簡易檢索 / 詳目顯示

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
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報
  • 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。


    摘要 I 誌謝 II 目錄 III 圖目錄 V 符號說明 VI 第一章 緒論 1 1.1前言 1 1.2文獻回顧 2 1.3本文目的 6 第二章 理論分析 7 2.1問題描述 7 2.2建立統御方程式 8 2.2統御方程式的無因次化 10 2.3 導入曲率變化 12 2.4邊界條件 14 第三章 數值方法 16 3.1動量方程式之差分 17 3.2壓力連結方程式-利用NAPPLE求解 20 3.4計算流程 24 第四章 結果與討論 25 4.1模擬參數 25 4.2流場與壓力場 26 4.3 網格的影響測試 30 4.4 終端速度與氣泡大小關係 30 第五章 結論 32 參考文獻 33

    [1] Saffman, P.G., 1956, “On the rise of small air bubbles in water,” J. Fluid Mech., 3, pp. 249-275.
    [2] Legendre, D., Maganaudet, J., 1998, “The lift force on a spherical bubble in a viscous linear shear flow,” J. Fluid Mech., 368, pp. 81-126.
    [3] Krishna, R., Urseanu, M.I., van Baten, J.M., Ellenberger, 1999, “Wall effects on the rise of single gas bubbles in liquids,” Int. Comm. Heat Mass Transfer, 26, pp. 781-790.
    [4] Ortiz-Villafuerte, J., Hassan, Y.A., Schmidl, W. D., 2001, “Rocking motion, trajectory and shape of bubbles rising in small diameter pipes,”Experimental Thermal and Fluid Science, 25, pp. 43-53.
    [5] Wu, M., Gharib, M., 2002, “Experimental studies on the shape and path of small air bubbles rising in clean water,” Physics of Fluids, 14, pp. L49-L52.
    [6] Takemura, F., Takagi, S., Magnaudet, J., et al., 2002, “Drag and lift forces on a bubble rising near a vertical wall in a viscous liquid,” J. Fluid Mech., 461, pp. 277-300.
    [7] Lee, S. L., and Sheu, S.R., 2001, “A new numerical formulation for incompressible viscous free surface flow without smearing the free surface,”International Journal of Heat and Mass Transfer, 44, pp. 1831-1848.
    [8] Sarpkaya, T., 1996, “Vorticity, free surface and surfactants,” Annual Review of Fluid Mechanics, 28, pp. 83-128.
    [9] Tsai, W. T., and Yue, D. K. P., 1996, “Computation of nonlinear free-surface flows,”Annual Review of Fluid Mechanics, 28, pp. 249-278.
    [10] Lee, S. L., 1989, “Weighting function scheme and its application on multidimensional conservation,” International Journal of Heat and Mass Transfer, 32, pp. 2065-2073.
    [11] Lee, S. L., and Tzong, R. Y., 1991, “An enthalpy formulation for phase change problems with a large thermal diffusivity jump across the interface,” International Journal of Heat and Mass Transfer, 34, pp. 1491-1502.
    [12] Lee, S. L., and Tzong, R. Y., 1992, “Artificial pressure for pressure-linked equation,” International Journal of Heat and Mass Transfer, 35, pp. 2705-2716.
    [13] Lee, S. L., 1989, “A strongly-implicit solver for two-dimensional elliptic differential equations,” Numerical Heat Transfer, Vol.16, pp. 161-178.
    [14] Hirt, C. W., and Nichols, B. D., 1981, “Volume of Fluid (VOF) method for the dynamics of free boundaries,” J. Computational Physics, 39, pp.201.
    [15] Unverdi, S., and Tryggvason, G., 1992, “A front-tracking method for viscous incompressible, mutifluid flows,” J. Computational Physics, 100, pp. 25-37.
    [16] Shin, S., and Juric, F., 2002, “Modeling three-dimensional multiphase flow using a level contour reconstruction method for Front Tracking without Connectivity,” J. Computational Physics, 180, pp. 427-470.
    [17] Lee, S. L. and Lee, H. D., 2003, “Evolution of the liquid meniscus in a capillary-force-dominant flow,” The 14th International Symposium on Transport Phenomena.
    [18] Lee, S. L. and Liao, W. C., 2005, “Numerical simulation of a fountain flow on nonstaggered Cartesian grid system,” 2005 ASME Fluid Engineering Division Summer Meeting and Exhibition.
    [19] White, Frank M.,1991, “Viscous Fluid Flow”, 2nd ed., McGraw-Hill, New York.,pp183-184.

    無法下載圖示 全文公開日期 本全文未授權公開 (校內網路)
    全文公開日期 本全文未授權公開 (校外網路)

    QR CODE