(3.210.184.142) 您好!臺灣時間:2021/05/16 02:59
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果

詳目顯示:::

我願授權國圖
: 
twitterline
研究生:潘金鳳
研究生(外文):Chin-Feng Pan
論文名稱:渠道內具加熱凸塊流場與熱對流傳輸之研究
論文名稱(外文):Flow and Convective Heat Transfer Analysis of Heated Blocks in a channel
指導教授:楊德良楊德良引用關係
指導教授(外文):Der-Liang Young
學位類別:碩士
校院名稱:國立臺灣大學
系所名稱:土木工程學研究所
學門:工程學門
學類:土木工程學類
論文種類:學術論文
論文出版年:2004
畢業學年度:92
語文別:英文
論文頁數:51
中文關鍵詞:奈維爾-史托克斯方程式渦流區溫度分布具單一或多加熱凸塊的渠流
外文關鍵詞:eddy zonesNavier-Stokes equationstemperature distributionchannel flow with single and multiple solid blocks
相關次數:
  • 被引用被引用:1
  • 點閱點閱:74
  • 評分評分:
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
近年來,隨著個人電腦趨於輕薄短小及增加大量高速運算功能,使得電子元件的冷卻在計算流體領域中為一極熱門的問題。為了維持機器正常的運作,我們必須有效率持續性地將從電子零件中產生的熱移除。有鑑於此,許多學者致力於研究電腦的冷卻問題,去探討影響流體及熱對流傳輸的參數。在本論文中,將以渠道內加熱凸塊的數值運算去模擬印刷電路版和散熱片的冷卻問題。在此先以單一和三個成直線排列及四個、六個和十個成交錯排列的突出物去探討熱對流傳輸及流況現象。本文的數值模式為二維黏性不可壓縮具熱對流的奈維爾-史托克斯方程式,以主要參數的形式表示。

模擬結果顯示在不同具突出物的渠流中,其下游段皆會產生渦流,並能貼切的描述在凸塊端點熱邊界層的發展。於本研究之結果中可以看出不同個數及大小的凸塊,對流線、速度向量及溫度場的影響,並顯示出其下游不受影響的範圍。
Numerical analysis of cooling of electronic components is a hot research topic in the field of computational fluid dynamics due to its importance in the development of miniature size computers as well as in achieving high speed computation on desk top computers. The heat generated by the various electronic components has to be continuously removed for the efficient and continuous operation of the equipment. The advancement in high speed computing as well as the development of flow algorithms has enabled the researchers to compute the flow and heat transfer parameters for the design of cooling systems for computers. Numerical analysis of electronic cooling can be modeled by analyzing a channel with a number of solid blocks in the channel. The system is represented by the two-dimensional Navier-Stokes equations and the energy equation. In the present work an attempt is made to model the cooling of printed circuit board (PCB) and heat sinks by simulating channel flows in the presence of single, three, four, six and ten solid blocks. Two dimensional Navier-Stokes equations in primitive variable form have been solved using the finite element method.

Simulation results for different channel flow cases with the solid blocks indicate the formation of eddy zones at the downstream region of the solid blocks. The development of thin thermal boundary layers at the leading edge of the solid blocks is correctly predicted in the present work. The effect of the presence of number of solid blocks on the flow field as well as on the temperature fields are plotted in the form of streamline patterns, velocity vector distributions and temperature contours in the channel. The eddy zones formed at the downstream sides of the solid blocks reduce the convective heat transfer due to the discontinuity in the temperature profiles. The present numerical model could predict the effect of number of solids in the channel on the length taken by the fluid to become uniform at the downstream side of the channel.
誌謝 i
摘要 ii
Abstract iii
Table of Contents iv
List of Figures vi
Symbols vii

Chapter 1 Introduction 1
1.1 Introduction 1
1.2 Air cooling of electronic components 2
1.3 Types of heat transfer 2
1.4 Conjugate heat transfer 3
1.5 Objectives of the present work 4
1.6 Literature review 5
1.6.1 Heat transfer problem 5
1.6.2 Numerical schemes 6
1.7 Organization of thesis 7

Chapter 2 Mathematical formulation 8
2.1 Governing equations 8
2.2 Initial conditions 11
2.3 Boundary conditions 12

Chapert 3 Numerical analysis 14
3.1 Projection method 14
3.2 Time discretization 16
3.3 Spatial discretization 18
3.4 Solution of algebraic governing equations 21

Chapter 4 Results and Discussion 23
4.1 Introduction 23
4.2 Channel with a single solid block 23
4.3 Channel with three solid blocks 27
4.4 Channel with four solid blocks 30
4.5 Channel with six solid blocks 34
4.6 Channel with ten solid blocks 37
4.7 Nusselt number 40

Chapter 5 Conclusions and scope for future work 43
5.1 Main conclusions 43
5.2 Scope for future work 45

References 46
Appendix 50
1. R. Iwatsu, J. M. Hyun, K. Kuwahara, Mixed convection in a driven cavity with a stable vertical temperature gradient, International Journal of Heat and Mass Transfer, 1993;36,1601-1608.
2. H. F. Oztop, I. Dagtekin, Mixed convection in two-sided lid-driven differentially heated square cavity, International Journal of Heat and Mass Transfer, 2004;47,1761-1769.
3. K. H. Kim, J. M. Hyun, H. S. Kwak, Buoyant convection in a side-heated cavity under gravity and oscillations, International Journal of Heat and Mass Transfer, 2001;44,857-861.
4. X. shi, J. M. Khodadadi, Laminar Fluid Flow and Heat Transfer in a Lid-Driven Cavity Due to a Thin Fin, Journal of Heat Transfer, 2002;124,1056-1063.
5. J. Davalath, Y. Bayazitoglu, Forced Convection Cooling Across Rectangular Block, Journal of Heat Transfer. 1987;109,321-328.
6. T. J. Young, K. Vafai, Convective Cooling of a Heated Obstacle in a Channel, International Journal of Heat and Mass Transfer, 1998;41,3131-3148.
7. S. Y. Kim, H. J. Sung, J. M. Hyun, Mixed Convection from Multiple-Layered Boards with Cross-Streamwise Periodic Boundary Conditions, International Journal of Heat and Mass Transfer, 1992;35,2941-2952.
8. G. Desrayaud, A. Fichera, On Natural Convective Heat Transfer in Vertical Channels With a Single Surface Mounted Heat-Flux Module, Journal of Heat Transfer; 2003;125,735-739.
9. K. Boulama, N. Galanis, Analytical Solution for Fully Developed Mixed Convection Between Parallel Vertical Plates With Heat and Mass Transfer, Journal of Heat Transfer, 2004;126,381-388.
10. J. Orfi, N. Galanis, C. T. Nguyen, Bifurcation in Steady Laminar Mixed Convection Flow in Uniformly Heated Inclined Tubes, International Journal of Numerical Methods for Heat and Fluid Flow, 1999;9,543-567.
11. A. Baletta, E. Zanchini, On the choice of the Reference Temperature for Fully-Developed Mixed Convection in a Vertical Channel, International Journal of Heat and Mass Transfer, 1999;42,3169-3181.
12. K. Ramakrishna, S. G. Rubin, P. K. Khosla, Laminar Natural Convection Along Vertical Square Ducts, Numerical Heat Transfer;1982,5,59-79.
13. J. Orfi, N. Galanis, C. T. Nguyen, Laminar Mixed Convection in the Entrance Region of Inclined Pipes with High Uniform Heat Fluxes, ASHRAE Transactions, 1998;104,417-428.
14. M. He, A. J. Kassab, P. J. Bishop, A. Minardi, An Iterative FDM/BEM method for the Conjugate Heat Transfer Problem --- Parallel Plate Channel With Constant Outside Temperature, Engineering Analysis with Boundary Elements, 1995;15,43-50.
15. A. Haji-Sheikh, Estimation of Average and Local Heat Transfer in Parallel Plates and Circular Ducts Filled With Porous Materials, Journal of Heat Transfer, 2004;126,400-409.
16. J. Orfi, N. Galanis, Developing Laminar Mixed Convection With heat and Mass Transfer in Horizontal and Vertical tubes, International Journal of Thermal Sciences, 2002;41,319-331.
17. Adrian Bejan, Optimal Internal Structure of Volumes Cooled by Single-Phase Forced and Natural Convection, Journal of Electronic Packaging, 2003;125,200-207.
18. Manish Mishra, P. K. Das, Sunil Sarangi, Transient Behavior of Crossflow Heat Exchangers With Longitudinal Conduction and Axial Dispersion, Journal of Heat Transfer, 2004; 126, 425-433.
19. Christophe Marques, Kevin W. Kelly, Fabrication and Performance of a Pin Fin Micro Heat Exchanger, Journal of Heat Transfer, 2004;126,434-444.
20. Shyy Woei Chang, Lo May Su, Tsun Lirng Yamg, Shyr Fun Chiou, Enhanced Heat Transfer of Forced Convective Fin Flow With Transverse Ribs, International Journal of Thermal Sciences, 2004;43, 185-200.
21. T. –M. Liou, J. –J. Hwang, Turbulent Heat Transfer Augmentation and Friction in Periodic Fully Developed Channel Flows, Journal of Heat Transfer, 1992; 114,56-64.
22. J. C. Han, Y. M. Zhang, C. P. Lee, Augmented Heat Transfer in Square Channels With Parallel, Crossed, and V-Shaped Angled Ribs, Journal of Heat Transfer, 1991;113,590-596.
23. S. Mochizuki, A. Murata, M. Fukunaga, Effects of Rib Arrangements on Pressure Drop and Heat Transfer in a Rib-Roughened Channel With A sharp 180 deg Turn, Journal of Turbomachinery,1996;119,610-616.
24. M. E. Taslim, T. Li, D. M. Kercher, Experimental Heat Trandfer and Friction in Channels Roughened With Angled,V-Shaped, and Discrete Ribs on Two Opposite Walls, Journal of Turbomachinery,1996;118,20-28.
25. S. Sathe, B. Sammakia, A Review of Recent Developments in Some Practical Aspects of Air-Cooled Electronic Packages, Journal of Heat Transfer,1998;120,830-839.
26. G.. Ledsma, A. M. Morega, A. Bejan, Optimal Spacing Between Pin Fins With Impinging Flow, Journal of Heat Transfer, 1996;118,570-577.
27. R. Fehle, J. Klas, F. Mayinger, Investigation of Local Heat Transfer in Compact Heat Exchangers by Holographic Interferometry, Experimental Thermal and Fluid Science, 1993;10,181-191.
28. Bijan Farhanieh, Cila Herman, Bengt Sunden, Numerical and Experimental Analysis of Laminar fluid flow and Forced Convection Heat Transfer in a Grooved Duct, International Journal of Heat and Mass Transfer, 1993;36,(6),1609-1617.
29. Roy, W. Knight, Donals J. Hall, John S. Goodling,Richard C. Jarger,Heat Sink Opimization with Application to Microchannels, IEEE Transactions on Components, Hybrids and Manufacturing Technology, 1992;15,(5),832-842.
30. D. A. Aliaga, J. P. Lamb, D. E. Klein, Convection heat transfer distributions over plates with Square ribs from infrared thermography measurements, International Journal of Heat and Mass Transfer, 1994;37,363-374.
31. Octavio Leon, Gilbert De Mey, Erik Dick, Jan Vierendeeles, Comparison Between the Standard and Staggered Layout for Cooling Fins in Forced Convection Cooling, Journal of Electronic Packaging,2003;125,442-446.
32. F. H. Harlow, J. E. Welch, Numerical Calculation of Time-Dependent Viscous Incompressible Flow of Fluids With Free Surface, Physics of Fluids, 1965;8,2182-2189.
33. A. J. Chorin, A numerical Method for Solving Incompressible Viscous Flow Problems, Journal of Computational Physics, 1967;2,12-26.
34. A. J. Chorin, J. E. Marsden, A Mathematical Introduction to Fluid Mechanics, Springer, 1993,third Edition.
35. E. Weinan, J. G. Liu, Projection Method 1: Convergence and Numerical Boundary Layers, SIAM. Journal Numerical Analysis, 1995;32,1017-1057.
36. L. S. Caretto, A. D. Gosman, S. V. Pantankar, D. Spalding, Two Calculational Procedures for Steady, Three–Dimensional Flows with Recirculation, Proc. Third. Int. Conf. Num. Methods Fluid Mech., Lect. Notes Phys.,19,Springer-Verlag, New York,1972,60-68.
37. Q. H. Lin, Finite Element Analysis of Hydrodynamic Flow with Moving Boundaries, PhD thesis, National Taiwan University 1992.
38. D.L.Young, Q.H.Lin, Finite Element Modeling of Reservoir Dynamics, Proceedings of 22th Congress of IAHR, Lausanne, Switzerland, Technical Session, C1,1987,76-80.
39. D.L.Young, Q.H.Lin, Modeling Thermally Stratified Lakes with Free Surfaces, Proceedings of 23th Congress of IAHR, Lausanne, Ottawa, Canada, Technical Session, C1,1989 D,137-144.
40. D.L.Young, Q.H.Lin, Numerical Simulation of the Unsteady Density Current in Reservoir, in Water Management of the Amazon Basin, ed. By B.P.E. Braga Jr. and C.A. FERNANDEZ-Jauregui, UNESCO,1991,153-162.
41. D.L.Young,Q.H.Lin, Density Currents during a Storm in Te-Chi Reservoir of Taiwan, Proceedings of 24th Congress of IAHR,Madrid,Spain,Technical Session A,1991,801-810.
42. Philip M. Gresho, Steven T.Chen, Robert L. Lee, Craig D.Upson, A modified Finite Element Method for Solving the Time-Dependent, Incompressible Navier-Stokes Equations. Part 1:Theory, International Journal for Numerical Method in Fluids,1984;4,557-598.
43. J. K. Dukowicz, J. D. Ramshaw, Tensor Viscosity Method for Convection in Numerical Fluid Dynamics, Journal of Computational Physics,1979;32,71-79.
44. P. Roache, T. Mueller, Numerical solutions of laminar separated flows, AIAA Journal, 1970;8,530-538.
45. LM. Leone, PM. Gresho, Finite element simulation of steady, two dimensional, viscous incompressible flow over a step, Journal of Computational Physics, 1981;41,167-191.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top