The last 50 years has witnessed significant improvement in film cooling technologies while transpiration cooling is still not implemented in turbine airfoil cooling. Although transpiration cooling could provide higher cooling efficiency with less coolant consumption compared to film cooling, the fine pore structure and high porosity in transpiration cooling metal media always raised difficulties in conventional manufacturing. Recently, the rapid development of additive manufacturing (AM) has provided a new perspective to address such challenge. With the capability of the innovative powder bed selective laser metal sintering (SLMS) AM technology, the complex geometries of transpiration cooling part could be precisely fabricated and endued with improved mechanical strength. This study utilized the SLMS AM technology to fabricate the transpiration cooling and film cooling structures with Inconel 718 superalloy. Five different types of porous media including two perforated plates with different hole pitches, metal sphere packing, metal wire mesh, and blood vessel shaped passages for transpiration cooling were fabricated by EOS M290 system. One laidback fan-shaped film cooling coupon was also fabricated with the same printing process as the control group. Heat transfer tests under three different coolant mass flow rates and four different mainstream temperatures were conducted to evaluate the cooling performance of the printed coupons. The effects of geometry parameters including porosity, surface outlet area ratio, and internal solid–fluid interface area ratio were investigated as well. The results showed that the transpiration cooling structures generally had higher cooling effectiveness than film cooling structure. The overall average cooling effectiveness of blood vessel-shaped transpiration cooling reached 0.35, 0.5, and 0.57, respectively, with low (1.2%), medium (2.4%), and high (3.6%) coolant injection ratios. The morphological parameters analysis showed the major factor that affected the cooling effectiveness most was the internal solid–fluid interface area ratio for transpiration cooling. This study showed that additive manufactured transpiration cooling could be a promising alternative method for turbine blade cooling and worthwhile for further investigations.

References

References
1.
Bunker
,
R. S.
,
2017
, “
Evolution of Turbine Cooling
,”
ASME
Paper No. GT2017-63205.
2.
Bunker
,
R. S.
,
2013
, “
Turbine Heat Transfer and Cooling: An Overview
,”
ASME
Paper No. GT2013-94174.
3.
Han
,
J. C.
,
Dutta
,
S.
, and
Ekkad
,
S. V.
,
2000
,
Gas Turbine Heat Transfer and Cooling Technology
,
Taylor and Francis
,
New York
.
4.
Han
,
J. C.
, and
Huh
,
M.
,
2010
, “
Recent Studies in Turbine Blade Internal Cooling
,”
Heat Transfer Res.
,
41
, pp.
803
828
.
5.
Goldstein
,
R. J.
,
Eckert
,
E. R. G.
, and
Burggraf
,
F.
,
1974
, “
Effects of Hole Geometry and Density on Three-Dimensional Film Cooling
,”
Int. J. Heat Mass Transfer
,
17
(
5
), pp.
595
607
.
6.
Padture
,
N. P.
,
Gell
,
M.
, and
Jordan
,
E. H.
,
2002
, “
Thermal Barrier Coatings for Gas-Turbine Engine Applications
,”
Science
,
296
(
5566
), pp.
280
284
.
7.
Wagner
,
J. H.
,
Johnson
,
B. V.
,
Graziani
,
R. A.
, and
Yeh
,
F. C.
,
1991
, “
Heat Transfer in Rotating Serpentine Passages With Trips Normal to the Flow
,”
ASME
Paper No. 91-GT-265.
8.
Yang
,
L.
,
Ren
,
J.
,
Jiang
,
H.
, and
Ligrani
,
P.
,
2014
, “
Experimental and Numerical Investigation of Unsteady Impingement Cooling Within a Blade Leading Edge Passage
,”
Int. J. Heat Mass Transfer
,
71
, pp.
57
68
.
9.
Armstrong
,
J.
, and
Winstanley
,
D.
,
1987
, “
A Review of Staggered Array Pin Fin Heat Transfer for Turbine Cooling Applications
,”
ASME J. Turbomach.
,
110
(
1
), pp.
94
103
.
10.
Jiang
,
P. X.
,
Huang
,
G.
,
Zhu
,
Y.
,
Liao
,
Z.
, and
Huang
,
Z.
,
2017
, “
Experimental Investigation of Combined Transpiration and Film Cooling for Sintered Metal Porous Struts
,”
Int. J. Heat Mass Transfer
,
108
, pp.
232
243
.
11.
Huang
,
G.
,
Zhu
,
Y.
,
Liao
,
Z.
,
Ouyang
,
X. L.
, and
Jiang
,
P. X.
,
2017
, “
Experimental Investigation of Transpiration Cooling With Phase Change for Sintered Porous Plates
,”
Int. J. Heat Mass Transfer
,
114
, pp.
1201
1213
.
12.
Xu
,
G.
,
Liu
,
Y.
,
Luo
,
X.
,
Ma
,
J.
, and
Li
,
H.
,
2015
, “
Experimental Investigation of Transpiration Cooling for Sintered Woven Wire Mesh Structures
,”
Int. J. Heat Mass Transfer
,
91
, pp.
898
907
.
13.
Ma
,
J.
,
Luo
,
X.
,
Li
,
H.
, and
Liu
,
Y.
,
2016
, “
An Experimental Investigation on Transpiration Cooling Based on the Multilaminated Sintered Woven Wire Mesh Structures
,”
ASME J. Therm. Sci. Eng. Appl.
,
8
(3), p. 031005.
14.
Choi
,
S. H.
,
Scotti
,
S. J.
,
Song
,
K. D.
, and
Ries
,
H.
,
1997
, “
Transpiring Cooling of a Scram-Jet Engine Combustion Chamber
,”
AIAA
Paper No. 97-2576.
15.
Polezhaev
,
J.
,
1997
, “
The Transpiration Cooling for Blades of High Temperatures Gas Turbine
,”
Energy Convers. Manage.
,
38
(
10–13
), pp.
1123
1133
.
16.
Huang
,
Z.
,
Zhu
,
Y.H.
,
Xiong
,
Y. B.
, and
Jiang
,
P. X.
,
2014
, “
Investigation of Transpiration Cooling for Sintered Metal Porous Struts in Supersonic Flow
,”
Appl. Therm. Eng.
,
70
(1), pp. 240–249.
17.
Lefebvre
,
L. P.
,
Banhart
,
J.
, and
Dunand
,
D. C.
,
2008
, “
Porous Metals and Metallic Foams: Current Status and Recent Developments
,”
Adv. Eng. Mater.
,
10
(
9
), pp.
775
787
.
18.
Oh
,
I. H.
,
Nomura
,
N.
,
Masahashi
,
N.
, and
Hanada
,
S.
,
2003
, “
Mechanical Properties of Porous Titanium Compacts Prepared by Powder Sintering
,”
Scr. Mater.
,
49
(
12
), pp.
1197
1202
.
19.
Nakajima
,
H.
,
2006
, “
Fabrication, Properties and Application of Porous Metals With Directional Pores
,”
Prog. Mater. Sci.
,
52
(
7
), pp.
1091
1173
.
20.
Nealy
,
D. A.
, and
Reider
,
S. B.
,
2009
, “
Evaluation of Laminated Porous Wall Materials for Combustor Liner Cooling
,”
ASME J. Eng. Power
,
102
(
2
), pp.
268
276
.
21.
Gu
,
D. D.
,
Meiners
,
W.
,
Wissenbach
,
K.
, and
Poprawe
,
R.
,
2013
, “
Laser Additive Manufacturing of Metallic Components: Materials, Processes and Mechanisms
,”
Int. Mater. Rev.
,
57
(
3
), pp.
133
164
.
22.
Mostafaei
,
A.
,
Stevens
,
E. L.
,
Hughes
,
E.
,
Biery
,
S. D.
,
Hilla
,
C.
, and
Chmielus
,
M.
,
2016
, “
Powder Bed Binder Jet Printed Alloy 625: Densification, Microstructure and Mechanical Properties
,”
Mater. Des.
,
108
, pp.
126
135
.
23.
Yang
,
Q. C.
,
Zhang
,
P.
,
Cheng
,
L.
,
Min
,
Z.
,
Chyu
,
M. K.
, and
To
,
A.
,
2016
, “
Finite Element Modeling and Validation of Thermomechanical Behavior of Ti–6Al–4V in Directed Energy Deposition Additive Manufacturing
,”
Addit. Manuf.
,
12
, pp.
169
177
.
24.
Kruth
,
J. P.
,
Wang
,
X.
,
Laoui
,
T.
, and
Froyen
,
L.
,
2003
, “
Lasers and Materials in Selective Laser Sintering
,”
Assem. Autom.
,
23
(
4
), pp.
357
371
.
25.
Min
,
Z.
,
Parbat
,
S.
,
Yang
,
L.
,
Kang
,
B.
, and
Chyu
,
M. K.
,
2017
, “
Fabrication and Characterization of Additive Manufactured Nickel-Based Oxide Dispersion Strengthened Coating Layer for High-Temperature Application
,”
ASME J. Eng. Gas Turbines Power
,
140
(6), p. 062101.
26.
Kumar
,
S.
,
2003
, “
Selective Laser Sintering: A Qualitative and Objective Approach
,”
J. Miner.
,
55
, pp.
43
47
.
27.
Amato
,
K. N.
,
Gaytan
,
S. M.
,
Murr
,
L. E.
,
Martinez
,
E.
,
Shindo
,
P. W.
,
Hernandez
,
J.
,
Collins
,
S.
, and
Medina
,
F.
,
2012
, “
Microstructures and Mechanical Behavior of Inconel 718 Fabricated by Selective Laser Melting
,”
Acta Mater.
,
60
(
5
), pp.
2229
2239
.
28.
Van Bael
,
S.
,
Kerckhofs
,
G.
,
Moesen
,
M.
,
Pyka
,
G.
,
Schrooten
,
J.
, and
Kruth
,
J. P.
,
2011
, “
Micro-CT-Based Improvement of Geometrical and Mechanical Controllability of Selective Laser Melted Ti6Al4V Porous Structures
,”
Mater. Sci. Eng., A
,
528
(
24
), pp.
7423
7431
.
29.
Dewidar
,
M. M.
,
Khalil
,
K. A.
, and
Lim
,
J. K.
,
2007
, “
Processing and Mechanical Properties of Porous 316 L Stainless Steel for Biomedical Applications
,”
Trans. Nonferrous Met. Soc. China
,
17
(
3
), pp.
468
473
.
30.
Saumweber
,
C.
, and
Schulz
,
A.
,
2012
, “
Effect of Geometry Variations on the Cooling Performance of Fan-Shaped Cooling Holes
,”
ASME J. Turbomach.
,
134
(6), p. 061008.
31.
Kline
,
S. J.
, and
McClintock
,
F. A.
,
1953
, “
Describing Uncertainties in Single Sample Experiments
,”
Mech. Eng.
,
75
(1), pp.
3
8
.
You do not currently have access to this content.