In this paper, the transient IR-thermography method is used to investigate the effect of showerhead cooling on the film-cooling performance of the suction side of a turbine guide vane working under engine-representative conditions. The resulting adiabatic film effectiveness, heat transfer coefficient (HTC) augmentation, and net heat flux reduction (NHFR) due to insertion of rows of cooling holes at two different locations in the presence and absence of the showerhead cooling are presented. One row of cooling holes is located in the relatively high convex surface curvature region, while the other is situated closer to the maximum throat velocity. In the latter case, a double staggered row of fan-shaped cooling holes has been considered for cross-comparison with the single row at the same position. Both cylindrical and fan-shaped holes have been examined, where the characteristics of fan-shaped holes are based on design constraints for medium size gas turbines. The blowing rates tested are 0.6, 0.9, and 1.2 for single and double cooling rows, whereas the showerhead blowing is maintained at constant nominal blowing rate. The adiabatic film effectiveness results indicate that most noticable effects from the showerhead can be seen for the cooling row located on the higher convex surface curvature. This observation holds for both cylindrical and fan-shaped holes. These findings suggest that while the showerhead blowing does not have much impact on this cooling row from HTC enhancement perspective, it is influential in determination of the HTC augmentation for the cooling row close to the maximum throat velocity. The double-row fan-shaped cooling seems to be less affected by an upstream showerhead blowing when considering HTC enhancement, but it makes a major contribution in defining adiabatic film effectiveness. The NHFR results highlight the fact that cylindrical holes are not significantly affected by the showerhead cooling regardless of their position, but showerhead blowing can play an important role in determining the overall film-cooling performance of fan-shaped holes (for both the cooling row located on the higher convex surface curvature and the cooling row close to the maximum throat velocity), for both the single and the double row cases.

References

References
1.
Goldstein
,
R. J.
,
Eckert
,
E. R. G.
, and
Ramsey
,
J. W.
,
1968
, “
Film Cooling With Injection Through Holes: Adiabatic Wall Temperature Downstream of a Circular Hole
,”
ASME J. Eng. Power
,
90
(
4
), pp.
384
395
.10.1115/1.3609223
2.
Jabbari
,
M. Y.
, and
Goldstein
,
R. J.
,
1978
, “
Adiabatic Wall Temperature and Heat Transfer Downstream of Injection Through Two Rows of Holes
,”
ASME J. Eng. Power
,
100
(
2
), pp.
303
307
.10.1115/1.3446350
3.
Lee
,
H. W.
,
Park
,
J. J.
, and
Lee
,
J. S.
,
2002
, “
Flow Visualization and Film Cooling Effectiveness Measurements Around Shaped Holes With Compound Angle Orientation
,”
Int. J. Heat Mass Transfer
,
45
(
1
), pp.
145
156
.10.1016/S0017-9310(01)00112-0
4.
Yuen
,
C. H.
, and
Martinez-Botas
,
R. F.
,
2005
, “
Film Cooling Characteristics of Rows of Round Holes at Various Streamwise Angles in a Crossflow: Part I. Film Effectiveness
,”
Int. J. Heat Mass Transfer
,
48
(
23–24
), pp.
4995
5016
.10.1016/j.ijheatmasstransfer.2005.05.019
5.
Polanka
,
M.
,
Witteveld
,
V.
, and
Bogard
,
D. G.
,
1999
, “
Film Cooling Effectiveness in the Showerhead Region of a Gas Turbine Vane: Part I—Stagnation Region and Near-Pressure Side
,”
ASME
Paper No. 99-GT-048.10.1115/99-GT-048
6.
Nasir
,
S.
,
Bolchoz
,
T.
,
Zhang
,
L. J.
,
Anthony
,
R. J.
,
Moon
,
H. K.
, and
Ng
,
W.-F.
,
2012
, “
Showerhead Film Cooling Performance of a Turbine Vane at High Freestream Turbulence in a Transonic Cascade
,”
ASME J. Turbomach.
,
134
(
5
), p.
051021
.10.1115/1.4004200
7.
Sargison
,
J.
,
Guo
,
S.
,
Lock
,
G.
,
Rawlinson
,
A.
, and
Oldfield
,
M.
,
2002
, “
A Converging Slot-Hole Film-Cooling Geometry—Part 2: Transonic Nozzle Guide Vane Heat Transfer and Loss
,”
ASME J. Turbomach.
,
124
(
3
), pp.
461
471
.10.1115/1.1459736
8.
Guo
,
S.
,
Lai
,
C.
,
Jones
,
T.
,
Oldfield
,
M.
,
Lock
,
G.
, and
Rawlinson
,
A.
,
1998
, “
The Application of Thin-Film Technology to Measure Turbine-Vane Heat Transfer and Effectiveness in a Film-Cooled, Engine-Simulated Environment
,”
Int. J. Heat Fluid Flow
,
19
(
6
), pp.
594
600
.10.1016/S0142-727X(98)10034-6
9.
Colban
,
W.
,
Haendler
,
M.
,
Gratton
,
A.
, and
Thole
,
K.
,
2006
, “
Heat Transfer and Film-Cooling Measurements on a Stator Vane With Fan-Shaped Cooling Holes
,”
ASME J. Turbomach.
,
128
(
1
), pp.
53
61
.10.1115/1.2098789
10.
Zhang
,
L.
,
Baltz
,
M.
,
Pudupatty
,
R.
, and
Fox
,
M.
,
1999
, “
Turbine Nozzle Film-Cooling Study Using the Pressure Sensitive Paint (PSP) Technique
,”
ASME
Paper No. 99-GT-196.10.1115/1.1400113
11.
Zhang
,
L.
, and
Pudupatty
,
R.
,
2000
, “
The Effects of Injection Angle and Hole Exit Shape on Turbine Nozzle Pressure Side Film-Cooling
,”
ASME
Paper No. 2000-GT-0247. 10.1115/2000-GT-0247
12.
Nathan
,
M. L.
,
Dyson
,
T. E.
,
Bogard
,
D. G.
, and
Bradshaw
,
S. D.
,
2014
, “
Adiabatic and Overall Effectiveness for the Showerhead Film Cooling of a Turbine Vane
,”
ASME J. Turbomach.
,
136
(
3
), p.
031005
10.1115/1.4024680.
13.
Kinell
,
M.
,
Utriainen
,
E.
,
Najafabadi
,
H. N.
,
Karlsson
,
M.
, and
Barabas
,
B.
,
2012
, “
Comparison of Gas Turbine Vane Pressure Side and Suction Side Film Cooling Performance and the Applicability of Superposition
,”
ASME
Paper No. GT2012-68994. 10.1115/GT2012-68994
14.
Schneider
,
M.
,
Parneix
,
S.
, and
von Wolfersdorf
,
J.
,
2003
, “
Effect of Showerhead Injection on Superposition of Multi-Row Pressure Side Film Cooling With Fan Shaped Holes
,”
ASME
Paper No. GT2003-38693. 10.1115/GT2003-38693
15.
Polanka
,
M.
,
Ethridge
,
M.
,
Cutbirth
,
J.
, and
Bogard
,
D.
,
2000
, “
Effects of Showerhead Injection on Film Cooling Effectiveness for a Downstream Row of Holes
,”
ASME
Paper No. 2000-GT-0240. 10.1115/2000-GT-0240
16.
Kinell
,
M.
,
Utriainen
,
E.
,
Hylén
,
J.
,
Gustavsson
,
J.
,
Bradley
,
A.
,
Karlsson
,
M.
, and
Wren
,
J.
,
2010
, “
Fan Shaped and Cylindrical Holes Studied in Vane Film Cooling Test Rig
,”
ASME
Paper No. GT2010-23308. 10.1115/GT2010-23308
17.
Reiss
,
H.
,
Drost
,
U.
, and
Bölcs
,
A.
,
1998
, “
The Transient Liquid Crystal Technique Employed for Sub- and Transonic Heat Transfer and Film Cooling Measurements in a Linear Cascade
,”
14th Bi-Annual Symposium on Measuring Techniques in Transonic and Supersonic Flow in Cascades and Turbomachines
, Limerick, Ireland, Sept. 3–5, Paper No. LTT-CONF-1998-007.
18.
Schlichting
,
H.
,
1968
,
Boundary Layer Theory
,
6th ed.
,
McGraw-Hill
,
New York
, p.
295
.
19.
Moffat
,
R. J.
,
1985
, “
Using Uncertainty Analysis in the Planning of an Experiment
,”
ASME J. Fluids Eng.
107
(
2
), pp.
173
178
.10.1115/1.3242452
20.
Gustavsson
,
J.
,
Hylen
,
J.
,
Kinell
,
M.
, and
Utriainen
,
E.
,
2010
, “
Window Temperature Impact on IR Thermography for Heat Transfer Measurement
,”
AIAA
Paper No. 2010-0670.10.2514/6.2010-670
21.
Baldauf
,
S.
,
Scheurlen
,
M.
,
Schulz
,
A.
, and
Wittig
,
S.
,
2002
, “
Heat Flux Reduction From Film Cooling and Correlation of Heat Transfer Coefficients From Thermographic Measurements at Engine Like Conditions
,”
ASME
Paper No. GT2002-30181. 10.1115/GT2002-30181
22.
Sellers
,
J. P.
,
1963
, “
Gaseous Film Cooling With Multiple Injection Stations
,”
AIAA J.
,
1
(
9
), pp.
2154
2156
.10.2514/3.2014
23.
Nadali
,
H. N.
,
Karlsson
,
M.
,
Kinell
,
M.
, and
Utriainen
,
E.
,
2012
, “
CFD Based Sensitivity Analysis of Influencing Flow Parameters for Cylindrical and Shaped Holes in a Gas Turbine Vane
,”
ASME
Paper No. GT2012-69023. 10.1115/GT2012-69023
24.
Bunker
,
R. S.
,
2005
, “
A Review of Shaped Hole Turbine Film-Cooling Technology
,”
ASME J. Heat Transfer
,
127
(
4
), pp.
441
453
.10.1115/1.1860562
25.
Gritsch
,
M.
,
Schulz
,
A.
, and
Wittig
,
S.
,
1998
, “
Heat Transfer Coefficient Measurements of Film-Cooling Holes With Expanded Exits
,”
ASME
Paper No. 98-GT-028.10.1115/98-GT-028
26.
Mehendale
,
A. B.
, and
Je-Chin
,
H.
,
1993
, “
Reynolds Number Effect on Leading Edge Film Effectiveness and Heat Transfer Coefficient
,”
Int. J. Heat Mass Transfer
,
36
(
15
), pp.
3723
3730
.10.1016/0017-9310(93)90052-8
27.
Lu
,
Y.
,
Bunker
,
R. S.
,
Dhungel
,
A.
, and
Ekkad
,
S. V.
,
2009
, “
Effect of Trench Width and Depth on Film Cooling From Cylindrical Holes Embedded in Trenches
,”
ASME J. Turbomach.
,
131
(
1
), p.
011003
.10.1115/1.2950057
28.
Drost
,
U.
, and
Bolcs
,
A.
,
1999
, “
Investigation of Detailed Film Cooling Effectiveness and Heat Transfer Distributions on a Gas Turbine Airfoil
,”
ASME J. Turbomach.
,
121
(
2
), pp.
233
242
.10.1115/1.2841306
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