臺灣博碩士論文加值系統

本論文的內容可分為兩部分，是利用數值方法探討三維百葉窗型鰭管式熱交換器之熱流現象，主要針對不同的百葉窗角度(15°、20°、25°) 、不同百葉窗節距(Lp=0.75 mm、1 mm)、不同鰭片間距(6 fins/inch、8 fins/inch、12 fins/inch)與不同雷諾數ReH(以百葉窗節距當作參考，且正向速度1~5 m/s)進行數值運算，發現在相同的百葉窗節距與鰭片間距下，熱傳因子j與摩擦因子f隨百葉窗角度增加而增大。在相同鰭片間距與百葉窗角度下，熱傳因子j隨百葉窗節距減少而增加，摩擦因子f隨百葉窗節距減少而減少。在相同百葉窗節距與百葉窗角度下，熱傳因子j與摩擦因子f隨鰭片間距減少而增加。並配合實驗結果互相比較以驗證準確性。

Fluid flow and heat transfer over louver finned-tube heat exchangers under the dry condition were studied numerically and experimentally in the first year. The effects of different geometrical factor, including louver angle (15°,20°,25°), fin pitch (6, 8, 12 fins/inch), and louver pitch (1mm, 0.75mm) are investigated in detail for different Reynolds numbers. Numerical results indicate that both average Nusselt number and pressure drop coefficient are increased as louver angle is increased for the equal louver pitch；while for equal louver angle, they are increased as the fin pitch is decreased, and increased as the louver pitch is decreased. A comparison of the numerical results with the available experimental data was also presented.

摘要……………………………………………………………………Ⅰ
英文摘要………………………………………………………………Ⅱ
目錄……………………………………………………………………Ⅲ
圖目錄…………………………………………………………………Ⅴ
符號說明………………………………………………………………Ⅷ
第一章 序論…………………………………………………………1
第二章 理論分析……………………………………………………11
2-1 物理模型與基本假設………………………………………11
2-2 統御方程式與邊界條件……………………………………11
2-3 無因次化統御方程式與邊界條件…………………………13
2-4 熱傳係數與壓力係數之計算………………………………15
2-5 熱交換器性能評價方法……………………………………16
第三章 數值方法……………………………………………………22
3-1 方程式的建立………………………………………………22
3-2 格點產生……………………………………………………25
3-3 收斂條件……………………………………………………26
3-4 格點測試……………………………………………………26
第四章 結果與討論…………………………………………………30
4-1 正向風速的影響……………………………………………30
4-2 百葉窗角度的影響…………………………………………32
4-3 百葉窗節距的影響…………………………………………34
4-4 鰭片間距的影響……………………………………………35
第五章 結論…………………………………………………………63
參考文獻………………………………………………………………65

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