Detailed parametric study of film-cooling effectiveness was carried out on a turbine blade platform of a five-blade linear cascade. The parameters chosen were freestream turbulence intensity, upstream stator-rotor purge flow rate, discrete-hole film-cooling blowing ratio, and coolant-to-mainstream density ratio. The measurement technique adopted was temperature sensitive paint (TSP) technique. Two turbulence intensities of 4.2% and 10.5%; three purge flows between the range of 0.25% and 0.75% of mainstream flow rate; three blowing ratios between 1.0 and 1.8; and three density ratios between 1.1 and 2.2 were investigated. Purge flow was supplied via a typical double-toothed stator-rotor seal, whereas the discrete-hole film-cooling was accomplished via two rows of cylindrical holes arranged along the length of the platform. The inlet and the exit Mach numbers were 0.27 and 0.44, respectively. Reynolds number of the mainstream flow was 7.5 * 105 based on the exit velocity and chord length of the blade. Results indicated that platform film-cooling effectiveness decreased with turbulence intensity, increased with purge flow rate and density ratio, and possessed an optimum blowing ratio value.

References

References
1.
Langston
,
L. S.
, 2001, “
Secondary Flows in Axial Turbines—A Review
,”
Ann. N. Y. Acad. Sci.
,
934
, pp.
11
26
.
2.
Langston
,
L. S.
,
Nice
,
L. M.
, and
Hooper
,
R. M.
, 1976, “
Three-Dimensional Flow Within a Turbine Cascade Passage
,” ASME Paper No. 76-GT-50.
3.
Langston
,
L. S.
, 1980, “
Crossflows in a Turbine Cascade Passage
,”
ASME J. Eng. Power
,
102
, pp.
866
874
.
4.
Chyu
,
M. K.
, 2001, “
Heat Transfer Near Turbine Nozzle Endwall
,”
Ann. N. Y. Acad. Sci.
,
934
, pp.
27
36
.
5.
Simon
,
T. W.
, and
Piggush
,
J. D.
, 2006, “
Turbine Endwall Aerodynamics and Heat Transfer
,”
AIAA J. Propul. Power
,
22
, pp.
310
312
.
6.
Takeishi
,
K.
,
Matsuura
,
M.
,
Aoki
,
S.
, and
Sato
,
T.
, 1990, “
An Experimental Study of Heat Transfer and Film Cooling on Low Aspect Ratio Turbine Nozzles
,”
ASME J. Turbomach.
,
112
, pp.
488
496
.
7.
Harasgama
,
S. P.
, and
Burton
,
C. S.
, 1992, “
Film Cooling Research on the Endwall of a Turbine Nozzle Guide Vane in a Short Duration Annular Cascade: Part 1—Experimental Technique and Results
,”
ASME J. Turbomach.
,
114
, pp.
734
740
.
8.
Jabbari
,
M. Y.
,
Marston
,
K. C.
,
Eckert
,
E. R. G.
, and
Goldstein
,
R. J.
, 1996, “
Film Cooling of the Gas Turbine Endwall by Discrete-Hole Injection
,”
ASME J. Turbomach.
,
118
, pp.
278
284
.
9.
Friedrichs
,
S.
,
Hodson
,
H. P.
, and
Dawes
,
W. N.
, 1996, “
Distribution of Film-Cooling Effectiveness on a Turbine Endwall Measured Using the Ammonia and Diazo Technique
,”
ASME J. Turbomach.
,
118
, pp.
613
621
.
10.
Friedrichs
,
S.
,
Hodson
,
H. P.
, and
Dawes
,
W. N.
, 1997, “
Aerodynamic Aspects of Endwall Film Cooling
,”
ASME J. Turbomach.
,
119
, pp.
786
793
.
11.
Friedrichs
,
S.
,
Hodson
,
H. P.
, and
Dawes
,
W. N.
, 1998, “
The Design of an Improved Endwall Film Cooling Configuration
,” ASME Paper No. 98-GT-483.
12.
Blair
,
M. F.
, 1974, “
An Experimental Study of Heat Transfer and Film Cooling on Large-Scale Turbine Endwall
,”
ASME J. Heat Transfer
,
96
, pp.
524
529
.
13.
Granser
,
D.
, and
Schulenberg
,
T.
, 1990, “
Prediction and Measurement of Film Cooling Effectiveness for a First-Stage Turbine Vane Shroud
,” ASME Paper No. 90-GT-95.
14.
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.
15.
Burd
,
S. W.
,
Satterness
,
C. J.
, and
Simon
,
T. J.
, 2000, “
Effects of Slot Bleed Injection Over a Contoured End Wall on Nozzle Guide Vane Cooling Performance: Part II—Thermal Measurements
,” ASME Paper No. 2000-GT-200.
16.
Oke
,
R.
,
Simon
,
T.
,
Shih
,
T.
,
Zhu
,
B.
,
Lin
,
Y. L.
, and
Chyu
,
M.
, 2001, “
Measurements Over a Film-Cooled Contoured Endwall With Various Coolant Injection Rates
,” ASME Paper No. 2001-GT-0140.
17.
Oke
,
R. A.
, and
Simon
,
T. W.
, 2002, “
Film Cooling Experiments With Flow Introduced Upstream of a First Stage Nozzle Guide Vane through Slots of Various Geometries
,” ASME Paper No. GT-2002-30169.
18.
Zhang
,
L. J.
, and
Jaiswal
,
R. S.
, 2001, “
Turbine Nozzle Endwall Film Cooling Study Using Pressure-Sensitive Paint
,”
ASME J. Turbomach.
,
123
, pp.
730
735
.
19.
Zhang
,
L. J.
, and
Moon
,
H. K.
, 2003, “
Turbine Nozzle Endwall Inlet Film Cooling—The Effect of a Backward Facing Step
,” ASME Paper No. GT2003-38319.
20.
Wright
,
L. M.
,
Blake
,
S.
,
Rhee
,
D. H.
, and
Han
,
J. C.
, 2007, “
Effect of Upstream Wake With Vortex on Turbine Blade Platform Film Cooling With Simulated Stator-Rotor Purge Flow
,” ASME Paper No. GT2007-27092.
21.
Gao
,
Z.
,
Narzary
,
D.
,
Mhetras
,
S.
, and
Han
,
J. C.
, 2007, “
Upstream Vortex Effect on Turbine Blade Platform Film Cooling With Typical Stator-Rotor Purge Flow
,” ASME Paper No. IMECE2007-41717.
22.
Suryanarayanan
,
A.
,
Ozturk
,
B.
,
Schobeiri
,
M. T.
, and
Han
,
J. C.
, 2007, “
Film Cooling Effectiveness on a Rotating Turbine Platform Using Pressure Sensitive Paint Technique
,” ASME Paper No. GT2007-27122.
23.
Nicklas
,
M.
, 2001, “
Film-Cooled Turbine Endwall in a Transonic Flow Field: Part II—Heat Transfer and Film Cooling Effectiveness
,”
ASME J. Turbomach.
,
123
, pp.
720
729
.
24.
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.
25.
Gao
,
Z.
,
Narzary
,
D.
, and
Han
,
J. C.
, 2008, “
Turbine Blade Platform Film-Cooling With Typical Stator-Rotor Purge Flow and Discrete-Hole Film Cooling
,” ASME Paper No. GT2008-50286.
26.
Suryanarayanan
,
A.
,
Mhetras
,
S. P.
,
Schobeiri
,
M. T.
, and
Han
,
J. C.
, 2006, “
Film Cooling Effectiveness on a Rotating Blade Platform
,” ASME Paper No. GT2006-90034.
27.
Wright
,
L. M.
,
Blake
,
S.
, and
Han
,
J. C.
, 2006, “
Effectiveness Distributions on Turbine Blade Cascade Platforms Through Simulated Stator-Rotor Seals
,” AIAA Paper No. AIAA-2006-3402.
28.
Pederson
,
D. R.
,
Eckert
,
E. R. G.
, and
Goldstein
,
R. J.
, 1988, “
Film Cooling With Large Density Differences Between the Mainstream and the Secondary Fluid Measured by the Heat-Mass Transfer Analogy
,”
ASME J. Heat Transfer
,
99
, pp.
620
627
.
29.
Sinha
,
A. K.
,
Bogard
,
D. G.
, and
Crawford
,
M. E.
, 1991, “
Film Cooling Effectiveness Downstream of a Single Row of Holes With Variable Density Ratio
,”
ASME J. Turbomach.
,
113
, pp.
442
449
.
30.
Ethridge
,
M. I.
,
Cutbirth
,
J. M.
, and
Bogard
,
D. G.
, 2001, “
Scaling of Performance for Varying Density Ratio Coolants on an Airfoil With Strong Curvature and Pressure Gradient Effects
,”
ASME J. Turbomach.
,
123
, pp.
231
237
.
31.
Ekkad
,
S. V.
,
Mehendale
,
A. B.
,
Han
,
J. C.
, and
Lee
,
C. P.
, 1997, “
Combined Effect of Grid Turbulence and Unsteady Wake on Film Effectiveness and Heat Transfer Coefficient of a Gas Turbine Blade With Air and CO2 Film Injection
,”
ASME J. Turbomach.
,
119
, pp.
594
600
.
32.
Kadotani
,
K.
, and
Goldstein
,
R. J.
, 1979, “
On the Nature of Jets Entering a Turbulent Flow Part A—Jet-Mainstream Interaction
,”
ASME J. Turbomach.
,
101
, pp.
459
465
.
33.
Jumper
,
G. W.
,
Elrod
,
W. C.
, and
Rivir
,
R. B.
, 1991, “
Film Cooling Effectiveness in High-Turbulence Flow
,”
ASME J. Turbomach.
,
113
, pp.
479
483
.
34.
Bons
,
J. P.
,
MacArthur
,
C. D.
, and
Rivir
,
R. B.
, 1996, “
The Effect of High Freestream Turbulence on Film Cooling Effectiveness
,”
ASME J. Turbomach.
,
118
, pp.
814
825
.
35.
Schmidt
,
D. L.
, and
Bogard
,
D. G.
, 1996, “
Effects of Freestream Turbulence and Surface Roughness on Film Cooling
,” ASME Paper No. 96-GT-462.
36.
Burd
,
S. W.
,
Kaszeta
,
R. W.
, and
Simon
,
T. W.
, 1998, “
Measurements in Film Cooling Flows: Hole L/D and Turbulence Intensity Effects
,”
ASME J. Turbomach.
,
120
, pp.
791
798
.
37.
Baines
,
W. G.
, and
Peterson
,
E. G.
, 1951, “
An Investigation of Flow through Screens
,”
Trans. ASME
,
73
, pp.
467
480
.
38.
Saumweber
,
C.
,
Schulz
,
A.
, and
Wittig
,
S.
, 2003, “
Free-Stream Turbulence Effects on Film Cooling With Shaped Holes
,”
ASME J. Turbomach.
,
125
, pp.
65
73
.
39.
Coleman
,
H. W.
, and
Steele
,
W. G.
, 1989,
Experimentation and Uncertainty Analysis for Engineers
,
John Wiley & Sons
,
New York
.
You do not currently have access to this content.