comparison of the different flow fields downstream of a Turbine center frame duct and a low-Pressure Turbine stage, generated by varying the inlet flow conditions to the Turbine center frame duct. The measurements were carried out in an engine-representative two-stage two-spool test Turbine facility at the Institute for Thermal Turbomachinery and Machine Dynamics at Graz University of Technology. The rig consists of a high-Pressure (HPT) and a low-Pressure (LPT) Turbine stage, connected via a Turbine center frame (TCF) with non-turning struts. Four individual high-Pressure Turbine purge flow rates and two low-Pressure Turbine purge flow rates were varied to achieve different engine-relevant TCF and LPT inlet flow conditions. The experimental data was acquired by means of five-hole-probe area traverses upstream and downstream of the TCF, and downstream of the LPT. A steady RANS simulation taking all purge flows in account was used for comparison and additional insight are gained from a numerical variation of the HPT and LPT purge flow rates. The focus of this study is on the impact of the variations in TCF inlet conditions on the secondary flow generation through the TCF duct and the carry-over effects on the exit flow field and performance of the LPT stage. Existing work is limited by either investigating multi-stage LPT configurations with generally very few measurements behind the first stage or by not including relevant HPT secondary flow structures in setting up the LPT inflow conditions. This work addresses both of these shortcomings and presents new insight into the TCF and LPT aerodynamic behavior at varying the HPT and LPT purge flows. The results demonstrate the importance of the HPT flow structures and their evolution through the TCF duct for setting up the LPT inflow conditions, and ultimately for assessing the performance of the first LPT stage.
Stefan Zerobin - One of the best experts on this subject based on the ideXlab platform.
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Impact of Varying High- and Low-Pressure Turbine Purge Flows on a Turbine Center Frame and Low-Pressure Turbine System
Journal of Turbomachinery, 2020Co-Authors: P. Z. Sterzinger, Stefan Zerobin, F. Merli, L. Wiesinger, Andreas Peters, G. Maini, M. Dellacasagrande, Franz Heitmeir, Emil GöttlichAbstract:Abstract This paper presents the experimental and numerical evaluation and comparison of the different flow fields downstream of a Turbine center frame duct and a low-Pressure Turbine (LPT) stage, generated by varying the inlet flow conditions to the Turbine center frame (TCF) duct. The measurements were carried out in an engine-representative two-stage two-spool test Turbine facility at the Institute for Thermal Turbomachinery and Machine Dynamics at Graz University of Technology. The rig consists of a high-Pressure Turbine (HPT) and a LPT Turbine stage, connected via a TCF with non-turning struts. Four individual high-Pressure Turbine purge flowrates and two low-Pressure Turbine purge flowrates were varied to achieve different engine-relevant TCF and LPT inlet flow conditions. The experimental data were acquired by means of five-hole-probe (5HP) area traverses upstream and downstream of the TCF and downstream of the LPT. A steady Reynolds-averaged Navier–Stokes (RANS) simulation taking all purge flows in account was used for comparison, and additional insights are gained from a numerical variation of the HPT and LPT purge flowrates. The focus of this study is on the impact of the variations in TCF inlet conditions on the secondary flow generation through the TCF duct and the carryover effects on the exit flow field and performance of the LPT stage. Existing work is limited by either investigating multistage LPT configurations with generally very few measurements behind the first stage or by not including relevant HPT secondary flow structures in setting up the LPT inflow conditions. This work addresses both of these shortcomings and presents new insight into the TCF and LPT aerodynamic behavior at varying the HPT and LPT purge flows. The results demonstrate the importance of the HPT flow structures and their evolution through the TCF duct for setting up the LPT inflow conditions and ultimately for assessing the performance of the first LPT stage.
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Impact of varying high- and low-Pressure Turbine purge flows on a Turbine center frame and low-Pressure Turbine system
Volume 2B: Turbomachinery, 2019Co-Authors: P. Z. Sterzinger, Stefan Zerobin, F. Merli, L. Wiesinger, Andreas Peters, G. Maini, M. Dellacasagrande, Franz Heitmeir, Emil GöttlichAbstract:Abstract This paper presents the experimental and numerical evaluation and comparison of the different flow fields downstream of a Turbine center frame duct and a low-Pressure Turbine stage, generated by varying the inlet flow conditions to the Turbine center frame duct. The measurements were carried out in an engine-representative two-stage two-spool test Turbine facility at the Institute for Thermal Turbomachinery and Machine Dynamics at Graz University of Technology. The rig consists of a high-Pressure (HPT) and a low-Pressure (LPT) Turbine stage, connected via a Turbine center frame (TCF) with non-turning struts. Four individual high-Pressure Turbine purge flow rates and two low-Pressure Turbine purge flow rates were varied to achieve different engine-relevant TCF and LPT inlet flow conditions. The experimental data was acquired by means of five-hole-probe area traverses upstream and downstream of the TCF, and downstream of the LPT. A steady RANS simulation taking all purge flows in account was used for comparison and additional insight are gained from a numerical variation of the HPT and LPT purge flow rates. The focus of this study is on the impact of the variations in TCF inlet conditions on the secondary flow generation through the TCF duct and the carry-over effects on the exit flow field and performance of the LPT stage. Existing work is limited by either investigating multi-stage LPT configurations with generally very few measurements behind the first stage or by not including relevant HPT secondary flow structures in setting up the LPT inflow conditions. This work addresses both of these shortcomings and presents new insight into the TCF and LPT aerodynamic behavior at varying the HPT and LPT purge flows. The results demonstrate the importance of the HPT flow structures and their evolution through the TCF duct for setting up the LPT inflow conditions, and ultimately for assessing the performance of the first LPT stage.
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The Unsteady Flow Field of a Purged High Pressure Turbine Based on Mode Detection
Volume 2D: Turbomachinery, 2017Co-Authors: Stefan Zerobin, Andreas Peters, Franz Heitmeir, Sabine Bauinger, Andreas Marn, Emil GöttlichAbstract:This paper presents an experimental study of the unsteady flow field downstream of a high Pressure Turbine with ejected purge flows, with a special focus on a flow field discussion using the mode detection approach according to the theory of Tyler and Sofrin. Measurements were carried out in a product-representative one and a half stage Turbine test setup, which consists of a high-Pressure Turbine stage followed by an intermediate Turbine center frame and a low-Pressure Turbine vane row. Four independent purge mass flows were injected through the forward and aft cavities of the unshrouded high-Pressure Turbine rotor. A fast-response Pressure probe was used to acquire time-resolved data at the Turbine center frame duct inlet and exit. The interactions between the stator, rotor, and Turbine center frame duct are identified as spinning modes, propagating in azimuthal direction. Time-space diagrams illustrate the amplitude variation of the detected modes along the span. The composition of the unsteadiness and its major contributors are of interest to determine the role of unsteadiness in the Turbine center frame duct loss generation mechanisms and to avoid high levels of blade vibrations in the low-Pressure Turbine which can in turn result in increased acoustic emissions. This work offers new insight into the unsteady flow behavior downstream of a purged high-Pressure Turbine and its propagation through an engine-representative Turbine center frame duct configuration.