臺灣博碩士論文加值系統

針對目前高效率電子設備為了發展散熱技術，常會使用密集式熱交換器，在密集式熱交換器等此類的相關相關元件中，因應逐漸微小化的電子設備本體，會於有限的空間內前後對應的長方形流道通常用一個突擴、突縮段來做連接，然而目前只有一些單相流壓力變化和熱傳的論文發表過，關於微小流道的壓力驟變相關的研究卻很少被提出討論，甚至於兩相流體流過突擴、突縮段的研究都沒有發現，因此本研究的目的就是要探討在此突擴段內的兩相流摩擦壓力變化關係和流型與其相對的變化。
此實驗將用透明的壓克力板做成帶有突擴段的長方形流道以方便觀察兩相流流型的型態，這些測試段將具有類似的幾何型狀和結構，其流道的窄度皆為3㎜，而寬度分別是6、9㎜（ ＝4、4.5㎜）以顯現其突擴段表現的特徵性，測試的空氣和水之質通率從100到 700 kg/m2.s和乾度則從0.001到 0.1，在一般國內常溫下的實驗參數下測試。
進而根據這長方形流道所參照公認理論的空泡比值加以比較，配合流型和摩擦壓力變化的數據將用來互相比對現有模式預測的正確度，解釋與其相關實驗的性別差異所在，另外在突擴段所量得的兩相流摩擦壓力變化數據將用來整理成一個實用的數學經驗式用來預測通過突擴段的摩擦壓力變化，且通過這突擴段兩相流流型的結構和變化，解釋在接頭內壓力變化變化的原因。

針對目前高效率電子設備為了發展散熱技術，常會使用密集式熱交換器，在密集式熱交換器等此類的相關相關元件中，因應逐漸微小化的電子設備本體，會於有限的空間內前後對應的長方形流道通常用一個突擴、突縮段來做連接，然而目前只有一些單相流壓力變化和熱傳的論文發表過，關於微小流道的壓力驟變相關的研究卻很少被提出討論，甚至於兩相流體流過突擴、突縮段的研究都沒有發現，因此本研究的目的就是要探討在此突擴段內的兩相流摩擦壓力變化關係和流型與其相對的變化。
此實驗將用透明的壓克力板做成帶有突擴段的長方形流道以方便觀察兩相流流型的型態，這些測試段將具有類似的幾何型狀和結構，其流道的窄度皆為3㎜，而寬度分別是6、9㎜（ ＝4、4.5㎜）以顯現其突擴段表現的特徵性，測試的空氣和水之質通率從100到 700 kg/m2.s和乾度則從0.001到 0.1，在一般國內常溫下的實驗參數下測試。
進而根據這長方形流道所參照公認理論的空泡比值加以比較，配合流型和摩擦壓力變化的數據將用來互相比對現有模式預測的正確度，解釋與其相關實驗的性別差異所在，另外在突擴段所量得的兩相流摩擦壓力變化數據將用來整理成一個實用的數學經驗式用來預測通過突擴段的摩擦壓力變化，且通過這突擴段兩相流流型的結構和變化，解釋在接頭內壓力變化變化的原因。

目 錄

中文摘要 …………………………………………………… i
英文摘要 …………………………………………………… ii
誌謝 …………………………………………………… iv
目錄 …………………………………………………… v
表目錄 …………………………………………………… vii
圖目錄 …………………………………………………… viii
符號說明 …………………………………………………… xii
第一章 緒論……………………………………………… 1
1.1 研究背景與動機………………………………… 1
1.2 研究目的………………………………………… 3
第二章 文獻回顧………………………………………… 4
2.1 直管兩相流摩擦壓力變化……………………… 5
2.1.1 基礎理論模式…………………………………… 5
2.1.2 經驗式…………………………………………… 7
2.2 流經突擴段及突縮段的壓損…………………… 10
2.3 兩相流突擴壓力變化…………………………… 11
2.4 流譜……………………………………………… 16
2.4.1 流譜型態種類…………………………………… 16
2.4.2 流譜預測方法…………………………………… 20
第三章 實驗系統與分析方法…………………………… 26
3.1 簡介……………………………………………… 26
3.2 水-空氣實驗系統………………………………… 26
3.2.1 測試段…………………………………………… 26
3.2.2 照相段…………………………………………… 27
3.2.3 空氣循環系統…………………………………… 27
3.2.4 水循環系統……………………………………… 27
3.2.5 液氣混合區……………………………………… 28
3.3 實驗儀器………………………………………… 28
3.3.1 資料擷取系統（紀錄器）………………………… 28
3.3.2 溫度量測………………………………………… 29
3.3.3 壓力量…………………………………………… 29
3.3.4 壓力差量測……………………………………… 30
3.3.5 水流量量測.……………………………………… 31
3.3.6 空氣流量量測…………………………………… 31
3.3.7 照明設備………………………………………… 33
3.4 工作流體的熱力物理性質……………………… 33
3.5 實驗過程………………………………………… 34
3.5.1 系統測漏………………………………………… 34
3.5.2 實驗操作步驟…………………………………… 34
3.6 實驗觀察………………………………………… 35
3.6.1 流譜型態分析…………………………………… 35
3.6.2 水-空氣流譜實驗數據換算……………………… 35
第四章 結果與討論……………………………………… 34
4.1 兩相流突擴段壓力變化與空泡比之關係……… 40
4.2 兩相流突擴段壓力變化情形…………………… 40
4.3 兩相流突擴段壓力變化與流譜關係…………… 42
第五章 結論……………………………………………… 67
參考文獻 …………………………………………………… 68

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