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ام ا د ا ٢ اد ٢ ٢٠٠٩ ٧٩ : . (Heat sinks) . . (Dissipated) . (31%) . . (0.12%) . : STUDY OF FINS SHAPES' EFFECT ON NATURAL THERMAL CONVECTION Waleed Mohammad Abid Engineering College Anbar University

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Page 1: ˛ 2 - | University Of Al-Qadisiyahqu.edu.iq/engjou/wp-content/uploads/2015/02/15-2-2009.pdf · ٢٠٠٩ ٢ د ا ٢ ا ا م د ا

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STUDY OF FINS SHAPES' EFFECT ON NATURAL THERMAL

CONVECTION

Waleed Mohammad Abid

Engineering College

Anbar University

Page 2: ˛ 2 - | University Of Al-Qadisiyahqu.edu.iq/engjou/wp-content/uploads/2015/02/15-2-2009.pdf · ٢٠٠٩ ٢ د ا ٢ ا ا م د ا

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Abstract: In many electric circuit boards thermally induced buoyancy effects are not always sufficient to

adequately cool high density electronic packages found in modern circuit boards. Instances thermal enhancement techniques, such as heat sinks, must be used to increase the effective surface area for heat transfer so lower the thermal resistance between sources and sink.

Both vertical rectangular and pin finned surfaces were studied to show the shape effect and natural convection heat transfer coefficient. The thermal dissipated from vertical rectangular finned surfaces greater than pins finned surfaces. The overall thermal resistance of the pins finned surfaces greater (31%) compared with vertical rectangular finned surfaces.

An empirical equation was predicted to calculate average natural convection heat transfer coefficient from vertical rectangular and pin fins. The results show an excellent convince with the Literature review where the overall error was about (0.12%).

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!" ����, �H*%�� ����)�( !/ ;I18 ������� * (0.12%).

��#-��: 1. Cengel Y. A. 'HEAT TRANSFER A PRACTICAL APPROACH' McGraw-Hill, Int. 2001.

2. Lienhard IV J. H. and Lienhard V J. H. 'A HEAT TRANSFER TEXTBOOK' Third ed. Cambridge, MA: Phlogiston Press, 2006.

3. Elenbass W. 'HEAT DISSIPATION OF PARALLEL PLATES BY FREE CONVECTION' Physical, Vol. 9, No.1,1942.

4. Van de pol D. W. and Tiemey J. K. ' FREE CONVECTION NUSSELT NUMBER FOR

VERTICAL U-SHAPED CHAMELS' J. of Heat Transfer, Vol. 95, 1973. 5. Welling J. R. and Wooldridge C. B. ' FREE CONVECTION HEAT TRANSFER

COEFFICIENTS FROM RECTANGULAR VERTICAL FINS' J. of Heat Transfer, Vol. 87, 1965.

6. Jones C. D. and Smith L.F. 'OPTIMUM ARRANGEMENT OF RECTANGULAR FINS ON

HORIZONTAL SURFACES FOR FREE CONVECTION HEAT TRANSFER' J. of Heat Transfer, Vol. 92, 1970.

7. Garg V. K. and Velusamy K. ' HEAT TRANSFER CHARACTERISTICS FOR A PLATE

FIN ' J. of Heat Transfer, Vol. 108, 1986. 8. Culham J. R. , Yovanovich M. M. and Lee S. 'THERMAL MODELLING OF

ISOTHERMAL CUBOIDS AND RECTANGULAR HEAT SINKS COOLED BY NATURAL

CONVECTION' IEEE Transaction on components, Packaging, and Manufacturing Technology-part A, Vol. 18, 1995.

9. Yovanovich M. M., Teertstra P., and Culham J. R. ' NATURAL CONVECTION

MODELLING OF HEAT TRANSFER SINKS USING WEB-BASED TOOLS. www.electronics-coollingcom/html/2000-sep-a4.html,2004.

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