In the present paper, an experimental investigation of the effects of rim seal purge flow on the performance of a highly loaded axial turbine stage is presented. The test configuration consists of a one-and-a-half stage, unshrouded, turbine, with a blading representative of high pressure (HP) gas turbines. Efficiency measurements for various purge flow injection levels have been carried out with pneumatic probes at the exit of the rotor and show a reduction of isentropic total-to-total efficiency of 0.8% per percent of injected mass flow. For three purge flow conditions, the unsteady aerodynamic flow field at rotor inlet and rotor exit has been measured with the in-house developed fast response aerodynamic probe (FRAP). The time-resolved data show the unsteady interaction of the purge flow with the secondary flows of the main flow and the impact on the radial displacement of the rotor hub passage vortex (HPV). Steady measurements at off-design conditions show the impact of the rotor incidence and of the stage flow factor on the resulting stage efficiency and the radial displacement of the rotor HPV. A comparison of the effect of purge flow and of the off-design conditions on the rotor incidence and stage flow factor shows that the detrimental effect of the purge flow on the stage efficiency caused by the radial displacement of the rotor HPV is dominated by the increase of stage flow factor in the hub region rather than by the increase of negative rotor incidence.

References

References
1.
Kobayashi
,
N.
,
Matsumato
,
M.
, and
Shizuya
,
M.
,
1984
, “
An Experimental Investigation of a Gas Turbine Disk Cooling System
,”
ASME J. Eng. Gas Turbines Power
,
106
(
1
), pp.
136
141
.10.1115/1.3239525
2.
Chew
,
J. W.
,
Dadkhah
,
S.
, and
Turner
,
A. B.
,
1992
, “
Rim Sealing of Rotor–Stator Wheelspaces in the Absence of External Flow
,”
ASME J. Turbomach.
,
114
(
2
), pp.
433
438
.10.1115/1.2929162
3.
Dadkhah
,
S.
,
Turner
,
A. B.
, and
Chew
,
J. W.
,
1992
, “
Performance of Radial Clearance Rim Seals in Upstream and Downstream Rotor–Stator Wheelspaces
,”
ASME J. Turbomach.
,
114
(
2
), pp.
439
445
.10.1115/1.2929163
4.
Bohn
,
D.
,
Rudzinski
,
B.
,
Sürken
,
N.
, and
Gärtner
,
W.
,
2000
, “
Experimental and Numerical Investigation of the Influence of Rotor Blades on Hot Gas Ingestion Into the Upstream Cavity of an Axial Turbine Stage
,”
ASME
Paper No. 2000-GT-0284.10.1115/2000-GT-0284
5.
Gentilhomme
,
O.
,
Hills
,
N. J.
,
Turner
,
A. B.
, and
Chew
,
J. W.
,
2003
, “
Measurement and Analysis of Ingestion Through a Turbine Rim Seal
,”
ASME J. Turbomach.
,
125
(
3
), pp.
505
512
.10.1115/1.1556411
6.
Bohn
,
D. E.
,
Decker
,
A.
,
Ohlendorf
,
N.
, and
Jakoby
,
R.
,
2006
, “
Influence of an Axial and Radial Rim Seal Geometry on Hot Gas Ingestion Into the Upstream Cavity of a 1.5-Stage Turbine
,”
ASME
Paper No. GT2006-90453.10.1115/GT2006-90453
7.
Jakoby
,
R.
,
Zierer
,
T.
,
Lindblad
,
K.
,
Larsson
,
J.
,
deVito
,
L.
,
Bohn
,
D. E.
,
Funcke
,
J.
, and
Decker
,
A.
,
2004
, “
Numerical Simulation of the Unsteady Flow Field in an Axial Gas Turbine Rim Seal Configuration
,”
ASME
Paper No. GT2004-53829.10.1115/GT2004-53829
8.
Cao
,
C.
,
Chew
,
J. W.
,
Millington
,
P. R.
, and
Hogg
,
S. I.
,
2003
, “
Interaction of Rim Seal and Annulus Flows in an Axial Flow Turbine
,”
ASME
Paper No. GT2003-38368.10.1115/GT2003-38368
9.
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
,”
ASME
Paper No. 2000-GT-0651.10.1115/2000-GT-0651
10.
Schrewe
,
S.
,
Linker
,
C.
,
Krichbaum
,
A.
, and
Schiffer
,
H.-P.
,
2011
, “
Measurements of Rim Seal Mixing Processes in an Axial Two Stage Turbine
,”
20th International Symposiumm on Air Breathing Engines (ISABE 2011)
, Gothenburg, Sweden, Sept. 12–16, Paper No. ISABE-2011-1720.
11.
Jenny
,
P.
,
Abhari
,
R. S.
,
Rose
,
M. G.
,
Brettschneider
,
M.
,
Gier
,
J.
, and
Engel
,
K.
,
2011
, “
Low-Pressure Turbine End Wall Design Optimisation and Experimental Verification in the Presence of Purge Flow
,”
20th International Symposiumm on Air Breathing Engines (ISABE 2011)
, Gothenburg, Sweden, Sept. 12–16, Paper No. ISABE-2011-1717.
12.
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
.10.1115/1.1401026
13.
Paniagua
,
G.
,
Dénos
,
R.
, and
Almeida
,
S.
,
2004
, “
Effect of the Hub Endwall Cavity Flow on the Flow-Field of a Transonic High-Pressure Turbine
,”
ASME J. Turbomach.
,
126
(
4
), pp.
578
586
.10.1115/1.1791644
14.
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
,”
ASME
Paper No. GT2006-90838.10.1115/GT2006-90838
15.
Ong
,
J. H. P.
,
Miller
,
R. J.
, and
Uchida
,
S.
,
2006
, “
The Effect of Coolant Injection on the Endwall Flow of a High Pressure Turbine
,”
ASME
Paper No. GT2006-91060.10.1115/GT2006-91060
16.
Schuepbach
,
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
.10.1115/1.4000485
17.
Schuepbach
,
P.
,
Abhari
,
R. S.
,
Rose
,
M. G.
, and
Gier
,
J.
,
2011
, “
Influence of Rim Seal Purge Flow on the Performance of an Endwall-Profiled Axial Turbine
,”
ASME J. Turbomach.
,
133
(
2
), p.
021011
.10.1115/1.4000578
18.
Behr
,
T.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
,
2007
, “
Unsteady Flow Physics and Performance of a One-and-1/2-Stage Unshrouded High Work Turbine
,”
ASME J. Turbomach.
,
129
(
2
), pp.
348
359
.10.1115/1.2447707
19.
Kupferschmied
,
P.
,
Köppel
,
P.
,
Gizzi
,
W.
,
Roduner
,
C.
, and
Gyarmathy
,
G.
,
2000
, “
Time-Resolved Flow Measurements With Fast-Response Aerodynamic Probes in Turbomachines
,”
Meas. Sci. Technol.
11
(
7
), pp.
1036
1054
.10.1088/0957-0233/11/7/318
20.
Pfau
,
A.
,
Schlienger
,
J.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
,
2003
, “
Unsteady 3-Dimensional Flow Measurement Using a Miniature Virtual 4 Sensor Fast Response Aerodynamic Probe (FRAP)
,”
ASME
Paper No. GT2003-38128.10.1115/GT2003-38128
21.
Porreca
,
L.
,
Hollenstein
,
M.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
,
2007
, “
Turbulence Measurements and Analysis in a Multistage Axial Turbine
,”
J. Propul. Power
,
23
(
1
), pp.
227
234
.10.2514/1.20022
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