The authors have reported that a minichannel flow system had a high heat transfer coefficient. We investigated the heat transfer and flow structure of single and array minichannels combined with an impingement flow system experimentally and numerically. The diameter D of the channel was 1.27mm, and length to diameter ratio LD was 5. The minichannel array was so-called shower head, which was constructed by 19 minichannels located at the apex of equilateral triangle, the side length S of which was 4mm a single stage block was used to investigate the heat transfer without impinging flow system. Two stage blocks were combined in series to compose an impingement heat transfer system with an impingement distance of H. HD ranged from 1.97 to 7.87. The dimensionless temperature increased as the impingement distance became short. A comparison of heat transfer performance was made between minichannel flow and impingement jet by comparing the single- and two-stage heat transfer experiments. It was found that dimensionless temperature of the minichannel exceeded that of the impingement jet. The mechanism of high heat transfer was studied numerically by the Reynolds-averaged Navier-Stokes equation and k-ω turbulence model. The limiting streamline pattern was correlated well to the surface heat flux distribution. The high heat transfer was achieved by suppressing the development of boundary layer under strong pressure gradient near the channel inlet. This heat transfer mechanisms became dominant when the channel size fell into the region of the minichannel.

1.
Hara
,
K.
,
Furukawa
,
M.
, and
Akihiro
,
N.
, 2005, “
Experimental Investigation of Heat Transfer in Square and Circular Minichannel Air Flow for Wide Range of Pressure Ratio
,” ASME Paper No. ICMM2005-75184.
2.
Lee
,
Dh.
,
Song
,
J.
, and
Jo
,
M. C.
, 2004, “
The Effects of Nozzle Diameter on Impinging Jet Heat Transfer and Fluid Flow
,”
ASME J. Heat Transfer
0022-1481,
126
(
4
), pp.
554
557
.
3.
Zuckerman
,
N.
, and
Lior
,
N.
, 2005, “
Impingement Heat Transfer: Correlations and Numerical Modeling
,”
ASME J. Heat Transfer
0022-1481,
127
, pp.
544
552
.
4.
Gillespie
,
D. R. H.
,
Byerley
,
A. R.
,
Ireland
,
P. T.
,
Wang
,
Z.
,
Jones
,
T. V.
,
Kohler
,
S. T.
, 1996, “
Detailed Measurements of Local Heat Transfer Coefficient in the Entrance to Normal and Inclined Film Cooling Holes
,”
ASME J. Turbomach.
0889-504X,
118
, pp.
285
290
.
5.
Goldstein
,
R. J.
, and
Behbahani
,
A. I.
, 1982, “
Impingement of a Circular Jet With and Without Cross Flow
,”
Int. J. Heat Mass Transfer
0017-9310,
25
(
9
),
1377
13829
.
6.
Olsson
,
E. F. M.
,
Ahrne
,
L. M.
,
Tragardh
,
A. C.
, 2004, “
Heat Transfer From a Slot Air Jet Impinging on a Circular Cylinder
,”
J. Food. Eng.
0260-8774,
63
, pp.
393
401
.
7.
Torbidoni
,
L.
, and
Horlock
,
J. H.
, 2005, “
A New Method to Calculate the Coolant Requirements of a High-Temperature Gas Turbine Blade
,”
ASME J. Turbomach.
0889-504X,
127
(
1
), pp.
191
199
.
8.
Castillo
,
L.
, and
Wang
,
X.
, 2004, “
Similarity Analysis for Nonequilibrium Turbulent Boundary Layers
,”
ASME J. Fluids Eng.
0098-2202,
126
(
5
), pp.
827
834
.
9.
De La Calzada
,
P.
, and
Alonso
,
A.
, 2003, “
Numerical Investigation of Heat Transfer in Turbine Cascades With Separated Flows
,”
ASME J. Turbomach.
0889-504X,
125
(
2
), pp.
260
266
.
10.
Siba
,
F. A.
,
Ganesa-Pillai
,
M.
,
Harris
,
K.
, and
Haji-Sheikh
,
A.
, 2003, “
Heat Transfer in a High Turbulence Air Jet Impinging Over a Flat Circular Disk
,”
ASME J. Heat Transfer
0022-1481,
125
(
2
), pp.
257
265
.
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