Abstract

In this paper, we present the evaluation of the aerodynamic robustness to rim seal purge flow of an optimized 1.5-stage axial turbine configuration with a bowed stator profile and endwall contouring. Performance maps obtained by experiments and numerical simulations show that the efficiency benefit gained by this optimized configuration is partially reduced, but not eliminated, by the injection of purge flow through the cavity downstream of the first stator. Measurements with five-hole probes and hot-wire probes, as well as unsteady RANS simulations, give detailed insights into the physical effects of the purge flow inside the rotor passage. There, when no purge flow is injected, the optimized configuration diminishes the formation of loss-inducing secondary flow structures near the hub and the casing. When purge flow is injected, however, new strong secondary flow structures are induced near the hub. These vortices generate additional losses and thereby partially negate the efficiency benefits gained by the optimization. From the data, we found that this influence of the purge flow is limited to the lower half of the channel height. The data also show that the optimized configuration is able to reduce the vorticity near the casing regardless of the purge flow injection, which in turn leads to an efficiency increase in this area. Together, these effects lead to a reduction of the previously gained efficiency benefit by the optimized configuration when it is subjected to purge flow injection. However, compared to a baseline configuration with cylindrical endwalls also subject to purge flow injection, the overall efficiency is still increased by 0.38%.

References

1.
Rose
,
M. G.
,
1994
, “
Non-Axisymmetric Endwall Profiling in the HP NGV’s of an Axial Flow Gas Turbine
,”
Proceedings of the ASME 1994 International Gas Turbine and Aeroengine Congress and Exposition
,
The Hague, The Netherlands
,
June 13–16
, ASME Paper No. 94-GT-249.
2.
Hartland
,
J. C.
,
Gregory-Smith
,
D. G.
, and
Rose
,
M. G.
,
1998
, “
Non-Axisymmetric Endwall Profiling in a Turbine Rotor Blade
,”
Proceedings of the ASME 1998 International Gas Turbine and Aeroengine Congress and Exhibition. Volume 1: Turbomachinery
,
Stockholm, Sweden
,
June 2–5
, ASME Paper No. 98-GT-525.
3.
Brennan
,
G.
,
Harvey
,
N. W.
,
Rose
,
M. G.
,
Fomison
,
N.
, and
Taylor
,
M. D.
,
2001
, “
Improving the Efficiency of the Trent 500 HP Turbine Using Non-Axisymmetric End Walls: Part 1—Turbine Design
,”
Proceedings of the ASME Turbo Expo 2001: Power for Land, Sea, and Air. Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery
,
New Orleans, LA
,
June 4–7
, ASME Paper No. 2001-GT-0444.
4.
Rose
,
M. G.
,
Harvey
,
N. W.
,
Seaman
,
P.
,
Newman
,
D. A.
, and
McManus
,
D.
,
2001
, “
Improving the Efficiency of the Trent 500 HP Turbine Using Non-Axisymmetric End Walls: Part II—Experimental Validation
,”
Proceedings of the ASME Turbo Expo 2001: Power for Land, Sea, and Air. Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery
,
New Orleans, LA
,
June 4–7
, ASME Paper No. 2001-GT-0505.
5.
Harvey
,
N. W.
,
Brennan
,
G.
,
Newman
,
D. A.
, and
Rose
,
M. G.
,
2002
, “
Improving Turbine Efficiency Using Non-Axisymmetric End Walls: Validation in the Multi-Row Environment and With Low Aspect Ratio Blading
,”
Proceedings of the ASME Turbo Expo 2002: Power for Land, Sea, and Air. Volume 5: Turbo Expo 2002, Parts A and B
,
Amsterdam, The Netherlands
,
June 3–6
, ASME Paper No. GT2002-30337.
6.
Snedden
,
G.
,
Dunn
,
D.
,
Ingram
,
G.
, and
Gregory-Smith
,
D.
,
2010
, “
The Performance of a Generic Non-Axisymmetric End Wall in a Single Stage, Rotating Turbine at On and Off-Design Conditions
,”
Proceedings of the ASME Turbo Expo 2010: Power for Land, Sea, and Air. Volume 7: Turbomachinery, Parts A, B, and C
,
Glasgow, UK
,
June 14–18
, ASME Paper No. GT2010-22006.
7.
Germain
,
T.
,
Nagel
,
M.
,
Raab
,
I.
,
Schüpbach
,
P.
,
Abhari
,
R. S.
, and
Rose
,
M. G.
,
2010
, “
Improving Efficiency of a High Work Turbine Using Nonaxisymmetric Endwalls—Part I: Endwall Design and Performance
,”
ASME J. Turbomach.
,
132
(
2
), p.
021007
.
8.
Poehler
,
T.
,
Niewoehner
,
J.
,
Jeschke
,
P.
, and
Guendogdu
,
Y.
,
2015
, “
Investigation of Nonaxisymmetric Endwall Contouring and Three-Dimensional Airfoil Design in a 1.5-Stage Axial Turbine—Part I: Design and Novel Numerical Analysis Method
,”
ASME J. Turbomach.
,
137
(
8
), p.
081009
.
9.
Niewoehner
,
J.
,
Poehler
,
T.
,
Jeschke
,
P.
, and
Guendogdu
,
Y.
,
2015
, “
Investigation of Nonaxisymmetric Endwall Contouring and Three-Dimensional Airfoil Design in a 1.5 Stage Axial Turbine—Part II: Experimental Validation
,”
ASME J. Turbomach.
,
137
(
8
), p.
081010
.
10.
Denton
,
J. D.
,
1993
, “
Loss Mechanisms in Turbomachines
,”
Proceedings of the ASME 1993 International Gas Turbine and Aeroengine Congress and Exposition. Volume 2: Combustion and Fuels; Oil and Gas Applications; Cycle Innovations; Heat Transfer; Electric Power; Industrial and Cogeneration; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation
,
Cincinnati, OH
,
May 24–27
, ASME Paper No. 93-GT-435.
11.
McLean
,
C.
,
Camci
,
C.
, and
Glezer
,
B.
,
2001
, “
Mainstream Aerodynamic Effects Due to Wheelspace Coolant Injection in a High-Pressure Turbine Stage: Part I—Aerodynamic Measurements in the Stationary Frame
,”
ASME J. Turbomach.
,
123
(
4
), pp.
687
696
.
12.
Mclean
,
C.
,
Camci
,
C.
, and
Glezer
,
B.
,
2001
, “
Mainstream Aerodynamic Effects Due to Wheelspace Coolant Injection in a High-Pressure Turbine Stage: Part II—Aerodynamic Measurements in the Rotational Frame
,”
ASME Turbo Expo 2001: Power for Land, Sea, and Air
,
New Orleans, LA
,
June 4–7
, ASME Paper No. 2001-GT-0120.
13.
Hunter
,
S. D.
, and
Manwaring
,
S. R.
,
2000
, “
Endwall Cavity Flow Effects on Gaspath Aerodynamics in an Axial Flow Turbine: Part I—Experimental and Numerical Investigation
,”
Proceedings of the ASME Turbo Expo 2000: Power for Land, Sea, and Air. Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery
,
Munich, Germany
,
May 8–11
, ASME Paper No. 2000-GT-0651.
14.
Ong
,
J.
,
Miller
,
R. J.
, and
Uchida
,
S.
,
2012
, “
The Effect of Coolant Injection on the Endwall Flow of a High Pressure Turbine
,”
ASME J. Turbomach.
,
134
(
5
), p.
051003
.
15.
Reid
,
K.
,
Denton
,
J.
,
Pullan
,
G.
,
Curtis
,
E.
, and
Longley
,
J.
,
2006
, “
The Effect of Stator-Rotor Hub Sealing Flow on the Mainstream Aerodynamics of a Turbine
,”
Proceedings of the ASME Turbo Expo 2006: Power for Land, Sea, and Air. Volume 6: Turbomachinery, Parts A and B
,
Barcelona, Spain
,
May 8–11
, ASME Paper No. GT2006-90838.
16.
Schüpbach
,
P.
,
Abhari
,
R. S.
,
Rose
,
M. G.
,
Germain
,
T.
,
Raab
,
I.
, and
Gier
,
J.
,
2010
, “
Effects of Suction and Injection Purge-Flow on the Secondary Flow Structures of a High-Work Turbine
,”
ASME J. Turbomach.
,
132
(
2
), p.
021021
.
17.
Dahlqvist
,
J.
, and
Fridh
,
J.
,
2018
, “
Experimental Investigation of Turbine Stage Flow Field and Performance at Varying Cavity Purge Rates and Operating Speeds
,”
ASME J. Turbomach.
,
140
(
3
), p.
031001
.
18.
Regina
,
K.
,
Abhari
,
R.
, and
Kalfas
,
A.
,
2013
, “
Sensitivity of Purge Flow Effects to Different High Work Turbine Designs
,”
XXI International Symposium on Air Breathing Engines (ISABE 2013)
,
Busan, South Korea
,
Sept. 9–13
.
19.
Schüpbach
,
P.
,
Abhari
,
R. S.
,
Rose
,
M. G.
, and
Gier
,
J.
,
2009
, “
Influence of Rim Seal Purge Flow on Performance of an Endwall-Profiled Axial Turbine
,”
ASME J. Turbomach.
,
133
(
2
), p.
021011
.
20.
Regina
,
K.
,
Kalfas
,
A. I.
,
Abhari
,
R. S.
,
Lohaus
,
A.
,
Voelker
,
S.
, and
auf dem Kampe
,
T.
,
2014
, “
Aerodynamic Robustness of End Wall Contouring Against Rim Seal Purge Flow
,”
Proceedings of ASME Turbo Expo 2014: Turbine Technical Conference and Exposition
,
Düsseldorf, Germany
,
June 16–20
, ASME Paper No. GT2014-26007.
21.
Jenny
,
P.
,
Abhari
,
R. S.
,
Rose
,
M. G.
,
Brettschneider
,
M.
, and
Gier
,
J.
,
2012
, “
A Low Pressure Turbine With Profiled Endwalls and Purge Flow Operating With a Pressure Side Bubble
,”
ASME J. Turbomach.
,
134
(
6
), p.
061038
.
22.
Halstead
,
D. E.
,
Wisler
,
D. C.
,
Okiishi
,
T. H.
,
Walker
,
G. J.
,
Hodson
,
H. P.
, and
Shin
,
H.-W.
,
1997
, “
Boundary Layer Development in Axial Compressors and Turbines: Part 1 of 4—Composite Picture
,”
ASME J. Turbomach.
,
134
(
6
), pp.
114
127
.
23.
Restemeier
,
M.
,
Jeschke
,
P.
,
Guendogdu
,
Y.
, and
Gier
,
J.
,
2013
, “
Numerical and Experimental Analysis of the Effect of Variable Blade Row Spacing in a Subsonic Axial Turbine
,”
ASME J. Turbomach.
,
135
(
2
), p.
021031
.
24.
Niewöhner
,
J.
,
2017
,
Wirkungsgradpotential von nicht-rotationssymmetrischen Seitenwandstrukturen und Schaufelneigung in einer subsonischen Axialturbine
,
Verlag Dr. Hut
,
München
.
25.
Parvizinia
,
M.
, and
Salchow
,
K.
,
1993
, “
Verfahren zur Korrektur des Gradientenfehlers bei Messungen mit pneumatischen Mehrlochsonden
,”
Technical Report TM93-10
,
Institute of Jet Propulsion and Turbomachinery, RWTH Aachen University
,
Aachen, Germany
.
26.
Bruun
,
H. H.
,
1996
,
Hot-Wire Anemometry: Principles and Signal Analysis
,
Oxford University Press
,
Oxford
.
27.
Hösgen
,
C.
,
Behre
,
S.
,
Hönen
,
H.
, and
Jeschke
,
P.
,
2016
, “
Analytical Uncertainty Analysis for Hot-Wire Measurements
,”
Proceedings of ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition
,
Seoul, South Korea
,
June 13–17
, ASME Paper No. GT2016-56623.
28.
Menter
,
F.
,
Kuntz
,
M.
, and
Langtry
,
R.
,
2003
, “
Ten Years of Industrial Experience With the SST Model
,”
Turbulence, Heat Mass Transf.
,
4
(
1
), pp.
625
632
.
29.
Kato
,
M.
, and
Launder
,
B. E.
,
1993
, “
The Modeling of Turbulent Flow Around Stationary and Vibrating Square Cylinders
,”
Proceedings of the 9th Symposium on Turbulent Shear Flows
,
Kyoto, Japan
,
Aug. 16–18
.
30.
Bardina
,
J.
,
Ferziger
,
J. H.
, and
Rogallo
,
R. S.
,
1985
, “
Effect of Rotation on Isotropic Turbulence
,”
J. Fluid Mech.
,
154
, pp.
321
336
.
31.
Röber
,
T.
,
Kožulović
,
D.
,
Kügeler
,
E.
, and
Nürnberger
,
D.
,
2006
, “
Appropriate Turbulence Modelling for Turbomachinery Flows Using a Two-Equation Turbulence Model
,”
New Results in Numerical and Experimental Fluid Mechanics V. Notes on Numerical Fluid Mechanics and Multidisciplinary Design
,
H.-J.
Rath
,
C.
Holze
,
H.-J.
Heinemann
,
R.
Henke
, and
H.
Hönlinger
, eds.,
Springer
,
Berlin/Heidelberg
,
92
(
1
), pp.
446
454
.
32.
Kožulović
,
D.
,
2007
,
Modellierung des Grenzschichtumschlags bei Turbomaschinenströmungen unter Berücksichtigungen mehrerer Umschlagsarten
,
Ruhr-Universität Bochum
,
Bochum
.
33.
Walraevens
,
R. E.
,
2000
,
Experimentelle Analyse dreidimensionaler instationärer Strömungseffekte in einer 1 1/2-stufigen Axialturbine
,
Verlag Dr. Hut
,
München
.
34.
Niehuis
,
R.
,
Lücking
,
P.
, and
Stubert
,
B.
,
1989
, “
Experimental and Numerical Study on Basic Phenomena of Secondary Flows in Turbines
,”
AGARD Conference Proceedings
,
Luxembourg
,
Aug. 30–Sept. 1
.
35.
Stephan
,
B.
,
Gallus
,
H. E.
, and
Niehuis
,
R.
Turbinenlaufrad/-leitradströmung II—Experimentelle Untersuchung der Turbinenleitradströmung unter Variation des Radialspaltes des vorgeschalteten Laufrades
,”
Abschlussbericht Vorhaben 654, Heft 690, Forschungsvereinigung Verbrennungskraftmaschinen e.V. FVV
,
2000
.
36.
Jeong
,
J.
, and
Hussain
,
F.
,
1995
, “
On the Identification of a Vortex
,”
J. Fluid Mech.
,
285
(
1
), pp.
69
94
.
37.
Jenny
,
P.
,
Abhari
,
R. S. R. M. G.
,
Brettschneider
,
M.
,
Engel
,
K.
, and
Gier
,
J.
,
2013
, “
Unsteady Rotor Hub Passage Vortex Behavior in the Presence of Purge Flow in Axial Low Pressure Turbine
,”
ASME J. Turbomach.
,
135
(
5
), p.
051022
.
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