A rig, simulating two adjacent cooling cavities on the trailing side of an airfoil, made up of two trapezoidal channels is tested. Eleven crossover holes on the partition wall between the two channels create the jets. Two exit flow arrangements are investigated—(a) jets, after interaction with the target surface, are turned toward the target channel exit axially and (b) jets exit from a row of racetrack-shaped slots along the target channel. Flow measurements are reported for individual holes and heat transfer coefficients on the eleven target walls downstream the jets are measured using liquid crystals under steady-state conditions. Smooth as well as ribbed target surfaces with four rib angles are tested. Correlations are developed for mass flow rate through each crossover hole, varying the number of crossover holes. Heat transfer coefficient variations along the target channel are reported for a range of 5000–50,000 local jet Reynolds numbers. Major conclusions are: (1) Correlations are developed to successfully predict the air flow rate through each crossover hole for partition walls with six to eleven crossover holes, based on the pressure drop across the holes, (2) impingement heat transfer coefficient correlates well with local jet Reynolds number for both exit flow arrangements, and (3) case of target channel flow exiting from the channel end, at higher jet Reynolds numbers, produce higher heat transfer coefficients than those in the case of flow exiting through a row of slots along the target channel opposite to the crossover holes.

References

References
1.
Chupp
,
R. E.
,
Helms
,
H. E.
,
McFadden
,
P. W.
, and
Brown
,
T. R.
,
1969
, “
Evaluation of Internal Heat-Transfer Coefficients for Impingement Cooled Turbine Blades
,”
J. Aircr.
,
6
(
1
), pp. 203–208.https://arc.aiaa.org/doi/10.2514/3.44036
2.
Metzger
,
D. E.
, and
Bunker
,
R. S.
,
1990
, “
Local Heat Transfer in Internally Cooled Turbine Airfoil Leading Edge Regions—Part I: Impingement Cooling Without Film Coolant Extraction
,”
ASME J. Turbomach.
,
112
(
3
), pp. 451–458.
3.
Bunker
,
R. S.
, and
Metzger
,
D. E.
,
1990
, “
Local Heat Transfer in Internally Cooled Turbine Airfoil Leading Edge Regions—Part II: Impingement Cooling With Film Coolant Extraction
,”
ASME J. Turbomach.
,
112
(
3
), pp. 459–466.
4.
Chang
,
H.
,
Zhang
,
D.
, and
Huang
,
T.
,
1997
, “
Impingement Heat Transfer From Rib Roughened Surface Within Arrays of Circular Jet: The Effect of the Relative Position of the Jet Hole to the Ribs
,”
ASME
Paper No. 97-GT-331.
5.
Akella
,
K. V.
, and
Han
,
J. C.
,
1999
, “
Impingement Cooling in Rotating Two-Pass Rectangular Channels With Ribbed Walls
,”
J. Thermophys. Heat Transfer
,
13
(
3
), pp. 364–371.
6.
Taslim
,
M. E.
,
Setayeshgar
,
L.
, and
Spring
,
S. D.
,
2001
, “
An Experimental Evaluation of Advanced Leading-Edge Impingement Cooling Concepts
,”
ASME J. Turbomach.
,
123
(
1
), pp. 147–153.
7.
Taslim
,
M. E.
,
Pan
,
Y.
, and
Spring
,
S. D.
,
2001
, “
An Experimental Study of Impingement on Roughened Airfoil Leading-Edge Walls With Film Holes
,”
ASME J. Turbomach..
,
123
(
4
), pp. 766–773.
8.
Taslim
,
M. E.
,
Bakhtari
,
K.
, and
Liu
,
H.
,
2003
, “
Experimental and Numerical Investigation of Impingement on a Rib-Roughened Leading-Edge Wall
,”
ASME J. Turbomach.
,
125
(
4
), pp. 682–691.
9.
Taslim
,
M. E.
, and
Khanicheh
,
A.
,
2006
, “
Experimental and Numerical Study of Impingement on an Airfoil Leading-Edge With and Without Showerhead and Gill Film Holes
,”
ASME J. Turbomach.
,
128
(
2
), pp. 310–320.
10.
Taslim
,
M. E.
, and
Bethka
,
D.
,
2009
, “
Experimental and Numerical Impingement Heat Transfer in an Airfoil Leading-Edge Cooling Channel With Cross-Flow
,”
ASME J. Turbomach.
,
131
(
1
), p.
011021
.
11.
Taslim
,
M. E.
, and
Abdelrassoul
,
A.
,
2010
, “
An Experimental and Numerical Investigation of Impingement Heat Transfer in Airfoils Leading-Edge Cooling Channel
,”
Heat Transfer Res.
,
41
(6), pp. 669–685.
12.
Metzger
,
D. E.
,
Fan
,
C. S.
, and
Pennington
,
J. W.
,
1983
, “
Heat Transfer and Flow Friction Characteristics of Very Rough Transverse Ribbed Surfaces With and Without Pin Fins
,” ASME/JSME Thermal Engineering Joint Conference, Honolulu, HI, Mar. 20–24, pp. 429–436.
13.
Abuaf
,
N.
,
Gibbs
,
R.
, and
Baum
,
R.
,
1986
, “
Pressure Drop and Heat Transfer Coefficient Distributions in Serpentine Passages With and Without Turbulence Promoters
,”
Eighth International Heat Transfer Conference
, San Francisco, CA, Aug. 17–22, p.
2837
.
14.
Lau
,
S. C.
,
Han
,
J. C.
, and
Kim
,
Y. S.
,
1989
, “
Turbulent Heat Transfer and Friction in Pin Fin Channels With Lateral Flow Ejection
,”
ASME J. Heat Transfer
,
111
(
1
), pp. 51–58.
15.
Lau
,
S. C.
,
Han
,
J. C.
, and
Batten
,
T.
,
1989
, “
Heat Transfer, Pressure Drop, and Mass Flow Rate in Pin Fin Channels With Long and Short Trailing Edge Ejection Holes
,”
ASME J. Turbomach.
,
111
(
2
), pp. 117–123.
16.
Kumaran
,
T. K.
,
Han
,
J. C.
, and
Lau
,
S. C.
,
1991
, “
Augmented Heat Transfer in a Pin Fin Channel With Short or Long Ejection Holes
,”
Int. J. Heat Mass Transfer
,
34
(
10
), pp. 2617–2628.
17.
Taslim
,
M. E.
,
Li
,
T.
, and
Spring
,
D.
,
1995
, “
Experimental Study of the Effects of Bleed Holes on Heat Transfer and Pressure Drop in Trapezoidal Passages With Tapered Turbulators
,”
ASME J. Turbomach.
,
117
(
2
), pp. 281–289.
18.
Taslim
,
M. E.
, and
Nicolas
,
G.
,
2008
, “
An Experimental and Numerical Investigation of Jet Impingement on Ribs in an Airfoil Trailing-Edge Cooling Channel
,” 12th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery (
ISROMAC-12
), Honolulu, HI, Feb. 17–22, Paper No. ISROMAC12-2008-20238, pp. 1380–1386.
19.
Taslim
,
M. E.
, and
Nongsaeng
,
A.
,
2011
, “
Experimental and Numerical Crossover Jet Impingement in an Airfoil Trailing-Edge Cooling Channel
,”
ASME J. Turbomach.
,
133
(
4
), p. 041009.
20.
Taslim
,
M. E.
, and
Fong
,
M. K. H.
,
2011
, “
Experimental and Numerical Crossover Jet Impingement in a Rib-Roughened Airfoil Trailing-Edge Cooling Channel
,”
ASME
Paper No. GT2011-45995.
21.
Taslim
,
M. E.
, and
Xue
,
F.
,
2017
, “
Crossover Jet Impingement in a Rib-Roughened Trailing-Edge Cooling Channel
,”
ASME J. Turbomach.
,
139
(
7
), p.
071007
.
22.
Kline
,
S. J.
, and
McClintock
,
F. A.
,
1953
, “
Describing Uncertainty in Single-Sample Experiments
,”
ASME Mech. Eng.
,
75
, pp. 3–8.
23.
Taslim
,
M. E.
, and
Wadsworth
,
C. A.
,
1997
, “
An Experimental Investigation of the Rib Surface-Averaged Heat Transfer Coefficient in a Rib-Roughened Square Channel
,”
ASME J. Turbomach.
,
119
(
2
), pp. 381–389.
24.
Korotky
,
G. J.
, and
Taslim
,
M. E.
, “
Rib Heat Transfer Coefficient Measurements in a Rib-Roughened Square Passage
,”
ASME J. Turbomach.
,
120
(
2
), pp. 376–385.
25.
Taslim
,
M. E.
, and
Lengkong
,
A.
,
1998
, “
45° Staggered Rib Heat Transfer Coefficient Measurements in a Square Channel
,”
ASME J. Turbomach.
,
120
(
3
), pp.
571
580
.
26.
Taslim
,
M. E.
, and
Korotky
,
G. J.
,
1998
, “
Low-Aspect-Ratio Rib Heat Transfer Coefficient Measurements in a Square Channel
,”
ASME J. Turbomach.
,
120
(
4
), pp. 831–838.
27.
Taslim
,
M. E.
, and
Lengkong
,
A.
,
1999
, “
45° Round-Corner Rib Heat Transfer Coefficient Measurements in a Square Channel
,”
ASME J. Turbomach.
,
121
(2), pp. 272–280.
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