Abstract

Gas turbine blades are equipped with internal cooling channels which are connected by 180 deg bends. Due to combined effects of Coriolis force and centrifugal buoyancy force, the heat transfer increases on the trailing side (pressure side) and decreases on the leading side (suction side) for radially outward flow. The trend in heat transfer is opposite for radially inward flow. This configuration leads to nonuniform blade temperature which in unfavorable for blade lifespan. This paper presents a novel eight-passage serpentine design, where passages are arranged along the chord of the blade, to rectify the negative effects of Coriolis force on heat transfer and is an extension four- and six-passage smooth channel studies conducted by the authors earlier. Transient liquid crystal thermography (TLCT) is carried out for detailed measurement of heat transfer coefficients. Heat transfer experiments were performed for Reynolds numbers between 14,264 and 83,616 under stationary conditions. For experiments under rotation, non-dimensional Rotation number is set as 0.05. Heat transfer enhancement levels of nearly twice the Dittus–Boelter correlation (for developed flow in smooth tubes) are obtained under stationary conditions. Under rotation, it is seen that the heat transfer enhancement levels on the leading and trailing sides are similar to each other and also with the stationary condition. Some differences in heat transfer are observed on local level, when rotation cases are compared against the stationary cases. Numerically predicted flow field is presented to support the experimental findings.

References

1.
Han
,
J. C.
,
2013
, “
Fundamental Gas Turbine Heat Transfer
,”
ASME J. Therm. Sci. Eng. Appl.
,
5
(
2
), p.
021007
. 10.1115/1.4023826
2.
Han
,
J. C.
, and
Dutta
,
S.
,
2001
, “
Recent Developments in Turbine Blade Internal Cooling
,”
Ann. N. Y. Acad. Sci.
,
934
(
1
), pp.
162
178
. 10.1111/j.1749-6632.2001.tb05850.x
3.
Johnson
,
B. V.
,
Wagner
,
J. H.
,
Steuber
,
G. D.
, and
Yeh
,
F. C.
,
1994
, “
Heat Transfer in Rotating Serpentine Passages With Trips Skewed to the Flow
,”
ASME. J. Turbomach.
,
116
(
1
), pp.
113
123
. 10.1115/1.2928265
4.
Bonhoff
,
B.
,
Tomm
,
U.
,
Johnson
,
B. V.
, and
Jennions
,
I.
, “
Heat Transfer Predictions for Rotating U-Shaped Coolant Channels With Skewed Ribs and With Smooth Walls,” Proceedings of the ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition. Volume 3: Heat Transfer; Electric Power; Industrial and Cogeneration
,
Orlando, FL
,
June 2–5
,
ASME
Paper No. V003T09A027
. 10.1115/97-gt-162
5.
Wagner
,
J. H.
,
Johnson
,
B. V.
,
Graziani
,
R. A.
, and
Yeh
,
F. C.
, “
Heat Transfer in Rotating Serpentine Passages With Trips Normal to the Flow,” Proceedings of the ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition. Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration
,
Orlando, FL
,
June 3–6
,
ASME
Paper No. V004T09A015
. 10.1115/91-gt-265
6.
Parsons
,
J. A.
,
Han
,
J. C.
, and
Zhang
,
Y.
,
1995
, “
Effect of Model Orientation and Wall Heating Condition on Local Heat Transfer in a Rotating Two-Pass Square Channel With Rib Turbulators
,”
Int. J. Heat Mass Transfer
,
38
(
7
), pp.
1151
1159
. 10.1016/0017-9310(94)00246-R
7.
Al-Hadhrami
,
L.
, and
Han
,
J. C.
,
2003
, “
Effect of Rotation on Heat Transfer in Two-Pass Square Channels With Five Different Orientations of 45 Angled Rib Turbulators
,”
Int. J. Heat Mass Transfer
,
46
(
4
), pp.
653
669
. 10.1016/S0017-9310(02)00325-3
8.
Rallabandi
,
A. P.
,
Liu
,
Y.
, and
Han
,
J.
,
2011
, “
Heat Transfer in Trailing Edge Wedge-Shaped Pin-Fin Channels With Slot Ejection Under High Rotation Numbers
,”
ASME J. Therm. Sci. Eng. Appl.
,
3
(
2
), p.
021007
. 10.1115/1.4003746
9.
Lamont
,
J. A.
,
Ekkad
,
S. V.
, and
Alvin
,
M. A.
,
2012
, “
Detailed Heat Transfer Measurements Inside Rotating Ribbed Channels Using the Transient Liquid Crystal Technique
,”
ASME J. Therm. Sci. Eng. Appl.
,
4
(
1
), p.
011002
. 10.1115/1.4005604
10.
Saha
,
K.
,
Acharya
,
S.
, and
Nakamata
,
C.
,
2013
, “
Heat Transfer Enhancement and Thermal Performance of Lattice Structures for Internal Cooling of Airfoil Trailing Edges
,”
ASME J. Therm. Sci. Eng. Appl.
,
5
(
1
), p.
011001
. 10.1115/1.4007277
11.
Huang
,
S.
, and
Liu
,
Y.
,
2013
, “
High Rotation Number Effect on Heat Transfer in a Leading Edge Cooling Channel of Gas Turbine Blades With Three Channel Orientations
,”
ASME J. Therm. Sci. Eng. Appl.
,
5
(
4
), p.
041003
. 10.1115/1.4023888
12.
Yang
,
S.
,
Han
,
J.
,
Azad
,
S.
, and
Lee
,
C.
,
2015
, “
Heat Transfer in Rotating Serpentine Coolant Passage With Ribbed Walls at Low Mach Numbers
,”
ASME J. Therm. Sci. Eng. Appl.
,
7
(
1
), p.
011013
. 10.1115/1.4028905
13.
Dutta
,
S.
, and
Han
,
J.
,
1996
, “
Local Heat Transfer in Rotating Smooth and Ribbed Two-Pass Square Channels With Three Channel Orientations
,”
ASME J. Heat Transfer
,
118
(
3
), pp.
578
584
. 10.1115/1.2822671
14.
Singh
,
P.
, and
Ekkad
,
S. V.
, “
Experimental Investigation of Rotating Rib Roughened Two-Pass Square Duct With Two Different Channel Orientations,” Proceedings of the ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. Volume 5A: Heat Transfer
,
Charlotte, NC
,
June 26–30
,
ASME
Paper No. V05AT16A012
. 10.1115/gt2017-64225
15.
Singh
,
P.
,
Li
,
W.
,
Ekkad
,
S. V.
, and
Ren
,
J.
,
2017
, “
A New Cooling Design for Rib Roughened Two-Pass Channel Having Positive Effects of Rotation on Heat Transfer Enhancement on Both Pressure and Suction Side Internal Walls of a Gas Turbine Blade
,”
Int. J. Heat Mass Transfer
,
115
(Part B)
, pp.
6
20
. 10.1016/j.ijheatmasstransfer.2017.07.128
16.
Singh
,
P.
,
Ji
,
Y.
, and
Ekkad
,
S. V.
,
2019
, “
Multi-Pass Serpentine Cooling Designs for Negating Coriolis Force Effect on Heat Transfer: Smooth Channels
,”
ASME J. Turbomach.
,
141
(
7
), p.
071001
. 10.1115/1.4042565
17.
Singh
,
P.
, and
Ekkad
,
S. V.
,
2018
, “
An Eight-Passage Serpentine Design for Negating Coriolis Force Effect on Heat Transfer,” Proceedings of the ASME 2018 International Mechanical Engineering Congress and Exposition. Volume 8B: Heat Transfer and Thermal Engineering
,
Pittsburgh, PA
,
Nov. 9–15
,
ASME
Paper No. V08BT10A028
. 10.1115/imece2018-86354
18.
Bergman
,
T. L.
,
Incropera
,
F. P.
,
DeWitt
,
D. P.
, and
Lavine
,
A. S.
,
2011
,
Fundamentals of Heat and Mass Transfer
,
John Wiley & Sons
,
New York
.
19.
Camci
,
C.
,
Kim
,
K.
, and
Hippensteele
,
S. A.
,
1992
, “
A New Hue Capturing Technique for the Quantitative Interpretation of Liquid Crystal Images Used in Convective Heat Transfer Studies
,”
ASME J. Turbomach.
,
114
(
4
), pp.
765
775
. 10.1115/1.2928030
20.
Moffat
,
R. J.
,
1988
, “
Describing the Uncertainties in Experimental Results
,”
Exp. Therm. Fluid. Sci.
,
1
(
1
), pp.
3
17
. 10.1016/0894-1777(88)90043-X
21.
Sewall
,
E. A.
, and
Tafti
,
D. K.
,
2007
, “
Large Eddy Simulation of Flow and Heat Transfer in the Developing Flow Region of a Rotating Gas Turbine Blade Internal Cooling Duct With Coriolis and Buoyancy Forces
,”
ASME J. Turbomach.
,
130
(
1
), p.
011005
. 10.1115/1.2437779
22.
Webb
,
R. L.
,
1981
, “
Performance Evaluation Criteria for Use of Enhanced Heat Transfer Surfaces in Heat Exchanger Design
,”
Int. J. Heat Mass Transfer
,
24
(
4
), pp.
715
726
. 10.1016/0017-9310(81)90015-6
23.
Wang
,
C.
,
Wang
,
L.
, and
Sundén
,
B.
,
2015
, “
Heat Transfer and Pressure Drop in a Smooth and Ribbed Turn Region of a Two-Pass Channel
,”
Appl. Therm. Eng.
,
85
, pp.
225
233
. 10.1016/j.applthermaleng.2015.03.079
You do not currently have access to this content.