Turbine blades are cooled by a jet flow from expanded exit holes (EEH) forming a low-temperature film over the blade surface. Subsequent to our report on the suction-side (low-pressure, high-speed region), computational analyses are performed to examine the cooling effectiveness of the flow from EEH located at the leading edge as well as at the pressure-side (high-pressure, low-speed region). Unlike the case of the suction-side, the flow through EEH on the pressure-side is either subsonic or transonic with a weak shock front. The cooling effectiveness, η (defined as the temperature difference between the hot gas and the blade surface as a fraction of that between the hot gas and the cooling jet), is higher than the suction-side along the surface near the exit of EEH. However, its magnitude declines sharply with an increase in the distance from EEH. Significant effects on the magnitude of η are observed and discussed in detail of (1) the coolant mass flow rate (0.001, 0.002, and 0.004 (kg/s)), (2) EEH configurations at the leading edge (vertical EEH at the stagnation point, 50 deg into the leading-edge suction-side, and 50 deg into the leading-edge pressure-side), (3) EEH configurations in the midregion of the pressure-side (90 deg (perpendicular to the mainstream flow), 30 deg EEH tilt toward upstream, and 30 deg tilt toward downstream), and (4) the inclination angle of EEH.

References

References
1.
Goldstein
,
R. J.
,
1971
,
Film Cooling, Advances in Heat Transfer
, Vol.
7
,
Academic Press
,
San Diego, CA
, pp.
321
379
.
2.
Goldstein
,
R. J.
,
Eckert
,
E. R. G.
, and
Burggarf
,
F.
,
1974
, “
Effect of Hole Geometry and Density on Three Dimensional Film Cooling
,”
Int. J. Heat Mass Transfer
,
17
(
5
), pp.
595
607
.
3.
Lopez-Pena
,
F.
, and
Arts
,
T.
,
1993
, “
On the Development of a Film Cooling Layer
,”
Heat Transfer and Cooling in Gas Turbines
, Vol.
36
, Paper No. AGARD-CP-527.
4.
Thole
,
K.
,
Gritsch
,
M.
,
Schultz
,
A.
, and
Wittig
,
S.
,
1996
, “
Flow Field Measurements for Film Cooling Holes With Expanded Exits
,”
ASME
Paper No. 96-GT-174.
5.
Hildebrandt
,
T.
,
Ganzert
,
W.
, and
Fottner
,
L.
,
2000
, “
Systematic Experimental and Numerical Investigations on the Aerothermodynamics of a Film Cooled Turbine Cascade With Variation of the Cooling Hole Shape: Part II—Numerical Approach
,”
ASME
Paper No. 2000-GT-0298.
6.
Barthet
,
S.
, and
Bario
,
F.
,
2001
, “
Experimental Investigation of Film Cooling Flow Induced by Shaped Holes on a Turbine Blade
,”
Ann. N. Y. Acad. Sci.
,
934
, pp.
313
320
.
7.
Bell
,
C. M.
,
Hamakawa
,
H.
, and
Ligrani
,
P. M.
,
2000
, “
Film Cooling From Shaped Holes
,”
ASME J. Heat Transfer
,
122
(
2
), pp.
224
232
.
8.
Guo
,
S. M.
,
Lai
,
C. C.
,
Jones
,
T. V.
,
Lock
,
G. D.
, and
Rawlinson
,
A. J.
,
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
.
9.
Sargison
,
J. E.
,
Guo
,
S. M.
,
Oldfield
,
M. L. G.
, and
Lock
,
G. D.
,
2002
, “
A Converging Slot Hole Film Cooling Geometry—Part 1: Low-Speed Flat-Plate Heat Transfer and Loss
,”
ASME J. Turbomach.
,
124
(
3
), pp.
453
460
.
10.
Bohn
,
D.
,
Ren
,
J.
, and
Kusterer
,
K.
,
2003
, “
Conjugate Heat Transfer Analysis for Film Cooling Configurations With Different Hole Geometries
,”
ASME
Paper No. GT2003-38369.
11.
Gritsch
,
M.
,
Schultz
,
A.
, and
Wittig
,
S.
,
1998
, “
Heat Transfer Coefficients Measurement of Film-Cooling With Expanded Exits
,”
ASME
Paper No. 98-GT-028.
12.
Yu
,
Y.
,
Yen
,
C.-H.
,
Shih
,
T. I.-P.
,
Chyu
,
M. K.
, and
Gogineni
,
S.
,
1999
, “
Film Cooling Effectiveness and Heat Transfer Coefficient Distributions Around Diffusion Shaped Holes
,”
ASME J. Heat Transfer
,
124
(5), pp. 820–827.
13.
Wilfert
,
G.
, and
Fottner
,
L.
,
1996
, “
The Aerodynamic Mixing Effect of Discrete Cooling Jet With Mainstream Flow on a Highly Loaded Turbine Blade
,”
ASME J. Turbomach.
,
118
(
3
), pp.
468
478
.
14.
Haven
,
B. A.
,
Yamagata
,
D. K.
,
Kurosaka
,
M.
,
Yamawaki
,
S.
, and
Maya
,
T.
,
1997
, “
Anti-Kidney Pair of Vortices in Shaped Holes and Their Influence on Film Cooling Effectiveness
,”
ASME
Paper No. 97-GT-045.
15.
Saumweber
,
C.
,
Schultz
,
A.
, and
Witting
,
S.
,
2003
, “
Free-Stream Turbulence Effect on Film Cooling With Shaped Holes
,”
ASME J. Turbomach.
,
125
(
1
), pp.
65
73
.
16.
Baheri-Islami
,
S.
, and
Jubran
,
B. A.
,
2012
, “
The Effect of Turbulence Intensity on Film Cooling of Gas Turbine Blade From Trenched Shaped Holes
,”
J. Heat Mass Transfer
,
48
(
5
), pp.
831
840
.
17.
Kohli
,
A.
, and
Thole
,
K. A.
,
1998
, “
Entrance Effects on Diffused Film Cooling Holes
,”
ASME
Paper No. 98-GT-402.
18.
Makki
,
Y. H.
, and
Jakubowski
,
G. S.
,
1986
, “
An Experimental Study of Film Cooling From Diffused Trapezoidal Shaped Holes
,”
AIAA
Paper No. 1986-1326.
19.
Sargison
,
J. E.
,
Guo
,
S. M.
,
Oldfield
,
M. L. G.
, and
Lock
,
G. D.
,
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
.
20.
Sargison
,
J. E.
,
Oldfield
,
M. L. G.
,
Guo
,
S. M.
,
Lock
,
G. D.
, and
Rawlinson
,
A. J.
,
2005
, “
Flow Visualization of the External Flow From a Converging Slot-Hole Film Cooling Geometry
,”
Exp. Fluid
,
38
(
3
), pp.
304
318
.
21.
Azzi
,
A.
, and
Jubran
,
B. A.
,
2007
, “
Numerical Modelling of Film Cooling From Converging Slot-Hole
,”
Heat Mass Transfer
,
43
(4), pp.
381
388
.
22.
Liu
,
C. L.
,
Zhu
,
H. R.
,
Bai
,
J. T.
, and
Xu
,
D. C.
,
2010
, “
Film Cooling Performance of Converging Slot-Hole Rows on a Gas Turbine Blade
,”
Int. J. Heat Mass Transfer
,
53
(
23–24
), pp.
5232
5241
.
23.
Liu
,
C. L.
,
Zhu
,
H. R.
,
Bai
,
J. T.
, and
Xu
,
D. C.
,
2009
, “
Experimental Research on the Thermal Performance of Converging Slot Holes With Different Divergence Angles
,”
Exp. Therm. Fluid Sci.
,
33
(
5
), pp.
808
817
.
24.
Schmidt
,
D. L.
,
Sen
,
B.
, and
Bogard
,
D. G.
,
1994
, “
Film Cooling With Compound Angle Holes: Adiabatic Effectiveness
,”
ASME
Paper No. 94-GT-312.
25.
Chen
,
P. H.
,
Hung
,
M. S.
, and
Ding
,
P. P.
,
2001
, “
Film Cooling Performance on Curved Walls With Compound Angle Hole Configuration
,”
Ann. N. Y. Acad. Sci.
,
934
(1), pp.
353
360
.
26.
Dittmar
,
J.
,
Schultz
,
A.
, and
Wittig
,
S.
,
2002
, “
Assessment of Various Film-Cooling Configurations Including Shaped and Compound Angle Holes Based on Large-Scale Experiments
,”
ASME J. Turbomach.
,
125
(1), pp. 57–64.
27.
McGrath
,
E. L.
,
Leylek
,
J. H.
, and
Buck
,
F. A.
,
2002
, “
Film Cooling on a Modern HP Turbine Blade—Part IV: Compound Angle Shaped Holes
,”
ASME
Paper No. GT2002-30521.
28.
Liu
,
C. L.
,
Zhu
,
H. R.
,
Zhang
,
X.
,
Xu
,
D. C.
, and
Zhang
,
Z. W.
,
2014
, “
Experimental Investigation on the Leading Edge Film Cooling of Cylindrical and Laid-Back Holes With Different Radial Angles
,”
Int. J. Heat Mass Transfer
,
71
, pp.
615
625
.
29.
Baheri-Islami
,
S.
,
Alavi-Tabrizi
,
S. P.
,
Jubran
,
B. A.
, and
Esmaeilzadeh
,
E.
,
2010
, “
Influence of Trenched Shaped Holes on Turbine Blade Leading Edge Film Cooling
,”
Heat Transfer Eng.
,
31
(
10
), pp.
889
906
.
30.
Ganzert
,
W.
,
Hildebrandt
,
T.
, and
Fottner
,
L.
,
2000
, “
Systematic Experimental and Numerical Investigation on the Aerodynamics of a Film Cooled Turbine Cascade With Variation of the Cooling Shape—Part 1: Experimental Approach
,”
ASME
Paper No. 2000-GT-0295.
31.
Salvadori
,
S.
,
Montomoli
,
F.
, and
Martelli
,
F.
,
2013
, “
Film-Cooling Performance in Supersonic Flows: Effect of Shock Impingement
,”
Proc. Inst. Mech. Eng., Part A
,
227
(
3
), pp.
295
305
.
32.
Yu
,
Z. L.
,
Xu
,
T.
,
Li
,
J. L.
,
Ma
,
L.
, and
Xu
,
T. Z.
,
2013
, “
Comparison of a Series of Double Chamber Model With Various Hole Angles for Enhancing Cooling Effectiveness
,”
Int. Commun. Heat Mass Transfer
,
44
, pp.
38
44
.
33.
Yao
,
Y.
,
Zhang
,
J. Z.
, and
Wang
,
L. P.
,
2013
, “
Film Cooling on a Gas Turbine Blade Suction Side With Converging Slot-Hole
,”
Int. J. Therm. Sci.
,
65
, pp.
267
279
.
34.
Yu
,
Y.
,
Jing-Zhou
,
Z.
, and
Xiao-Ming
,
T.
,
2014
, “
Numerical Study of Film Cooling From Converging Slot-Hole on a Gas Turbine Blade Suction Side
,”
Int. Commun. Heat Mass Transfer
,
52
, pp.
61
72
.
35.
Yusop
,
N. M.
,
Ali
,
A. H.
, and
Abdullah
,
M. Z.
,
2013
, “
Computational Study of a New Scheme for a Film-Cooling Hole on Convex Surface of Turbine Blades
,”
Int. Commun. Heat Mass Transfer
,
43
, pp.
90
99
.
36.
Hay
,
N.
, and
Lampard
,
D.
,
1998
, “
Discharge Coefficient of Turbine Cooling Holes: A Review
,”
ASME J. Turbomach.
,
120
(2), pp.
317
319
.
37.
Gritsch
,
M.
,
Schulz
,
A.
, and
Wittig
,
S.
,
1998
, “
Discharge Coefficient Measurements of Film-Cooling Holes With Expanded Exits
,”
ASME J. Turbomach.
,
120
(
3
), pp.
557
563
.
38.
Lutum
,
E.
, and
Johnson
,
B. V.
,
1999
, “
Influence of the Hole Length-to-Diameter Ratio on Film Cooling With Cylindrical Holes
,”
ASME J. Turbomach.
,
121
(
2
), pp.
209
216
.
39.
Jocksch
,
A.
,
2004
, “
Effect of the Vortex Whistle on the Discharge Coefficient of Orifices
,”
AIAA J.
,
42
(
5
), pp.
1048
1050
.
40.
Gritsch
,
M.
,
Schulz
,
A.
, and
Wittig
,
S.
,
1998
, “
Adiabatic Wall Effectiveness Measurements of Film-Cooling Holes With Expanded Exits
,”
ASME J. Turbomach.
,
120
(
3
), pp.
549
556
.
41.
Uzol
,
O.
,
Camci
,
C.
, and
Glezer
,
B.
,
2001
, “
Aerodynamic Loss Characteristics of a Turbine Blade With Trailing Edge Coolant Ejection—Part 1: Effect of Cut-Back Length, Spanwise Rib Spacing, Free-Stream Reynolds Number, and Chordwise Rib Length on Discharge Coefficients
,”
ASME J. Turbomach.
,
123
(
2
), pp.
238
248
.
42.
Zuniga
,
H.
,
Krishnan
,
V.
,
Ling
,
J.
, and
Kapat
,
J.
,
2007
, “
Trend in Film Cooling Effectiveness Caused by Increasing Angle of Diffusion Through a Row of Conical Holes
,”
ASME
Paper No. GT2007-28287.
43.
Forghan
,
F.
,
1995
, “
Discharge Coefficient of Diffusion Holes
,”
AIAA
Paper No. 95-3622.
44.
Forghan
,
F.
,
Narusawa
,
U.
, and
Metghalchi
,
M.
,
2010
, “
Discharge Coefficient of Expanded Exit Holes for Film Cooling of Turbine Blades
,”
AIAA J. Propul. Power
,
26
(6), pp.
1322
1325
.
45.
Forghan
,
F.
,
Askari
,
O.
,
Narusawa
,
U.
, and
Metghalchi
,
H.
,
2014
, “
Film Cooling of Turbine Blade Surface With Extended Exit Holes
,”
ASME
Paper No. ES2014-6527.
46.
Forghan
,
F.
,
Askari
,
O.
,
Narusawa
,
U.
, and
Metghalchi
,
H.
,
2014
, “
Cooling of Turbine Blade Surface With Extended Exit Holes: Parametric Study
,”
ASME
Paper No. IMECE2014-36912.
47.
Forghan
,
F.
,
Askari
,
O.
,
Narusawa
,
U.
, and
Metghalchi
,
H.
,
2016
, “
Cooling of Turbine Blade Surface With Expanded Exit Holes: Computational Suction-Side Analysis
,”
ASME J. Energy Resour. Technol.
,
138
(
5
), p.
051602
.
You do not currently have access to this content.