Research Papers

Effect of a Slotted Shield on Thermal and Hydraulic Performance of a Heat Sink

[+] Author and Article Information
Mohamed L. Elsayed

Mechanical Power Engineering Department,
Faculty of Engineering,
Zagazig University,
Sharkia 44519, Egypt
e-mail: mlabdelkrem@zu.edu.eg

Osama Mesalhy

Mechanical Power Engineering Department,
Faculty of Engineering,
Zagazig University,
Sharkia 44519, Egypt
e-mail: mesalhy_osa@yahoo.com

1Corresponding author.

Contributed by the Electronic and Photonic Packaging Division of ASME for publication in the JOURNAL OF ELECTRONIC PACKAGING. Manuscript received December 24, 2013; final manuscript received June 19, 2014; published online October 6, 2014. Assoc. Editor: Pradip Dutta.

J. Electron. Packag 137(1), 011004 (Oct 06, 2014) (6 pages) Paper No: EP-13-1140; doi: 10.1115/1.4027920 History: Received December 24, 2013; Revised June 19, 2014

The attachment of a shield to a heat sink enhances the thermal performance. But, forming slots in the shield increases thermal resistance. We found that increasing the slot width enhances the flow performance over the heat sink and this improvement continues as the number of slots increases, but the thermal performance, on the other hand, decreases. Slots work as a flow bypass and create jets to destroy eddies and vortices created by the shield. Therefore, pressure drop at Re = 55,000 for a slotted case is about 80% lower than a solid shield. For suitable thermal resistance and moderate pressure drop, the appropriate slotted shield will have 3–7 slots at different slot widths. These slots preserve the improvement of thermal resistance with a suitable pressure drop.

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Fig. 1

Boundary conditions for heat sink with a slotted heat shield

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Fig. 2

Comparison of simulation with experimental data at different inclination angles by [20]

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Fig. 3

Velocity contours, streamlines, pressure, and temperature contours at section A-A

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Fig. 4

Effect of Reynolds number on pressure drop across heat sink (number of fins N = 16)

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Fig. 5

Effect of fin height to channel height on pressure drop across the heat sink (number of fins N = 16)

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Fig. 6

Variation of thermal enhancement factor η with different ReDh, β, and the slot width




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