Air Model Tests of Labyrinth Seal Forces on a Whirling Rotor

1978 ◽  
Vol 100 (4) ◽  
pp. 533-543 ◽  
Author(s):  
D. V. Wright
Keyword(s):  
High Pressure ◽  
Labyrinth Seal ◽  
Model Tests ◽  
Test Results ◽  
High Pressure Turbine ◽  
System Parameters ◽  
Valid Method ◽  
Radial Stiffness ◽  
Blade Row ◽  
Model Rotor

Steam-excited whirl of high pressure turbine rotors is caused by shroud and shaft labyrinth seal forces and by flow forces on the blades. Accurate test results are needed to guide development of a valid method for calculating labyrinth seal whirl forces and to verify the method. This paper describes apparatus for accurate measurement of labyrinth seal forces on a whirling model rotor. The effects of some system parameters on the whirl excitation constant (whirl force/whirl amplitude.) and radial stiffness of a model seal are shown. The seal whirl force is destabilizing for some conditions and stabilizing for others. A method is given for predicting the net seal and blade-row excitation constant that will cause self-excited whirl of rotors having specified shaft and bearing parameters.

Results From the Phase II Test Using the High-Temperature Developing Unit (HTDU)

1988 ◽  
Vol 110 (2) ◽  
pp. 251-258 ◽  
Author(s):  
S. Aoki ◽  
K. Teshima ◽  
M. Arai ◽  
H. Yamao
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Thermal Barrier Coating ◽  
Phase Ii ◽  
Thermal Barrier ◽  
Test Results ◽  
High Pressure Turbine ◽  
Barrier Coating ◽  
Two Stages

Phase II of the high-temperature turbine test was performed using the High-Temperature Developing Unit (HTDU). This unit has the same two stages as the high-pressure turbine of the AGTJ-100A reheat system. The purpose of the Phase II test was to investigate the potential of candidate technologies that may be applied to the advanced engine, the AGTJ-100B. Cooling characteristics of several cooling schemes for the first stage blades, and the performance of thermal barrier coating employed on the first stage nozzles and blades, were investigated. This paper presents the Phase II test results.

Design and Test Results of a Ultra High Loaded Single Stage High Pressure Turbine

2013 ◽  
Author(s):  
Harjit S. Hura ◽  
Scott Carson ◽  
Rob Saeidi ◽  
Hyoun-Woo Shin ◽  
Paul Giel
Keyword(s):  
High Pressure ◽  
Total Pressure ◽  
High Speed ◽  
Pressure Ratio ◽  
Single Stage ◽  
Test Results ◽  
High Pressure Turbine ◽  
Technology Program ◽  
High Pressure Ratio ◽  
Expected Performance

This paper describes the engine and rig design, and test results of an ultra-highly loaded single stage high pressure turbine. In service aviation single stage HPTs typically operate at a total-to-total pressure ratio of less than 4.0. At higher pressure ratios or energy extraction the nozzle and blade both have regions of supersonic flow and shock structures which, if not mitigated, can result in a large loss in efficiency both in the turbine itself and due to interaction with the downstream component which may be a turbine center frame or a low pressure turbine. Extending the viability of the single stage HPT to higher pressure ratios is attractive as it enables a compact engine with less weight, and lower initial and maintenance costs as compared to a two stage HPT. The present work was performed as part of the NASA UEET (Ultra-Efficient Engine Technology) program from 2002 through 2005. The goal of the program was to design and rig test a cooled single stage HPT with a pressure ratio of 5.5 with an efficiency at least two points higher than the state of the art. Preliminary design tools and a design of experiments approach were used to design the flow path. Stage loading and through-flow were set at appropriate levels based on prior experience on high pressure ratio single stage turbines. Appropriate choices of blade aspect ratio, count, and reaction were made based on comparison with similar HPT designs. A low shock blading design approach was used to minimize the shock strength in the blade during design iterations. CFD calculations were made to assess performance. The HPT aerodynamics and cooling design was replicated and tested in a high speed rig at design point and off-design conditions. The turbine met or exceeded the expected performance level based on both steady state and radial/circumferential traverse data. High frequency dynamic total pressure measurements were made to understand the presence of unsteadiness that persists in the exhaust of a transonic turbine.

Blade-Row Interaction in a High-Pressure Turbine

2001 ◽  
Vol 17 (4) ◽  
pp. 892-901 ◽  
Author(s):  
V. S. P. Chaluvadi ◽  
A. I. Kalfas ◽  
M. R. Banieghbal ◽  
H. P. Hodson ◽  
J. D. Denton
Keyword(s):  
High Pressure ◽  
High Pressure Turbine ◽  
Blade Row ◽  
Blade Row Interaction

Results From High Temperature Turbine Test on the HPT of the AGTJ-100A

1984 ◽  
Author(s):  
Masashi Arai ◽  
Kiyomi Teshima ◽  
Sunao Aoki ◽  
Hiroyuki Yamao
Keyword(s):  
Experimental Investigation ◽  
High Pressure ◽  
High Temperature ◽  
Aerodynamic Performance ◽  
Inlet Temperature ◽  
Test Results ◽  
Mechanical Reliability ◽  
High Pressure Turbine ◽  
Turbine Inlet Temperature ◽  
Turbine Efficiency

An experimental investigation was conducted through the use of a High Temperature Turbine Developing Unit (HTDU) having the same two stage turbine as the high pressure turbine (HPT) of the AGTJ-100A, to ascertain the aerodynamic performance, cooling characteristics and mechanical reliability. The test was performed in three phases, and the maximum turbine inlet temperature was about 1,573 K. The test results showed that turbine efficiency was 90.2 %, the level of metal temperature for nozzles and blades was as expected, and there was little trouble with the hot parts. This paper will present these test results.

Aerodynamics and Heat Transfer for a Cooled One and One-Half Stage High-Pressure Turbine—Part III: Impact of Hot-Streak Characteristics on Blade Row Heat Flux

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
R. M. Mathison ◽  
C. W. Haldeman ◽  
M. G. Dunn
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
Radial Profile ◽  
Leading Edge ◽  
Coolant Temperature ◽  
High Pressure Turbine ◽  
Blade Row ◽  
Hot Streak ◽  
The Impact

The influence of hot-streak magnitude and alignment relative to the vane leading edge on blade row heat flux is investigated for a one and one-half stage high-pressure turbine with a film-cooled vane, purge cooling, and uncooled blades. The full-stage turbine is operated at design-corrected conditions. In addition to investigating the impact of different hot-streak characteristics, this study also looks at the interaction of cooling flow with the hot streaks. This paper builds on the investigation of profile migration utilizing temperature measurements presented in Part I and the heat transfer measurements presented in Part II. Hot streaks aligned with the vane midpitch have a greater impact on blade temperatures and heat-flux values than hot streaks aligned with the vane leading edge. The leading edge hot streaks tend to be mixed out over the surface of the vane. The magnitude of the hot streak is observed to have the largest influence on the temperature and heat flux for the downstream blade. Time-accurate measurements confirm these conclusions and indicate that further analysis of the time-accurate data is warranted. Film cooling is found to impact a hot-streak profile in a way similar to that observed for a radial profile. Differences in core to coolant temperature ratio cause the uniform profile to show different coolant effects, but the overall spread of the cooling appears similar.

Unsteady Simulation of a Two-Stage Cooled High Pressure Turbine Using an Efficient Non-Linear Harmonic Balance Method

2013 ◽  
Author(s):  
Venkataramanan Subramanian ◽  
Chad H. Custer ◽  
Jonathan M. Weiss ◽  
Kenneth C. Hall
Keyword(s):  
High Pressure ◽  
Harmonic Balance ◽  
Nearest Neighbor ◽  
Harmonic Balance Method ◽  
Balance Method ◽  
High Pressure Turbine ◽  
Two Stage ◽  
Nearest Neighbor Algorithm ◽  
Blade Row ◽  
Unsteady Simulation

The harmonic balance method is a mixed time domain and frequency domain approach for efficiently solving periodic unsteady flows. The implementation described in this paper is designed to efficiently handle the multiple frequencies that arise within a multistage turbomachine due to differing blade counts in each blade row. We present two alternative algorithms that can be used to determine which unique set of frequencies to consider in each blade row. The first, an all blade row algorithm, retains the complete set of frequencies produced by a given blade row’s interaction with all other blade rows. The second, a nearest neighbor algorithm, retains only the dominant frequencies in a given blade row that arise from direct interaction with the adjacent rows. A comparison of results from a multiple blade row simulation based on these two approaches is presented. We will demonstrate that unsteady blade row interactions are accurately captured with the reduced frequency set of the nearest neighbor algorithm, and at a lower computational cost compared to the all blade row algorithm. An unsteady simulation of a two-stage, cooled, high pressure turbine cascade is achieved using the present harmonic balance method and the nearest neighbor algorithm. The unsteady results obtained are compared to steady simulation results to demonstrate the value of performing an unsteady analysis. Considering an unsteady flow through a single blade row turbine blade passage, it is further shown that unsteady effects are important even if the objective is to obtain accurate time-averaged integrated values, such as efficiency.

Reliable Rotor Dynamic Design of High-Pressure Compressors Based on Test Rig Data1

2000 ◽  
Vol 123 (4) ◽  
pp. 849-856 ◽  
Author(s):  
N. G. Wagner
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Labyrinth Seal ◽  
Test Results ◽  
Test Rig ◽  
Overall Design ◽  
Comprehensive Test ◽  
Scale Test ◽  
Discharge Pressure ◽  
Rotor Dynamic

The overall design of high-pressure centrifugal compressors is largely influenced by rotordynamic aspects. Rotor instability may restrict operating speed and/or maximum discharge pressure if the destabilizing effects have not been considered accurately during the design phase. A test rig for high pressures has been designed and operated successfully in order to achieve dynamic labyrinth seal coefficients through simulation of original conditions in every aspect. Details are given of the full-scale test rig, which uses active magnetic bearings as a key feature, as well as results from the comprehensive test program. Later on, these results are employed for the design of a compressor for very high pressures, demonstrating the complexity of this design task. Validation of the labyrinth test data and the rotor dynamic analysis is provided by the results from a PTC 10 class I test on a reinjection compressor. During shop testing, this machine has been run with and without swirl brakes and the test results agree very well with the predictions.

Investigation of Turbine Shroud Distortions on the Aerodynamics of a One and One-Half Stage High-Pressure Turbine

2009 ◽  
Author(s):  
Eric A. Crosh ◽  
Charles W. Haldeman ◽  
Michael G. Dunn ◽  
D. Graham Holmes ◽  
Brian E. Mitchell
Keyword(s):  
High Pressure ◽  
Surface Pressure ◽  
Turbo Code ◽  
Traditional Approach ◽  
Single Frequency ◽  
Pressure Measurements ◽  
Pressure Loading ◽  
High Pressure Turbine ◽  
Unsteady Pressure ◽  
Blade Row

As part of a proactive effort to investigate the ability of computational fluid dynamic (CFD) tools to predict time-accurate surface-pressure histories, a combined experimental/computational investigation was performed examining the effect of rotor shroud (casing) out-of-roundness on the unsteady pressure loading for the blade row of a full-stage turbine. The casing out-of-roundness was idealized by designing a casing ring with a sinusoidal variation. This casing ring was used to replace a flat casing for an existing turbine and direct comparisons were made between the time-accurate pressure measurements and predictions obtained using the flat and “wavy” casings. For both casing configurations, predictions of the unsteady pressure loading for many locations on the blade and vane were obtained using Numeca’s FINE/Turbo code and the General Electric TACOMA code. This paper will concentrate on the results obtained for the “wavy” casing, but the results for the flat casing are presented as a baseline case. The time-accurate surface-pressure measurements were acquired for the vane and blade of a modern, 3-D, stage and 1/2 high-pressure turbine operating at the design corrected speed and stage pressure ratio. The research program utilized an un-cooled turbine stage for which all three airfoil rows are heavily instrumented at multiple spans to develop a full dataset. The vane-blade-vane count for this machine is 38-72-38. The number of waves in the distorted shroud “wavy wall” is approximately 1.5-times the number of vanes. The resulting changes in aerodynamic surface-pressure measurements were measurable at all blade span wise locations. Variations in time-average surface pressure of up to 5% of the flat casing values were observed. In addition, the frequency content of the time-resolved blade data for the “wavy” casing changed substantially from that measured using the flat casing, with changes in both amplitudes and frequencies. Imposing the casing irregularity changed the fundamental physics of the problem from a single frequency and its harmonics to a multi-frequency problem with mixed harmonics. The unsteady effects of this type of problem can be addressed using the harmonic method within Numeca’s FINE/Turbo code, which is designed to handle multiple blade passing frequencies and harmonics for one blade row. A more traditional approach is included in the paper by employing the TACOMA code in a linearized mode that produces results for a single frequency. These results show that casing irregularity can have a significant influence on the blade surface-pressure characteristics. Further, it is demonstrated that the FINE/Turbo code experienced difficulty predicting the unsteady pressure signal attributed to the “wavy” casing configuration, while at the same time capturing the unsteady signal attributed to the vane passing due to limitations in the current methodology.

Investigation of Turbine Shroud Distortions on the Aerodynamics of a One and One-Half Stage High-Pressure Turbine

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
Eric A. Crosh ◽  
Charles W. Haldeman ◽  
Michael G. Dunn ◽  
D. Graham Holmes ◽  
Brian E. Mitchell
Keyword(s):  
High Pressure ◽  
Surface Pressure ◽  
Turbo Code ◽  
Single Frequency ◽  
Pressure Measurements ◽  
Pressure Loading ◽  
High Pressure Turbine ◽  
Data Set ◽  
Unsteady Pressure ◽  
Blade Row

As part of a proactive effort to investigate the ability of computational fluid dynamics tools to predict time-accurate surface-pressure histories, a combined experimental/computational investigation was performed, examining the effect of rotor shroud (casing) out-of-roundness on the unsteady pressure loading for the blade row of a full-stage turbine. The casing out-of-roundness was idealized by designing a casing ring with a sinusoidal variation. This casing ring was used to replace a flat casing for an existing turbine, and direct comparisons were made between the time-accurate pressure measurements and predictions obtained using the flat and “wavy” casings. For both casing configurations, predictions of the unsteady pressure loading for many locations on the blade and vane were obtained using Numeca’s FINE/TURBO code and General Electric’s turbine and compressor analysis (TACOMA) code. This paper will concentrate on the results obtained for the wavy casing, but the results for the flat casing are presented as a baseline case. The time-accurate surface-pressure measurements were acquired for the vane and blade of a modern, 3D, 1 and 1/2 stage high-pressure turbine operating at the design corrected speed and stage pressure ratio. The research program utilized an uncooled turbine stage for which all three airfoil rows are heavily instrumented at multiple spans to develop a full data set. The vane-blade-vane count for this machine is 38-72-38. The number of waves in the distorted shroud “wavy wall” is approximately 1.5 times the number of vanes. The resulting changes in the aerodynamic surface-pressure measurements were measurable at all blade spanwise locations. Variations in the time-averaged surface pressure of up to 5% of the flat casing values were observed. In addition, the frequency content of the time-resolved blade data for the wavy casing changed substantially from that measured using the flat casing, with changes in both amplitudes and frequencies. Imposing the casing irregularity changed the fundamental physics of the problem from a single frequency and its harmonics to a multifrequency problem with mixed harmonics. The unsteady effects of this type of problem can be addressed using the harmonic method within Numeca’s FINE/TURBO code, which is designed to handle multiple blade passing frequencies and harmonics for one blade row. A more traditional approach is included in this paper by employing the TACOMA code in a linearized mode that produces results for a single frequency. These results show that casing irregularity can have a significant influence on the blade surface-pressure characteristics. Further, it is demonstrated that the FINE/TURBO code experienced difficulty in predicting the unsteady pressure signal attributed to the wavy casing configuration, while at the same time, in capturing the unsteady signal attributed to the vane passing due to limitations in the current methodology.

Aerodynamics and Heat Transfer for a Cooled One and One-Half Stage High-Pressure Turbine: Part III—Impact of Hot Streak Characteristics on Blade Row Heat Flux

2010 ◽  
Author(s):  
R. M. Mathison ◽  
C. W. Haldeman ◽  
M. G. Dunn
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
Radial Profile ◽  
Leading Edge ◽  
Coolant Temperature ◽  
High Pressure Turbine ◽  
Blade Row ◽  
Hot Streak ◽  
The Impact

The influence of hot streak magnitude and alignment relative to the vane leading edge on blade row heat flux are investigated for a one and one-half stage high-pressure turbine with a film-cooled vane, purge cooling, and un-cooled blades. The full-stage turbine is operated at design-corrected conditions. In addition to investigating the impact of different hot-streak characteristics, this study also looks at the interaction of cooling flow with the hot streaks. This paper builds on the investigation of profile migration utilizing temperature measurements presented in Part I and the heat transfer measurements presented in Part II. Hot streaks aligned with the vane mid-pitch have a greater impact on blade temperatures and heat-flux values than hot streaks aligned with the vane leading edge. The leading edge hot streaks tend to be mixed out over the surface of the vane. The magnitude of the hot streak is observed to have the largest influence on the temperature and heat flux for the downstream blade. Time-accurate measurements confirm these conclusions and indicate that further analysis of the time-accurate data is warranted. Film cooling is found to impact a hot streak profile in a way similar to that observed for a radial profile. Differences in core to coolant temperature ratio cause the uniform profile to show different coolant effects, but the overall spread of the cooling appears similar.

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