0
THERMAL ISSUES IN EMERGING TECHNOLOGIES

Convective Heat Transfer in Graphite Foam Heat Sinks With Baffle and Stagger Structures

[+] Author and Article Information
K. C. Leong1

School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singaporemkcleong@ntu.edu.sg

H. Y. Li, L. W. Jin

School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore

J. C. Chai

Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi, United Arab Emirates

1

Corresponding author.

J. Heat Transfer 133(6), 060902 (Mar 04, 2011) (9 pages) doi:10.1115/1.4003449 History: Received November 10, 2009; Revised February 04, 2010; Published March 04, 2011; Online March 04, 2011

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.

FIGURES IN THIS ARTICLE
<>
Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Typical internal structure of Poco graphite foam of 75% porosity

Grahic Jump Location
Figure 2

Configurations of (a) baffle and (b) stagger structures

Grahic Jump Location
Figure 3

(a) Experimental facility and (b) cross-sectional view of test section

Grahic Jump Location
Figure 4

Schematic diagram of physical system

Grahic Jump Location
Figure 5

Pressure drop versus inlet flow velocity in tested graphite foams

Grahic Jump Location
Figure 6

Comparison of numerical and experimental local Nusselt numbers in (a) block, (b) stagger, and (c) baffle structures

Grahic Jump Location
Figure 7

Pumping power versus length-averaged Nusselt number in block, baffle, and stagger foams

Grahic Jump Location
Figure 8

(a) Top view and (b) velocity distribution in block graphite foam

Grahic Jump Location
Figure 9

(a) Top view and (b) velocity distribution in baffle foam; (c) top view and (d) velocity distribution in stagger graphite foam

Grahic Jump Location
Figure 10

(a) Surface and (b) slice temperature distributions in block foam at Re=40

Grahic Jump Location
Figure 11

(a) Surface and (b) slice temperature distributions in stagger foam at Re=26

Grahic Jump Location
Figure 12

(a) Surface and (b) slice temperature distributions in baffle foam at Re=32

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In