臺灣博碩士論文加值系統

本文以逆向方法及實驗特定溫度點的量測搭配ANSYS ICEPAK 15中各種流動模式的比較，確立合適於散熱水平鰭片置於封閉空腔內的熱壁中之系統的流動模式，再經由合適的流動模式預測水平鰭片之熱傳導係數及觀測鰭片對於封閉空腔內的流場產生之影響。實驗方面以穿孔及未穿孔鰭片隨鰭片位置、鰭片間距及鰭片數量等測試對鰭片表面的熱傳導係數及鰭片本身周圍的流場產生之影響。並利用ANSYS ICEPAK 15進行網格測試，研究網格劃分對於系統求解的影響。結果顯示雙鰭片在熱傳導係數的表現上複雜許多，鰭片間邊界層的互相影響或鰭片與空腔上下邊界的互相影響，使得鰭片之熱傳係數不再只是隨著鰭片間距增加而上升，透過以實驗數據搭配數值結果的溫度分布圖及速度流線圖去分析實驗的實驗數據的種種現象，另外嘗試以無因次參數進行流場行為之說明，並和研究結果進行互相驗證，最後為了驗證結果之可靠性及可用性，將所求結果與相關參考文獻之現象比較，得到穿孔鰭片確實能破壞鰭片周圍之邊界層，促使鰭片附近的流場趨於紊亂，流場之流速提升，鰭片本身的熱傳導係數也有所提升。

The present study applies the inverse method and computational fluid dynamics (CFD) software along with experimental method to predict the heat transfer and fluid characteristics of fins on a hot wall in a cavity. The effects of some physical parameters such as fin spacing, fin diameter and fin numbers, are examined. The inverse method applied finite difference method in conjunction with the least-squares scheme and the experimental data to estimate the heat transfer coefficient on the fins. With the methods of Rayleigh number with references and the comparsion between experimental and numerical results to obtain the appropriate flow model are included. Effect of perforation on fins in a cavity around fin is investigated by the temperature contour, velocity field and heat transfer characteristic. Perforation cause perturbation and reinforce heat convection around fins. Increase of Heat transfer coefficient and the change of temperature distribution on fins can be observed under the influence of perforation. Perforation cannot cause additional effect on fins. We found that the incease of heat transfer coefficient by the effect of perforation didn’t change under different parameters, such as fin postion, fin spacing and fin numbers under investigation. Although the effect of perforation can increase heat transfer coefficient on fins, the use of perforation on fins exists many challenges.

目錄
摘要 I
Extended Abstract II
目錄 VIII
表目錄 XI
圖目錄 XIII
符號說明 XVI
第 1 章 緒論 1
1-1 研究背景 1
1-2 文獻回顧 3
1-3 研究方法與目的 7
1-4 研究重點與本文架構 9
第 2 章 逆算法之理論與建構過程 11
2-1 簡介 11
2-1 建立數學模型 12
2-3 鰭片之逆向方法 13
第 3 章 實驗方法 21
3-1 簡介 21
3-2 實驗設備 24
3-3 實驗組別 28
3-4 實驗步驟 28
第 4 章 三維CFD軟體模擬 31
4-1 簡介 31
4-2 基本假設 32
4-3 流動模式之統御方程組 33
4-3-1 層流模式(Laminar model) 34
4-3-2 Zero-equation紊流模式 34
4-3-3 Standard k-ε紊流模式（k-ε turbulence model） 35
4-3-4 RNG k-ε紊流模式 38
4-4 邊界條件 39
4-5 數值求解分析 41
4-5-1 流動模式之選定 41
4-5-2 網格劃分 44
第 5 章 結果與討論 57
5-1 簡介 57
5-2 穿孔鰭片與未穿孔鰭片之結果比較 58
5-2-1 實驗與逆向結果分析 59
5-2-2 數值結果分析 61
5-3 鰭片位置對所求結果之影響 63
5-3-1 實驗與逆向結果分析 64
5-3-2 數值結果分析 65
5-4 鰭片間距對所求結果之影響 66
5-4-1 實驗與逆向結果分析 67
5-4-2 數值結果分析 70
5-5 鰭片的熱傳導係數h̅極值比較與分析 73
5-6 鰭片對系統空腔與外界換熱之影響 75
第 6 章 結論與建議 118
6-1 綜合結論 118
6-2 建議與未來發展 120
參考文獻 123


 
表目錄
表3 1鰭片之物理量 26
表4 1對應L = 0.03 m、Hfp = 0.06m、d = 0.025m、Dl =0.005m之標準鰭片不同流動模式對所求結果的影響 47
表4 2對應L = 0.03 m、Hfp = 0.085m、d = 0.025m、Du=0.005m之上鰭片不同流動模式對所求結果的影響 47
表4 3對應L = 0.03 m、Hfp = 0.06m、d = 0.025m、Dl =0.005m之外部流場網格變化對所求結果的影響 48
表4 4對應L = 0.03 m、Hfp = 0.085m、d = 0.025m、Du=0.005m之外部流場網格變化對所求結果的影響 48
表4 5對應L = 0.03 m、Hfp = 0.06m、d = 0.025m、Dl =0.005m之鰭片上z方向網格變化對所求結果的影響 49
表4 6對應L = 0.03 m、Hfp = 0.085m、d = 0.025m、Du=0.005m之鰭片上z方向網格變化對所求結果的影響 49
表5 1 對應單一鰭片各種 Hfp之量測值與數值分析值 77
表5 2 對應穿孔單一鰭片各種 Hfp之量測值與數值分析值 77
表5 3 對應Hfp=0.06m與各種d值上鰭片之量測值與數值分析值 78
表5 4 對應Hfp=0.06m與上鰭片各種d值之標準鰭片之量測值與數值分析值 78
表5 5 對應Hfp=0.06m與各種d值之下鰭片之量測值與數值分析值 79
表5 6 對應Hfp=0.06m與下鰭片各種d值之標準鰭片之量測值與數值分析值 79
表5 7 對應Hfp=0.06m與各種d值之穿孔上鰭片之量測值與數值分析值 80
表5 8 對應Hfp=0.06m與穿孔上鰭片各種d值之穿孔標準鰭片之量測值與數值分析值 80
表5 9 對應Hfp=0.06m與各種d值之穿孔下鰭片之量測值與數值分析值 81
表5 10 對應Hfp=0.06m與穿孔下鰭片各種d值之穿孔標準鰭片之量測值與數值分析值 81
表5 11 對應Hfp=0.085m與各種d值之下鰭片之量測值與數值分析值 82
表5 12 對應Hfp=0.085m與下鰭片各種d值之標準鰭片之量測值與數值分析值 82
表5 13 對應Hfp=0.085m與各種d值之穿孔下鰭片之量測值與數值分析值 83
表5 14 對應Hfp=0.085m與穿孔下鰭片各種d值之穿孔標準鰭片之量測值與數值分析值 83
表5 15 對應Hfp=0.035m與各種d值之上鰭片之量測值與數值分析值 84
表5 16 對應Hfp=0.035m與上鰭片各種d值之標準鰭片之量測值與數值分析值 84
表5 17 對應Hfp=0.035m與各種d值之穿孔上鰭片之量測值與數值分析值 85
表5 18 對應Hfp=0.035m與穿孔上鰭片各種d值之穿孔標準鰭片之量測值與數值分析值 85
表5 19 對應以Hfp=0.06m為中心對稱各種d值上鰭片之量測值與數值分析值 86
表5 20 對應以Hfp=0.06m為中心對稱各種d值下鰭片之量測值與數值分析值 86
表5 21 對應以Hfp=0.06m為中心對稱各種d值穿孔上鰭片之量測值與數值分析值 87
表5 22 對應以Hfp=0.06m為中心對稱各種d值穿孔下鰭片之量測值與數值分析值 87
表5 23 對應各種情況之鰭片之h̅max比較 88
表5 24 對應各種情況之鰭片之h̅min比較 88
 
圖目錄
圖1 1 研究方法流程圖 8
圖2 1矩形鰭片之格點示意圖 18
圖2 2內部格點差分運算示意圖 19
圖2 3穿孔矩形鰭片之子區域及量測點示意圖 20
圖3 1實驗系統示意圖 22
圖3 2實驗幾何模型示意圖(a)xz平面(b)yz平面 23
圖3 3實驗用熱源裝置 27
圖3 4溫度擷取設備產品實體圖 27
圖4 1 ICEPAK軟體兼FLUENT分析之流程與架構 50
圖4 2 SIMPLE演算法之流程 51
圖4 3熱流模擬軟體ANSYS Icepak 15.0操作流程 52
圖4 4計算區域示意圖 53
圖4 5非結構化網格示意圖 53
圖4 6對應L= 0.03m、W= 0.1m及d= 0.025m之網格示意圖(a)xz平面(b)等角視圖 54
圖4 7對應Hfp=0.06m之穿孔標準鰭片及d=0.025m之穿孔上鰭片於y-z平面上x=L/2處之溫度分布圖 (a)零方程式模式 (b)層流模式 55
圖4 8對應Hfp=0.06m之穿孔標準鰭片及d=0.025m之穿孔上鰭片於x-z平面上y=W/2處之溫度分布圖 (a)零方程式模式 (b)層流模式 56
圖5 1對應Hfp=0.035m於x-z平面上y=W/2處之速度流線圖 89
圖5 2 對應Hfp=0.035m於y-z平面上x=L/2處之速度流線圖 90
圖5 3 對應Hfp=0.06m於y-z平面上x=L/2處之速度流線圖 91
圖5 4 對應Hfp=0.085m於y-z平面上x=L/2處之速度流線圖 92
圖5 5 對應Hfp=0.06m之標準鰭片及d=0.025m之下鰭片於y-z平面上x=L/2處之速度流線圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 93
圖5 6 對應Hfp=0.06m之標準鰭片及d=0.025m之上鰭片於y-z平面上x=L/2處之速度流線圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 94
圖5 7 對應以Hfp=0.06m為中心對稱d=0.025m於y-z平面上x=L/2處之速度流線圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 95
圖5 8 對應以Hfp=0.06m為中心對稱d=0.025m於x-z平面上y=W/2處之速度流線圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 96
圖5 9 對應以Hfp=0.06m為中心對稱d=0.025m於x-z平面上y=W/2處之溫度分布圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 97
圖5 10 對應以Hfp=0.06m為中心對稱d=0.015m於x-z平面上y=W/2處之速度流線圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 98
圖5 11 對應以Hfp=0.06m為中心對稱d=0.015m於x-z平面上y=W/2處之溫度分布圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 99
圖5 12 對應以Hfp=0.06m為中心對稱d=0.005m於x-z平面上y=W/2處之速度流線圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 100
圖5 13 對應以Hfp=0.06m為中心對稱d=0.005m於x-z平面上y=W/2處之溫度分布圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 101
圖5 14 對應Hfp=0.085m之標準鰭片及d=0.005m之下鰭片於x-z平面上y=W/2處之溫度分布圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 102
圖5 15 對應Hfp=0.085m之標準鰭片及d=0.01m之下鰭片於x-z平面上y=W/2處之溫度分布圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 103
圖5 16 對應Hfp=0.035m之標準鰭片及d=0.005m之下鰭片於x-z平面上y=W/2處之溫度分布圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 104
圖5 17 對應Hfp=0.035m之標準鰭片及d=0.01m之下鰭片於x-z平面上y=W/2處之溫度分布圖 (a)無穿孔鰭片組 (b)穿孔鰭片組 105
圖5 18 對應Hfp=0.035m之標準鰭片及各種d值上鰭片於x-z平面上y=W/2之速度流線圖 (a) d=0.005m (b) d=0.01m 106
圖5 19 對應Hfp=0.035m之標準鰭片及各種d值上鰭片於x-z平面上y=W/2之速度流線圖 (a) d=0.025m (b) d=0.045m 107
圖5 20 對應Hfp=0.06m之標準鰭片及各種d值上鰭片於x-z平面上y=W/2之速度流線圖 (a) d=0.005m (b) d=0.01m 108
圖5 21 對應Hfp=0.06m之標準鰭片及各種d值上鰭片於x-z平面上y=W/2之速度流線圖 (a) d=0.015m (b) d=0.025m 109
圖5 22 對應Hfp=0.085m之標準鰭片及各種d值下鰭片於x-z平面上y=W/2之速度流線圖 (a) d=0.005m (b) d=0.045m 110
圖5 23 對應Hfp=0.06m標準鰭片及各種d值之上鰭片的溫度分布圖 (a) d=0.005m (b) d=0.01m 111
圖5 24 對應Hfp=0.035m標準鰭片及各種d值之上鰭片的溫度分布圖 (a) d=0.005m (b) d=0.01m 112
圖5 25 對應單一鰭片隨各種 Hfp之h̅的比較 113
圖5 26 對應Hfp=0.06m標準鰭片隨非標準上鰭片各種d值之h̅變化 113
圖5 27 對應Hfp=0.06m標準鰭片隨非標準下鰭片各種d值之h̅變化 114
圖5 28對應Hfp=0.085m標準鰭片隨非標準鰭片各種d值之h̅變化 114
圖5 29 對應Hfp=0.035m標準鰭片隨非標準鰭片各種d值之h̅變化 115
圖5 30 對應以Hfp=0.06m為中心上下鰭片對中心各種d值之h̅變化 115
圖5 31 對應以Hfp=0.06m標準鰭片隨上下鰭片各種d值之h̅變化 116
圖5 32 對應鰭片h̅max與h̅min隨鰭片數目的h̅變化 116
圖5 33 對應不同高度鰭片隨鰭片間距之h̅變化 117

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