Highly conductive porous media have recently been considered for enhanced cooling applications due to their large internal contact surface area, which promotes convection at the pore level. In this paper, graphite foams that possess high thermal conductivity but low permeability are investigated for convection heat transfer enhancement using air as coolant. Two novel heat sink structures are designed to reduce the fluid pressure drop. Both experimental and numerical approaches are adopted in the study. The experimental data show that the designed structures significantly reduce flow resistance in graphite foams while maintaining relatively good heat removal performance. The numerical results obtained based on the local thermal nonequilibrium model are validated by experimental data and show that the inlet air flow partially penetrates the structured foam walls, while the remaining air flows tortuously through slots in the structure. Flow mixing, which is absent in the block graphite foam, is observed in the freestream area inside the designed structure. It can be concluded that graphite foams with appropriately designed structures can be applied as air-cooled heat sinks in thermal management applications.

1.
Bhattacharya
,
A.
,
Calmidi
,
V. V.
, and
Mahajan
,
R. L.
, 2001, “
Thermophysical Properties of High Porosity Metal Foams
,”
Int. J. Heat Mass Transfer
0017-9310,
44
, pp.
827
836
.
2.
Fu
,
H. L.
,
Leong
,
K. C.
,
Huang
,
X. Y.
, and
Liu
,
C. Y.
, 2001, “
An Experimental Study of Heat Transfer of a Porous Channel Subjected to Oscillating Flow
,”
ASME J. Heat Transfer
0022-1481,
123
, pp.
162
170
.
3.
Bhattacharya
,
A.
, and
Mahajan
,
R. L.
, 2002, “
Finned Metal Foam Heat Sinks for Electronics Cooling in Forced Convection
,”
ASME J. Electron. Packag.
1043-7398,
124
, pp.
155
163
.
4.
Boomsma
,
K.
,
Poulikakos
,
D.
, and
Zwick
,
F.
, 2003, “
Metal Foams as Compact High Performance Heat Exchangers
,”
Mech. Mater.
0167-6636,
35
, pp.
1161
1176
.
5.
Leong
,
K. C.
, and
Jin
,
L. W.
, 2005, “
An Experimental Study of Heat Transfer in Oscillating Flow Through a Channel Filled With an Aluminum Foam
,”
Int. J. Heat Mass Transfer
0017-9310,
48
, pp.
243
253
.
6.
Klett
,
J. W.
, 2000, “
Process for Making Carbon Foam
,” U.S. Patent No. 6,033,506.
7.
Klett
,
J. W.
,
Hardy
,
R.
, and
Romine
,
E.
, 2000, “
High Thermal Conductivity, Mesophase-Pitch-Derived Carbon Foam: Effect of Precursor on Structure and Properties
,”
Carbon
0008-6223,
38
, pp.
953
973
.
8.
Klett
,
J. W.
,
McMillan
,
A. D.
,
Gallego
,
N. C.
, and
Walls
,
C. A.
, 2004, “
The Role of Structure on Thermal Properties of Graphitic Foams
,”
J. Mater. Sci.
0022-2461,
39
, pp.
3659
3676
.
9.
Ott
,
R. D.
,
Zaltash
,
A.
, and
Klett
,
J. W.
, 2002, “
Utilization of a Graphite Foam Radiator on a Natural Gas Engine-Driven Heat Pump
,”
Proceedings of the IMECE 2002 ASME International Mechanical Engineering Conference and Exposition
, New Orleans, LA, Nov. 17–22.
10.
Straatman
,
A. G.
,
Gallego
,
N. C.
,
Thompson
,
B. E.
, and
Hangan
,
H.
, 2006, “
Thermal Characterization of Porous Carbon Foam—Convection in Parallel Flow
,”
Int. J. Heat Mass Transfer
0017-9310,
49
, pp.
1991
1998
.
11.
Straatman
,
A. G.
,
Gallego
,
N. C.
,
Yu
,
Q.
, and
Thompson
,
B. E.
, 2007, “
Characterization of Porous Carbon Foam as a Material for Compact Recuperators
,”
ASME J. Eng. Gas Turbines Power
0742-4795,
129
, pp.
326
330
.
12.
Gallego
,
N. C.
, and
Klett
,
J. W.
, 2003, “
Carbon Foams for Thermal Management
,”
Carbon
0008-6223,
41
, pp.
1461
1466
.
13.
Williams
,
Z. A.
, and
Roux
,
J. A.
, 2006, “
Graphite Foam Thermal Management of a High Packing Density Array of Power Amplifiers
,”
ASME J. Electron. Packag.
1043-7398,
128
, pp.
456
465
.
14.
Taylor
,
J. R.
, 1997,
An Introduction to Error Analysis
,
2nd ed.
,
University Science Books
,
Sausalito, CA
.
15.
Hsu
,
C. T.
, and
Cheng
,
P.
, 1990, “
Thermal Dispersion in a Porous Medium
,”
Int. J. Heat Mass Transfer
0017-9310,
33
, pp.
1587
1597
.
16.
Tee
,
C. C.
,
Klett
,
J. W.
,
Stinton
,
D. P.
, and
Yu
,
N.
, 1999, “
Thermal Conductivity of Porous Carbon Foam
,”
Proceedings of the 24th Biennial Conference on Carbon
, Charleston, SC, Jul. 11–16.
17.
Yu
,
Q. J.
,
Thompson
,
B. E.
, and
Straatman
,
A. G.
, 2006, “
A Unit Cube-Based Model for Heat Transfer and Fluid Flow in Porous Carbon Foam
,”
ASME J. Heat Transfer
0022-1481,
128
, pp.
352
360
.
18.
Klett
,
J. W.
,
McMillan
,
A. D.
, and
Stinton
,
D.
, 2002, “
Modeling Geometric Effects on Heat Transfer With Graphite Foam
,”
26th Annual Conference on Ceramic, Metal, and Carbon Composites, Materials, and Structures
, Cocoa Beach, FL.
19.
Vafai
,
K.
, and
Thiyagaraja
,
R.
, 1987, “
Analysis of Flow and Heat Transfer at the Interface Region of a Porous Medium
,”
Int. J. Heat Mass Transfer
0017-9310,
30
, pp.
1391
1405
.
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