Data which illustrate the effects of jet-to-target plate distance and Reynolds number on the heat transfer from an array of jets impinging on a flat plate are presented. Considered are Reynolds numbers Rej ranging from 8200 to 52,000 with isentropic jet Mach numbers of approximately 0.1 to 0.2. Jet-to-target plate distances Z of 1.5D, 3.0D, 5.0D, and 8.0D are employed, where D is the impingement hole diameter. Streamwise and spanwise hole spacings are 8D. Local and spatially-averaged Nusselt numbers show strong dependence on the impingement jet Reynolds number for all situations examined. Experimental results also illustrate the dependence of local Nusselt numbers on normalized jet-to-target plate distance, especially for smaller values of this quantity. The observed variations are partially due to accumulating cross-flows produced as the jets advect downstream, as well as the interactions of the vortex structures, which initially form around the jets and then impact and interact as they advect away from stagnation points along the impingement target surface. The highest spatially-averaged Nusselt numbers are present for Z/D = 3.0 for Rej of 8200, 20,900, and 30,000. When Rej = 52,000, spatially-averaged Nusselt numbers increase as Z/D decreases, with the highest value present at Z/D = 1.5.

References

References
1.
Martin
,
H.
,
1977
, “
Heat and Mass Transfer Between Impinging Gas Jets and Solid Surfaces
,”
Adv. Heat Transfer
,
13
, pp.
1
60
.10.1016/S0065-2717(08)70221-1
2.
Schulz
,
A.
,
2001
, “
Combustor Liner Cooling Technology in Scope of Reduced Pollutant Formation and Rising Thermal Efficiencies
,”
Ann. N. Y. Acad. Sci.
,
934
, pp.
135
146
.10.1111/j.1749-6632.2001.tb05848.x
3.
Kercher
,
D. M.
, and
Tabakoff
,
W.
,
1970
, “
Heat Transfer By a Square Array of Round Air Jets Impinging Perpendicular to a Flat Surface Including the Effect of Spent Air
,”
ASME J. Eng. Power
,
92
(1), pp.
73
82
.10.1115/1.3445306
4.
Metzger
,
D. E.
, and
Korstad
,
R.
,
1972
, “
Effects of Crossflow on Impingement Heat Transfer
,”
ASME J. Eng. Power
,
94
(1), pp.
35
41
.10.1115/1.3445616
5.
Chance
,
J. L.
,
1974
, “
Experimental Investigation of Air Impingement Heat Transfer Under an Array of Round Jets
,”
Tappi J.
,
57
(
6
), pp.
108
112
.
6.
Metzger
,
D. E.
,
Florschuetz
,
L. W.
,
Takeuchi
,
D. I.
,
Behee
,
R. D.
, and
Berry
,
R. A.
,
1979
, “
Heat Transfer Characteristics for Inline and Staggered Arrays of Circular Jets With Crossflow of Spent Air
,”
ASME Trans. J. Heat Transfer
,
101
(3), pp.
526
531
.10.1115/1.3451022
7.
Florschuetz
,
L. W.
,
Truman
,
C. R.
, and
Metzger
,
D. E.
,
1981
, “
Streamwise Flow and Heat Transfer Distributions for Jet Array Impingement With Crossflow
,”
ASME Trans. J. Heat Transfer
,
103
(2), pp.
337
342
.10.1115/1.3244463
8.
Obot
,
N. T.
, and
Trabold
,
T. A.
,
1987
, “
Impingement Heat Transfer Within Arrays of Circular Jets: Part 1—Effects of Minimum, Intermediate, and Complete Crossflow for Small and Large Spacings
,”
ASME Trans. J. Heat Transfer
,
109
(4), pp.
872
879
.10.1115/1.3248197
9.
Bailey
,
J. C.
, and
Bunker
,
R. S.
,
2002
, “
Local Heat Transfer and Flow Distributions For Impinging Jet Arrays of Dense and Sparse Extent
,”
ASME
Paper No. GT2002-30473.10.1115/GT2002-30473
10.
San
,
J. Y.
,
Tsou
,
Y. M.
, and
Chen
,
Z. C.
,
2007
, “
Impingement Heat Transfer of Staggered Arrays of Air Jets Confined in a Channel
,”
Int. J. Heat Mass Transfer
,
50
(
19–20
), pp.
3718
3727
.10.1016/j.ijheatmasstransfer.2007.02.027
11.
Miao
,
J. M.
,
Wu
,
C. Y.
, and
Chen
,
P. H.
,
2009
, “
Numerical Investigation of Confined Multiple-Jet Impingement Cooling Over a Flat Plat at Different Crossflow Orientations
,”
Numer. Heat Transfer, Part A
,
55
(
11
), pp.
1019
1050
.10.1080/10407780903014335
12.
Vadiraj
,
K.
, and
Prabhu
,
S. V.
,
2008
, “
Influence of Spanwise Pitch on Local Heat Transfer Distribution for In-Line Arrays of Circular Jets With Spent Air Flow in Two Opposite Directions
,”
Exp. Therm. Fluid Sci.
,
33
(1), pp.
84
95
.10.1016/j.expthermflusci.2008.07.004
13.
Brevet
,
P.
,
Dejeu
,
C.
,
Dorignac
,
E.
,
Jolly
,
M.
, and
Vullierme
,
J. J.
,
2002
, “
Heat Transfer to a Row of Impinging Jets in Consideration of Optimization
,”
Int. J. Heat Mass Transfer
,
45
(20), pp.
4191
4200
.10.1016/S0017-9310(02)00128-X
14.
Kline
,
S. J.
, and
McClintock
,
F. A.
,
1953
, “
Describing Uncertainties in Single Sample Experiments
,”
Mech. Eng.
,
75
, pp.
3
8
.
15.
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
16.
Park
,
J.
,
Goodro
,
M.
,
Ligrani
,
P. M.
,
Fox
,
M.
, and
Moon
,
H.-K.
,
2007
, “
Separate Effects of Mach Number and Reynolds Number on Jet Array Impingement Heat Transfer
,”
ASME J. Turbomach.
,
129
(
2
), pp.
269
280
.10.1115/1.2437774
17.
Chung
,
Y. M.
, and
Luo
,
K. H.
,
2002
, “
Unsteady Heat Transfer Analysis on an Impinging Jet
,”
ASME Trans. J. Heat Transfer
,
124
(6), pp.
1039
1048
.10.1115/1.1469522
18.
Lee
,
D. H.
,
Park
,
H. J.
, and
Ligrani
,
P. M.
,
2013
, “
Visualization and Structure of Confined, Milliscale, Unsteady Impinging Slot Jets and Associated Vortices
,”
Exp. Fluids
,
54
, pp.
1420
1434
.10.1007/s00348-012-1420-3
19.
Popiel
,
C. O.
, and
Trass
,
O.
,
1992
, “
Visualization of a Free and Impinging Round Jet
,”
Exp. Therm. Fluid Sci.
,
4
(3), pp.
106
115
.10.1016/0894-1777(91)90043-Q
20.
Angioletti
,
M.
,
Di Tommaso
,
R. M.
,
Nino
,
E.
, and
Ruocco
,
G.
,
2003
, “
Simultaneous Visualization of Flow Field and Evaluation of Local Heat Transfer by Transitional Impinging Jets
,”
Int. J. Heat Mass Transfer
,
46
(10), pp.
1703
1713
.10.1016/S0017-9310(02)00479-9
21.
O'Donovan
,
T. S.
, and
Murray
,
D. B.
,
2007
, “
Jet Impingement Heat Transfer—Part II: A Temporal Investigation of Heat Transfer and Local Fluid Velocities
,”
Int. J. Heat Mass Transfer
,
50
(17–18), pp.
3302
3314
.10.1016/j.ijheatmasstransfer.2007.01.047
22.
Fox
,
M. D.
,
Kurosaka
,
M.
,
Hedges
,
L.
, and
Hirano
,
K.
,
1993
, “
The Influence of Vortical Structures on the Thermal Fields of Jets
,”
J. Fluid Mech.
,
255
, pp.
447
472
.10.1017/S0022112093002551
23.
Goodro
,
M.
,
Ligrani
,
P. M.
,
Fox
,
M.
, and
Moon
,
H.-K.
,
2010
, “
Mach Number, Reynolds Number, Jet Spacing Variations: Full Array of Impinging Jets
,”
J. Thermophys. Heat Transfer
,
24
(
1
), pp.
133
144
.10.2514/1.44029
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