研究生: |
張元榕 |
---|---|
論文名稱: |
微氣泡於小口徑垂直方管內浮升之研究 On the Rising of a Tiny Bubble in a Small Vertical Square Tube |
指導教授: | 李雄略 |
口試委員: | |
學位類別: |
碩士 Master |
系所名稱: |
工學院 - 動力機械工程學系 Department of Power Mechanical Engineering |
論文出版年: | 2005 |
畢業學年度: | 93 |
語文別: | 中文 |
論文頁數: | 48 |
中文關鍵詞: | 氣泡 、表面張力 、浮升 、兩相流 |
相關次數: | 點閱:1 下載:0 |
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本文提出了一簡單的數值方法解決微小氣泡在自由液面兩側存在巨大壓力落差的問題,成功的把壓力落差資訊在氣體與液體區做交換,使得控制質量守恆的壓力連結方程式可以跨相處理,而簡化許多模擬步驟的繁雜手續。而且此數值方法,在粗網格時,仍有相當準確的表現,此法的模擬結果與實驗結果做歸納比對,有相當的參考性與準確性。
並在研究中發現表面張力透過曲率變化影響自由液面上的壓力落差,進而利用壓力梯度影響流場。並且發現曲率變化對流場的影響非常劇烈,一個看起來幾乎沒有變形的氣泡,若以沒有變形來模擬會產生很大的誤差。而只要有輕微變形(r=1.0003),流場就會產生很敏感的變化。本文最後推論舊有的兩相流數值模擬手法中,以上個時間所推得的自由液面遷移速度,推測下個時間的自由液面形狀及曲率,在微小尺度容易產生相當巨大的數值誤差與雜訊,將無法適用於微小尺度的模擬。
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