Abstract

Unlike the ideal conditions considered in most previous studies, the actual cooling flow passage inside gas turbine blades is extremely complex. This complexity is due to the geometrical restrictions resulting from the external cooling holes and blade shape, which change the secondary flow and flow non-uniformity of the internal cooling flow. This study conducted an experimental and numerical analysis to characterize the secondary flow and flow non-uniformity in a realistic internal cooling serpentine passage. Magnetic resonance velocimetry was utilized to measure the average three-dimensional–three-components of the mean velocity. By integrating the flow field, parameters indicating the flow non-uniformity and secondary flow strength were obtained. Reynolds-averaged Navier–Stokes simulations were also conducted, and the Reynolds stress transport model showed relatively good performance when predicting the separation bubble in the U-bend. The secondary flow intensity exponentially decreases after the U-bend, but the rib turbulators maintain the secondary flow at a certain level. Additionally, the high-velocity regions in the inlet zone and beyond the separation bubble create significant flow non-uniformity and inherent shear. At the same time, the turbulence intensity becomes strong at the low-velocity region, which is key for heat transfer enhancement. Therefore, high flow non-uniformity has the potential to enhance heat transfer.

References

1.
Han
,
J.-C.
,
Dutta
,
S.
, and
Ekkad
,
S.
,
2012
,
Gas Turbine Heat Transfer and Cooling Technology
,
Taylor and Francis
,
New York
.
2.
Cardwell
,
N. D.
,
Vlachos
,
P. P.
, and
Thole
,
K. A.
,
2011
, “
Developing and Fully Developed Turbulent Flow in Ribbed Channels
,”
Exp. Fluids
,
50
(
5
), pp.
1357
1371
.
3.
Ahn
,
J.
,
Choi
,
H.
, and
Lee
,
J. S.
,
2005
, “
Large Eddy Simulation of Flow and Heat Transfer in a Channel Roughened by Square or Semicircle Ribs
,”
ASME J. Turbomach.
,
127
(
2
), pp.
263
269
.
4.
Ahn
,
J.
, and
Lee
,
J. S.
,
2010
, “
Large Eddy Simulation of Flow and Heat Transfer in a Channel With a Detached Rib Array
,”
Int. J. Heat Mass Transf.
,
53
(
1–3
), pp.
445
452
.
5.
Duchaine
,
F.
,
Gicquel
,
L.
,
Grosnickel
,
T.
, and
Koupper
,
C.
,
2020
, “
Large-Eddy Simulation of the Flow Developing in Static and Rotating Ribbed Channel
,”
ASME J. Turbomach.
,
142
(
4
), p.
041003
.
6.
Perrot
,
A.
,
Gicquel
,
L.
,
Duchaine
,
L.
,
Odier
,
N.
,
Dombard
,
J.
, and
Grosnickel
,
T.
,
2021
, “
Unsteady Analysis of Heat Transfer Coefficient Distribution in a Static Ribbed Channel for an Established Flow
,”
ASME J. Turbomach.
,
143
(
12
), p.
121004
.
7.
Chanteloup
,
D.
, and
Bölcs
,
A.
,
2003
, “
Flow Effects on the Bend Region Heat Transfer Distribution of 2-Pass Internal Coolant Passages of Gas Turbine Airfoils: Influence of Film Cooling Extraction
,”
ASME Paper No. GT2003-38702
.
8.
Funazaki
,
K.-I.
,
Odagiri
,
H.
,
Horiuchi
,
T.
, and
Kazari
,
M.
,
2018
, “
Detailed Studies on the Flow Field and Heat Transfer Characteristics inside a Realistic Serpentine Cooling Channel with a S-shaped Inlet
,”
ASME Paper No. GT2018-76225
.
9.
Park
,
N.
,
Son
,
C.
,
Yang
,
J.
,
Lee
,
C.
, and
Lee
,
K.
,
2018
, “
Full Surface Heat Transfer Measurement of a Turbine Internal Cooling System Using a Large Scaled Model
,”
ASME Paper No. GT2018-77218
.
10.
Saxer-Felici
,
H.
,
Naik
,
S.
, and
Gritsch
,
M.
,
2013
, “
Heat Transfer Characteristics of a Blade Trailing Edge with Pressure Side Bleed Extraction
,”
ASME Paper No. GT2013-95003
.
11.
Shiau
,
C.-C.
,
Chen
,
A. F.
,
Han
,
J.-C.
, and
Krewinkel
,
R.
,
2020
, “
Detailed Heat Transfer Coefficient Measurements on a Scaled Realistic Turbine Blade Internal Cooling System
,”
ASME J. Therm. Sci. Eng. Appl.
,
12
(
3
), p.
031015
.
12.
Song
,
I.
,
Son
,
C.
,
Yang
,
J.
,
Lee
,
C.
, and
Lee
,
K.
,
2018
, “
Thermal Performance of the Realistic Leading Edge Cooling Passage of a Turbine Blade
,”
ASME Paper No. GT2018-77217
.
13.
Elkins
,
C. J.
, and
Alley
,
M. T.
,
2007
, “
Magnetic Resonance Velocimetry: Applications of Magnetic Resonance Imaging in the Measurement of Fluid Motion
,”
Exp. Fluids
,
43
(
6
), pp.
823
858
.
14.
Elkins
,
C. J.
,
Markl
,
M.
,
Pelc
,
N.
, and
Eaton
,
J. K.
,
2003
, “
4D Magnetic Resonance Velocimetry for Mean Velocity Measurements in Complex Turbulent Flows
,”
Exp. Fluids
,
34
(
4
), pp.
494
503
.
15.
Elkins
,
C. J.
,
Markl
,
M.
,
Iyengar
,
A.
,
Wicker
,
R.
, and
Eaton
,
J. K.
,
2004
, “
Full-Field Velocity and Temperature Measurements Using Magnetic Resonance Imaging in Turbulent Complex Internal Flows
,”
Exp. Fluids
,
25
(
5
), pp.
702
710
.
16.
Tsuru
,
T.
,
Ishida
,
K.
,
Fujita
,
J.
, and
Takeishi
,
K.
,
2019
, “
Three-Dimensional Visualization of Flow Characteristics Using a Magnetic Resonance Imaging in a Lattice Cooling Channel
,”
ASME J. Turbomach.
,
141
(
6
), p.
061003
.
17.
Baek
,
S.
,
Lee
,
S.
,
Hwang
,
W.
, and
Park
,
J. S.
,
2019
, “
Experimental and Numerical Investigation of the Flow in a Trailing Edge Ribbed Internal Cooling Passage
,”
ASME J. Turbomach.
,
141
(
1
), p.
011012
.
18.
Benson
,
M. J.
,
Van Poppel
,
B. P.
,
Elkins
,
C. J.
, and
Owkes
,
M.
,
2019
, “
Three-Dimensional Velocity and Temperature Field Measurements of Internal and External Turbine Blade Features Using Magnetic Resonance Thermometry
,”
ASME J. Turbomach.
,
141
(
7
), p.
071011
.
19.
Benson
,
M. J.
,
Banko
,
A. J.
,
Elkins
,
C. J.
,
An
,
D.-G.
,
Song
,
S.
,
Bruschewski
,
M.
,
Grundmann
,
S.
,
Borup
,
D. D.
, and
Eaton
,
J. K.
,
2020
, “
The 2019 MRV Challenge: Turbulent Flow Through a U-Bend
,”
Exp. Fluids
,
61
(
6
), pp.
1
17
.
20.
Lee
,
J.
,
Ko
,
S.
,
Cho
,
J.-H.
, and
Song
,
S.
,
2017
, “
Validation of Magnetic Resonance Velocimetry for Mean Velocity Measurements of Turbulent Flows in a Circular Pipe
,”
J. Mech. Sci. Technol.
,
31
(
3
), pp.
1275
1282
.
21.
Walker
,
P. G.
,
Cranney
,
G. B.
,
Scheidegger
,
M. B.
,
Waseleski
,
G.
,
Pohost
,
G. M.
, and
Yoganathan
,
A. P.
,
1993
, “
Semiautomated Method for Noise Reduction and Background Phase Error Correction in MR Phase Velocity Data
,”
J. Magn. Reson. Imaging
,
3
(
3
), pp.
521
530
.
22.
Bernstein
,
M. A.
,
Zhou
,
X. J.
,
Polzin
,
J. A.
,
King
,
K. F.
,
Ganin
,
A.
,
Pelc
,
N. J.
, and
Glover
,
G. H.
,
1998
, “
Concomitant Gradient Terms in Phase Contrast MR: Analysis and Correction
,”
Magn. Reson. Med.
,
39
(
2
), pp.
300
308
.
23.
Bruschewski
,
M.
,
Freudenhammer
,
D.
,
Buchenberg
,
W. B.
,
Schiffer
,
H.-P.
, and
Grundmann
,
S.
,
2016
, “
Estimation of the Measurement Uncertainty in Magnetic Resonance Velocimetry Based on Statistical Models
,”
Exp. Fluids
,
57
(
5
), p.
83
.
24.
Barth
,
T.
, and
Jespersen
,
D.
,
1989
, “
The Design and Application of Upwind Schemes on Unstructured Meshes
,”
27th Aerospace Sciences Meeting
, p.
366
.
25.
Darwish
,
M.
, and
Moukalled
,
F.
,
2003
, “
TVD Schemes for Unstructured Grids
,”
Int. J. Heat Mass Transfer
,
46
(
4
), pp.
599
611
.
26.
Loureiro
,
J. B.
,
Alho
,
A. T.
, and
Freire
,
A. P. S.
,
2008
, “
The Numerical Computation of Near-Wall Turbulent Flow Over a Steep Hill
,”
J. Wind Eng. Ind. Aerodyn.
,
96
(
5
), pp.
540
561
.
27.
Menter
,
F. R.
,
1994
, “
Two-Equation Eddy-Viscosity Turbulence Models for Engineering Applications
,”
AIAA
,
32
(
8
), pp.
1598
1605
.
28.
Luo
,
J.
, and
Razinsky
,
E. H.
,
2009
, “
Analysis of Turbulent Flow in 180 deg Turning Ducts With and Without Guide Vanes
,”
ASME J. Turbomach.
,
131
(
2
), p.
021011
.
29.
Wilcox
,
D. C.
,
1993
, “
Comparison of Two-Equation Turbulence Models for Boundary Layers With Pressure Gradient
,”
AIAA
,
31
(
8
), pp.
1414
1421
.
30.
Padilla
,
A. M.
,
2012
,
The Effect of Upstream Perturbations on 3D Annular Diffusers
,
Stanford University
,
Stanford, CA
.
31.
Banko
,
A. J.
,
Coletti
,
F.
,
Schiavazzi
,
D.
,
Elkins
,
C. J.
, and
Eaton
,
J. K.
,
2015
, “
Three-Dimensional Inspiratory Flow in the Upper and Central Human Airways
,”
Exp. Fluids
,
56
(
6
), pp.
1
12
.
32.
Banko
,
A. J.
,
Coletti
,
F.
,
Elkins
,
C. J.
, and
Eaton
,
J. K.
,
2016
, “
Oscillatory Flow in the Human Airways From the Mouth Through Several Bronchial Generations
,”
Int. J. Heat Fluid Flow
,
61
, pp.
45
57
.
33.
Han
,
J.-C.
, and
Park
,
J. S.
,
1988
, “
Developing Heat Transfer in Rectangular Channels With Rib Turbulators
,”
Int. J. Heat Mass Transfer
,
31
(
1
), pp.
183
195
.
34.
Kim
,
J.
,
Yadav
,
M.
, and
Kim
,
S.
,
2014
, “
Characteristics of Secondary Flow Induced by 90-Degree Elbow in Turbulent Pipe Flow
,”
Eng. Appl. Comput. Fluid Mech.
,
8
(
2
), pp.
229
239
.
35.
Wilcox
,
D. C.
,
2006
,
Turbulence Modelling for CFD
,
DCW Indust.
,
La Canada, CA
.
36.
Sohn
,
H.
,
Kim
,
J.
,
Kim
,
T.
,
Moon
,
H. K.
, and
Cho
,
H. H.
,
2021
, “
Effects of Tip-Bleed Holes on Two-Pass Channel on Heat Transfer With Various Aspect Ratios
,”
Case Stud. Therm.
,
28
, p.
101593
.
37.
Luo
,
L.
,
Chen
,
Q.
,
Du
,
W.
,
Wang
,
S.
,
Sundén
,
B.
, and
Zhang
,
X.
,
2018
, “
Computational Investigation of the Dust Hole Effect on the Heat Transfer and Friction Factor Characteristics in a U Bend Channel
,”
Appl. Therm. Eng.
,
140
, pp.
166
179
.
38.
Luo
,
L.
,
Zhao
,
Z.
,
Kan
,
X.
,
Qiu
,
D.
,
Wang
,
S.
, and
Wang
,
Z.
,
2019
, “
On the Heat Transfer and Flow Structures’ Characteristics of the Turbine Blade Tip Underside With Dirt Purge Holes at Different Locations by Using Topology Analysis
,”
J. Turbomachin.
,
141
(
7
), p.
071004
.
39.
Ekkad
,
S. V.
, and
Han
,
J.-C.
,
1997
, “
Detailed Heat Transfer Distributions in Two-Pass Square Channels With Rib Turbulators
,”
Int. J. Heat Mass Transfer
,
40
(
11
), pp.
2525
2537
.
40.
Son
,
S.
,
Kihm
,
K.
, and
Han
,
J.-C.
,
2002
, “
PIV Flow Measurements for Heat Transfer Characterization in Two-Pass Square Channels With Smooth and 90 Ribbed Walls
,”
Int. J. Heat Mass Transfer
,
45
(
24
), pp.
4809
4822
.
41.
Siw
,
S. C.
,
Chyu
,
M. K.
,
Um
,
J. Y.
, and
Lee
,
C.-P.
,
2016
, “
Detailed Experimental Characterization of Heat Transfer Coefficient Over the Internal Cooling Passages of an Additive Manufactured Turbine Airfoil
,”
ASME Paper No. GT2016-57787
.
42.
Webb
,
R. L.
, and
Eckert
,
E. R. G.
,
1972
, “
Application of Rough Surfaces to Heat Exchanger Design
,”
Int. J. Heat Mass Transfer
,
15
(
9
), pp.
1649
1658
.
43.
Han
,
J.-C.
,
1988
, “
Heat Transfer and Friction Characteristics in Rectangular Channels With Rib Turbulators
,”
ASME J. Heat Transfer-Trans. ASME
,
110
(
2
), pp.
321
328
.
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