跳到主要內容

臺灣博碩士論文加值系統

(3.235.140.84) 您好!臺灣時間:2022/08/13 05:36
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

: 
twitterline
研究生:許國偉
研究生(外文):Kao-Wei Hsu
論文名稱:強制脈衝流動配合多孔性熱沉於電子元件冷卻之探討
論文名稱(外文):Numerical Study of Heat Transfer Enhancement with Porous Heat Sink in the Pulsating Channel Flow
指導教授:黃仁智黃仁智引用關係黃博全黃博全引用關係
指導教授(外文):Jen-Jyh HwangPo-CHuan Huang
學位類別:碩士
校院名稱:國立中山大學
系所名稱:機械與機電工程學系研究所
學門:工程學門
學類:機械工程學類
論文種類:學術論文
論文出版年:2002
畢業學年度:90
語文別:中文
論文頁數:91
中文關鍵詞:多孔行熱沉脈衝流散熱增強達西數
外文關鍵詞:Darcy numberCooling enhancementPulsating flowPorous heat sink
相關次數:
  • 被引用被引用:1
  • 點閱點閱:203
  • 評分評分:
  • 下載下載:39
  • 收藏至我的研究室書目清單書目收藏:0
本文以數值方法探討在強迫脈衝流利用多孔質熱沉對平行板道內矩形發熱元件列之散熱熱傳增強特性。文以Darcy-Brinkman-Forchheimer流動模式,來模擬多孔性結構內部的流場狀態,而純流體區內之流動則採遵守Navier-Stoke方程式。結合界面條件以流線函數-渦度轉換式及使用控制體積法與混合法則求解上述流體/多孔質/固體複合層之藕合方程組。藉由各項參數變換,包括雷諾數Re、達西數Da、頻率參數St、振幅參數A和幾何參數(熱沉間隔Sp*),來探討流場之變化及其對熱傳增強的影響。數值運算結果,獲得在週期性穩定狀態後,廣範圍之瞬間流線場及等溫線場。其結果顯示,在脈衝流下由具多孔質熱沉之發熱元件所引起位於兩元件間之週期性縮小膨漲之循環渦流區的大小及強度主控著元件散熱冷卻的增強效益。而此種熱傳增強效果會隨著雷諾數、頻率參數、振幅參數增加而增加;但隨達西數增加而減小。至於熱沉間隔,在適當的範圍內可達增強對流熱傳的效果。此外,在與穩定非脈衝流且無多孔質熱沉元件比較,利用脈衝流配合多孔質熱沉應用,發熱元件有顯著的散熱增強,且元件瞬間運作之最大溫度均呈現降低趨勢。
A numerical study was carried out for enhanced heat transfer from two heated blocks in a pulsating channel flow by porous heat sink. The flow over the fluid region is governed by the Navier-Stokes equation, and the flow through the porous medium is governed by the Darcy-Brinkman-Forchheimer equation. These two flows are coupled through the interface boundary conditions at the porous/fluid and porous/solid interfaces. After a stream function-vorticity transformation, solution of the coupled governing equations for fluid/porous/solid composite system is obtained using the control-volume-based procedure and hybrid scheme. Comprehensive time-dependent flow and temperature data obtained and averaged over a cycle of pulsation in a periodic steady state. In addition, this study details the effects of variation in the governing parameters, such as inertia parameter, Dracy number, Reynolds number, Strouhal number, pulsation amplitude and geometric parameters, to illustrate important fundamental and practical results. The results show that the periodic change of shape of interblock recirculation flow caused by porous-covering blocks has significant enhanced effect on flow pattern and heat transfer characteristics. This enhanced effect is found to increase with Reynolds number, Strouhal number and pulsation amplitude but decrease with Dracy number. In comparison with the non-porous heat sink case for a steady non-pulsating flow, significant increases in the average Nusselt number are predicted and the instantaneous maximum temperatures within the heated block array are reduced. Moreover, it is shown that specific choices in certain geometric parameters, such as interblock space, can make pronounded change in the cooling of heated block.
摘 要I
目 次III
圖目錄V
表目錄IX
第一章 緒論1
1-1前言1
1-2文獻回顧2
1-3 研究目的4
第二章 理論分析5
2-1 基本假設6
2-2 系統方程式及起始∕邊界條件7
2-2 統御方程式無因次化11
2-4 紐賽數(Nusselt Number)14
2-4.1 局部瞬間紐賽數(Time—local Nusselt number)14
2-4.2 平均紐賽數(Average Nusselt number)14
第三章 數值分析15
3-1 ψ之差分方程式16
3-2多孔性結構與流體界面20
3-3 低鬆弛係數(Under-relaxation)22
3-4 求解步驟23
第四章 結果與討論25
4-1 數值評估25
4-1.1 網格獨立29
4-1.2 數值驗證 (Validation)32
4-2多孔性熱沉所引起之速度與溫度變化35
4-3 達西數Da之影響44
4-4 雷諾數Re之影響53
4-5 頻率參數之影響62
4-6 振幅參數之影響71
4-7多孔質熱沉間隔變化之影響79
第五章 綜合結論88
參考文獻89
圖目錄
圖2-1兩平行板內具多孔性熱沉之發熱元件的物理模型5
圖3.1為二維座標之控制體積示意圖15
圖3.2 數值運算流程圖24
圖4.1 Re=500,DA=3×10-5,Λ=0.35,St=0.4,A=0.2之(a)橫向速度隨時間變化;(b)縱向速度隨時間變化26
圖4.2 Re=500,DA=3×10-5,Λ=0.35,St=0.4,A=0.2之(a)橫向速度隨時間變化;(b)縱向速度隨時間變化27
圖4.3 Re=500,DA=3×10-5,Λ=0.35,St=0.4,A=0.2之(a)橫向速度隨時間變化;(b)縱向速度隨時間變化28
圖4.4 (a)計算區域之格點系統;(b)靠近熱源陣列區之局部放大之格點系統。30
圖4.5 格點獨立31
圖4.6 ( )本文與(---)Kim et al.【14】數值計算結果之比較:Da=10-4 (a) St=0.006 (b) St=0.3233
圖4.7本文(1)與(2)Kim et al.【15】於非脈衝流(A=0), Re=500, Pr=0.7數值計算結果之比較:(a)流線場;(b)等溫線場34
圖4.8 達西數Da=3×10-5時之流道內流線場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)40
圖4.9 達西數Da=3×10-5時之流道內速度場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)41
圖4.10 達西數Da=3×10-5時之流道內溫度場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)42
圖4.11 具多孔質熱沉之發熱元件列於二維平行流道強迫對流數值分析(a)流線場;(b)溫度場。43
圖4.12 無多孔質熱沉之發熱元件列於二維平行流道強迫對流數值分析(a)流線場;(b)溫度場。43
圖4.14 達西數Da=3×10-5時之流道內流線場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)46
圖4.15 達西數Da=3×10-5時之流道內溫度場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)47
圖4.16 達西數Da=9×10-5時之流道內流線場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)48
圖4.17 達西數Da=9×10-5時之流道內溫度場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)49
圖4.18 達西數Da=5×10-4時之流道內流線場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)50
圖4.19 達西數Da=5×10-4時之流道內溫度場隨時間之變化(Re=500;Λ=0.35;St=0.4;A=0.2)51
圖4.20 不同達西數Da之流道內總平均紐賽數變化52
圖4.21 雷諾數Re=500時之流道內流線場隨時間之變化(Da=3×10-5;Λ=0.35;St=0.4;A=0.2)55
圖4.22 雷諾數Re=500時之流道內溫度場隨時間之變化(Da=3×10-5;Λ=0.35;St=0.4;A=0.2)56
圖4.23 雷諾數Re=850時之流道內流線場隨時間之變化(Da=3×10-5;Λ=0.35;St=0.4;A=0.2)57
圖4.24 雷諾數Re=850時之流道內流線場隨時間之變化(Da=3×10-5;Λ=0.35;St=0.4;A=0.2)58
圖4.25 雷諾數Re=1500時之流道內流線場隨時間之變化(Da=3×10-5;Λ=0.35;St=0.4;A=0.2)59
圖4.26 雷諾數Re=1500時之流道內流線場隨時間之變化(Da=3×10-5;Λ=0.35;St=0.4;A=0.2)60
圖4.27 不同雷諾數Re之流道內總平均紐賽數變化61
圖4.28 頻率參數St=0.4時之流道內流線場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;A=0.2)64
圖4.29 頻率參數St=0.4時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;A=0.2)65
圖4.30 頻率參數St=0.8時之流道內流線場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;A=0.2)66
圖4.31 頻率參數St=0.8時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;A=0.2)67
圖4.32 頻率參數St=1.6時之流道內流線場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;A=0.2)68
圖4.33 頻率參數St=1.6時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;A=0.2)69
圖4.34 不同頻率參數St之流道內總平均紐賽數變化70
圖4.35 振幅參數A=0.2時之流道內速度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)72
圖4.36 振幅參數A=0.2時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)73
圖4.37 振幅參數A=0.5時之流道內速度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)74
圖4.38 振幅參數A=0.5時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)75
圖4.39 振幅參數A=0.7時之流道內速度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)76
圖4.40 振幅參數A=0.7時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)77
圖4.41 不同振幅參數A之流道內總平均紐賽數變化78
圖4.42 不同熱沉間隔Sp*=0.5時之流道內速度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)81
圖4.43 不同熱沉間隔Sp*=0.5時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)82
圖4.44 不同熱沉間隔Sp*=1.0時之流道內速度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)83
圖4.45 不同熱沉間隔Sp*=1.0時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)84
圖4.46 不同熱沉間隔Sp*=1.5時之流道內速度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)85
圖4.47 不同熱沉間隔Sp*=1.5時之流道內溫度場隨時間之變化(Da=3×10-5;Re=500;Λ=0.35;St=0.4)86
圖4.48 不同熱沉間隔Sp*之流道內總平均紐賽數變化87
表目錄
表4.1不同網格系統下總平均紐賽數列表31
表4.2各參數的主要變化範圍35
1.Kraus, A. D. and Bar-Cohen, A., Thermal Analysis and Control of Electronic Equipment. Hemisphere, New York, 1983.2.Sparrow, E. M. , Yanezmoreno, A. A. and Otis, D. R. Jr., “Convection Heat Transfer Response to Height Differences in an Array of Block-Lone Electronic Components,” Int.J.Heat Mass Transfer, Vol.27(1984),pp. 469-473.3.Incropera, F. P. , Kerby, J. S. , Moffatt D. F. and Ramadhyani, S., “ Convection Heat Transfer from Discrete Heat Sources in a Rectangular Channel,” Int.J.Heat Mass Transfer, Vol.29(1986),pp. 1051-1058.4.Davalath, J. and Bayazitoglu, Y., “Forced Convection cooling across rectangular blocks,” J. Heat Transfer, Vol.109(1987), pp. 321-328.5.Kang , B.H. , Jaluria , Y. and Tewari , S.S. , “Mixed convection transport from an isolated heat source module on a horizontal plate,” Transactions of the ASME Journal of Heat Transfer , 1990 , 112 , 653-661.6.Kim , S. Y. , Sung , H. J. and Hyun , J. M. , “Mixed convection from multiple-layered boards with cross-streamwise periodic boundary conditions,” International Journal of Heat Mass Transfer. 1992, 35, 2941-2952.7.R. Siegel and M. Perlmutter, “Heat transfer for pulsating laminar duct flow, Transactions of the ASME Journal of Heat Transfer ,” 1962, 84 , 111-123.8.U . H. Kurzweg, “Enhanced heat conduction in oscillating viscous flows within parallel-plane channels,” J. Fluid Mech.1985, 156, 291-300. 9.Kim S. Y. ,Kang B. H. and HYUN J. M. ,”Heat transfer in the thermally developing region of a pulsating channel flow,” Int. J. Heat Mass Transfer, Vol. 36. 4257-4266, 1993.10.Kaviang, M., ”Laminar Flow through a Porous Channel Bounded by Isothermal Parallel Plates” Int.J.Heat and Mass Transfer, Vol.28, pp.851-858,1985.11.Poulikakos, D., and Renhen, K., ”Forced Convection in a Channel Filled with Porous Medium, Including the Brinkman Friction, ”.J. Heat Transfer,ASME, Vol.109, pp.880-888,1987.12.Channabasappa, K. G. Umapathy and Nayak, I. V., ”Convection Heat Transfer in a Parallel Plate Channel with Porous Lining, ” Warme-und Stoffubertragung., 17,pp.211-226,1983.13.Huang, P. C. and Vafai, K., “Analysis of Forced Convection Enhancement in a Parallel Plate using Porous Blocks,” AIAA J. Thermophysics and Heat Transfer, Vol.18(1994), pp. 563-573.14.Hadim, H. A.and Bethancourt, A., “Numerical Study of Forced Convection in a Partially Porous Channel with Discrete Heat Sources,” J.Electronic package, Vol.117(1995), pp. 46-51.15.Kim S. Y. ,Kang B. H. and HYUN J. M. ,”Heat transfer from pulsating flow in channel filled with porous media,” Int. J. Heat Mass Transfer, Vol. 37. 2025-2033, 1994. 16.Kim S. Y. ,Kang B. H. , “Forced convection heat transfer from two heated blocks in pulsating channel flow,” Int. J. Heat Mass Transfer, Vol. 41, 625-634, 1998.17.Ghaddar, N. K., Magen, M., Mikic, B. B. and Patera, A. T., Numerical investigation of incompressible flow in grooved channels. Part 1. Stability and self-sustained oscillations. Journal of Fluid Mechanics, 1986, 163, 99-127.18.Ghaddar, N. K., Magen, M., Mikic, B. B. and Patera, A. T., Numerical investigation of incompressible flow in grooved channels. Part 2. Oscillatory heat transfer enhancement. Journal of Fluid Mechanics, 1986, 168, 541-567.19.Patanker, S. W., Numerical Heat Transfer and Fluid Flow , Chap.5-6, ,McGraw-Hill,New York(1980),pp. 79-138.20.Lundgren, T. S., “Slow Flow Through Stationary Random Beds and Suspensions of Spheres,” J.Fluid Mech, Vol.51(1972),pp. 273-299.21.Huang, P. C. and Vafai, K., “Analysis of Forced Convection Enhancement in a Parallel Plate using Porous Blocks,” AIAA J. Thermophysics and Heat Transfer, Vol.18(1994),pp. 563-573.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top