This paper describes experimental and numerical investigations of a highly-loaded rotor blade with leakage (purge) flow injection through an upstream overlapping seal. The effects of both leakage mass flow rates and swirl have been studied to examine their effects on the aerothermal performance. As the leakage mass flow rate was increased, the loss generally increased. The increase in the losses was found to be nonlinear with the three distinct regimes of leakage-mainstream interaction being identified. The varying sensitivity of the losses to the leakage fraction was linked to the effects of the upstream potential field of the blade on a vortical structure originating from the outer part of the seal. This vortical structure affected the interaction between the leakage and mainstream flows as it grew to become the hub passage vortex. Very limited cooling was provided by the leakage flows. The coolant was mainly concentrated close to the suction surface in the front part of the rotor platform and on the blade suction surface in the path of the passage vortex. However, the regions benefiting from cooling were also characterized by higher values of the heat transfer coefficient. As a consequence, the net heat flux reduction was small, and the leakage injection was thus deemed thermally neutral.

References

References
1.
Wang
,
C. Z.
,
de Jong
,
F.
,
Johnson
,
B. V.
, and
Vashist
,
T. K.
,
2007
, “
Comparison of Flow Characteristics in Axial-Gap Seals for Close- and Wide-Spaced Turbine Stages
,”
ASME
Paper No. GT2007-27909.10.1115/GT2007-27909
2.
Bunker
,
R.
,
Metzger
,
D.
, and
Wittig
,
S.
,
1992
, “
Local Heat Transfer in Turbine Disk Cavities: Part I—Rotor and Stator Cooling With Hub Injection of Coolant
,”
ASME J. Turbomach.
,
114
, pp.
211
220
.10.1115/1.2927988
3.
Bunker
,
R.
,
Metzger
,
D.
, and
Wittig
,
S.
,
1992
, “
Local Heat Transfer in Turbine Disk Cavities: Part II—Rotor Cooling With Radial Location Injection of Coolant
,”
ASME J. Turbomach.
,
114
, pp.
221
228
.10.1115/1.2927989
4.
Owen.
J. M.
, and
Wilson
,
M.
,
2001
, “
Some Current Research in Rotating Disc Systems
,”
Ann. N.Y. Acad. Sci.
,
934
, pp.
206
221
.10.1111/j.1749-6632.2001.tb05853.x
5.
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
, pp.
687
696
.10.1115/1.1401026
6.
Girgis
,
S.
,
Vlasic
,
E.
,
Lavole
,
J.-P.
, and
Moustapha
,
S. H.
,
2002
, “
The Effect of Secondary Air Injection on the Performance of a Transonic Turbine Stage
,”
ASME
Paper No. GT2002-30340.10.1115/GT2002-30340
7.
de la Rosa Blanco
,
E.
,
Hodson
H. P.
, and
Vazques
,
R.
,
2006
, “
Effect of the Leakage Flows and the Upstream Platform Geometry on the Endwall Flows of a Turbine Cascade
,”
ASME
Paper No. GT2006-90767.10.1115/GT2006-90767
8.
Reid
,
K.
,
Denton
,
J.
,
Pullan
,
G.
,
Curtis
,
E.
, and
Longley
,
J.
,
2006
, “
The Effect of Staor-Rotor Hub Sealing Flow on the Mainstream Aerodynamics of a Turbine
,”
ASME
Paper No. GT2006-90838.10.1115/GT2006-90838
9.
Roy
,
R. P.
,
Squires
,
K. D.
,
Gerendas
,
M.
,
Song
,
S.
,
Howe
,
W. J.
, and
Ansari
,
A.
,
2000
, “
Flow and Heat Transfer at the Hub Endwall of Inlet Vane Passages—Experiments and Simulations
,” ASME Paper No. 2000-GT-198.
10.
Burd
,
S. W.
,
Satterness
,
C. J.
, and
Simon
,
T. W.
,
2000
, “
Effects of Slot Bleed Injection Over a Contoured Endwall on Nozzle Guide Vane Cooling Performance: Part II—Thermal Measurements
,” ASME Paper No. 2000-GT-200.
11.
Lynch
,
S. P.
, and
Thole
,
K. A.
,
2007
, “
The Effect of Combustor-Turbine Interface Gap Leakage on the Endwall Heat Transfer for a Nozzle Guide Vane
,”
ASME
Paper No. GT2007-27867.10.1115/GT2007-27867
12.
Dannhauer
,
A.
,
2008
, “
Analysis of Cooling Effectiveness and Heat Transfer Variations on the Endwall of a Nozzle Guide Vane Caused by Turbine Leakage Flows
,”
ASME
Paper No. GT2008-50555.10.1115/GT2008-50555
13.
Dénos
,
R.
, and
Paniagua
,
G.
,
2002
, “
Influence of the Hub Endwall Cavity Flow on the Time-Averaged and Time-Resolved Aero-Thermodynamics of Axial HP Turbine Stage
,”
ASME
Paper No. GT2002-30185.10.1115/GT2002-30185
14.
Wright
,
L. M.
,
Gao
,
Z.
,
Yang
,
H.
, and
Han
,
J. C.
,
2006
, “
Film Cooling Effectiveness Distribution on a Gas Turbine Blade Platform With Inclined Slot Leakage and Discrete Film Hole Flows
,”
ASME
Paper No. GT2006-90375.10.1115/GT2006-90375
15.
Mirzamoghadam
,
A. V.
,
Heitland
,
G.
,
Morris
,
M. C.
,
Smoke
,
J.
,
Malak
,
M.
, and
Howe
,
J.
,
2008
, “
3D CFD Ingestion Evaluation of a High Pressure Turbine Rim Seal Disk Cavity
,”
ASME
Paper No. GT2008-50531.10.1115/GT2008-50531
16.
Zorić
,
T.
,
Popović
,
I.
,
Sjolander
,
S. A.
,
Praisner
,
T.
, and
Grover
,
E.
,
2007
, “
Comparative Investigation of Three Highly Loaded LP Turbine Airfoils: Part I—Measured Profile And Secondary Losses At Design Incidence
,”
ASME
Paper No. GT2007-27537.10.1115/GT2007-27537
17.
Radomsky
,
R. W.
, and
Thole
,
K. A.
,
2000
, “
High Freestream Turbulence Effects on Endwall Heat Transfer for a Gas Turbine Stator Vane
,” ASME Paper No. 2000-GT-0201.
18.
Amecke
,
J.
,
1967
, “
Auswertung von Nachlaufmessungen an Ebenen Schaufelgittern
,” AVA Göttingen, Report No. 67A 49.
19.
Sen
,
B.
,
Schmidt
,
D. L.
, and
Bogard
,
D. G.
,
1996
, “
Film Cooling With Compound Angle Holes: Heat Transfer
,”
ASME J. Turbomach.
,
118
, pp.
800
806
.10.1115/1.2840937
20.
Denton
,
J. D.
, 1993, “
Loss Mechanisms in Turbomachinery
,”
ASME J. Turbomach.
,
115
, pp.
621
656
.10.1115/1.2929299
21.
Rosić
,
B.
,
Denton
,
J. D.
, and
Curtis
,
E. M.
,
2008
, “
The Influence of Shroud and Cavity Geomtry on Turbine Performance: An Experimental and Computational Study—Part 1: Shroud Geometry
,”
ASME J. Turbomach.
,
130
, p.
041001
.10.1115/1.2777201
You do not currently have access to this content.