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研究生： 林谷韋
Lin gu-wei
論文名稱： 渦漩誘發振動之自然耦合現象的數值研究
Numerical analysis on natural coupling between fluid and structure due to vortex-induced vibration
指導教授： 白寶實
洪祖全
口試委員:
學位類別： 碩士
Master
系所名稱： 原子科學院 - 工程與系統科學系
Department of Engineering and System Science
論文出版年： 2002
畢業學年度： 90
語文別： 中文
論文頁數： 81
中文關鍵詞： 渦漩流動 、渦漩誘發振動 、PISO數值法 、Lock-in現象 、自然耦合流場
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    • 本論文主旨在於觀察低雷諾數下的層流（Laminar flow）流場中，結構體在承受流體的沖擊後，於結構體下游流域所形成的渦漩流動、流場變化，及渦漩與結構間的相互作用、運動型態等等，並探討渦漩誘發振動(Vortex-induced vibration)現象的發生，與結構形成破壞性的振盪現象。研究中運用計算流體力學的方式，求解此類問題；以PISO數值法將質量守恆方程式與Navier-Stokes動量方程式作一相互交替運算，並與結構體的運動方程式相結合，獲得流場中結構體的位移量，使流場系統中的結構因感受到流場變化的作用力影響而自然的產生運動；並於不同流場條件下，模擬流場變化與結構間可能的運動形態，觀察渦漩流動與結構體兩者之間頻率相對變化的關係，進一步的著手分析發生Lock-in現象時的流場變化與結構振動型態。在探討自然耦合流場的結構體運動與渦漩流動現象中，成功模擬出發生Lock-in現象時的圓柱體運動形式與渦漩流動;在自然耦合的流場，圓柱體會依循8字形軌跡運動，且其運動形式會與Lock-in現象的發生與否有相當的關聯性。另外，在二維的雙圓柱層流流場現象的探討方面，以並列(side-by-side) 與前後(tandem) 的圓柱體流場排列方式下，調整圓柱間相對距離變化，觀察對圓柱本身受力與渦漩結構的形成所造成的影響、渦漩流動型態轉變，及雙圓柱流場所存在的相互干擾現象。

    目錄 摘要 i 誌謝 ii 目錄 iii 圖目錄 vi 表目錄 x 符號系統 xi 1. 導論 1 2. 文獻回顧 2 3. 基本理論 6 3.1. 流場系統的簡介 6 3.2. 渦漩結構的形成 6 3.3. 單一圓柱流場 7 3.3.1. 不同雷諾數下的流場運動型態 7 3.3.2. 於垂直流動方向發生的Lock-in現象的流場變化 9 3.3.3. 在平行流動方向發生Lock-in現象的流場變化 10 3.4. 雙圓柱體流場 11 3.4.1. 圓柱體振動所形成的流場模型及其影響 11 3.4.2. 以並列方式排列的雙圓柱流場現象 13 3.4.3. 以前後方式排列的雙圓柱流場現象 14 3.5. 研究中所使用的無因次參數和相關係數的定義 16 3.5.1. Strouhal number的定義 16 3.5.2. Reynolds number的定義 16 3.5.3. Drag coefficient的定義 17 3.5.4. 升力係數（Lift coefficient）的定義 17 4. 模擬理論與方法 19 4.1. 結構體運動方程式 19 4.2. 論文中使用的數值方法介紹 21 4.2.1. PISO方法 21 4.2.2. ADI（Alternating-direction implicit method）方法的基本 概念……………. 22 4.3. CFD軟體的流場設定……………………………………………….22 4.3.1. 流場的初始狀態設定（Field Initialization） 22 4.3.2. 時間步階（Time step）的設定 23 4.3.3. 系統幾何座標的選擇與模型的建立 23 4.3.4. 流場系統的網格分布設定 24 4.3.5. 流場的狀態設定 24 4.3.6. 流場進口與出口條件的設定 25 4.3.7. 移動網格（Moving Grid）設定 26 4.4. 流場系統的Domain測試 27 4.5. 流場系統的網格測試 31 5. 分析與討論 34 5.1. 單一圓柱流場分析，探討流場壓力差所造成的流場現象 34 5.1.1. 改變流場進口流速設定，探討流場的變化與影響 34 5.1.2. 改變阻尼係數ξ值 ，觀察其對於流場運動所造成的影響 .………… 40 5.1.3. 同比例改變 m、k值，視其對流場的影響(阻尼係數ξ值固定為0.3) 42 5.1.4. 改變結構體自然振動頻率fn，視不同頻率比值(結構體自 然振動頻率fn 與渦漩頻率 fv) 對流場的影響 44 5.1.5. 模擬雷諾數400時的Lock-in現象 48 5.2. 流場壓力與剪應力對單一圓柱流場現象的影響 50 5.2.1. 探討剪應力對於不同雷諾數的圓柱流場現象的影響 50 5.2.2. 改變結構體自然振動頻率fn，視不同頻率比值 ( 結構體 自然振動頻率 fn 與渦漩頻率 fv) 對流場的影響 53 5.3. 兩根圓柱體流場模擬 56 5.3.1. 雙圓柱並列流場探討 56 5.3.2. 雙圓柱前後排列的流場探討 64 6. 結論與未來工作 75 參 考 文 獻 77

    參 考 文 獻
    1. Bishop, R.E.D., and Hassan, A.Y., “The lift and Drag Forces on a Circular Cylinder in a Flowing Field“, Proc. Roy. Soc.(London), Ser.A, 277, pp. 51-75, 1964.
    2. Koopman, G.H., “The Vortex Wakes of Vibrating Cylinders at Low Reynolds Numbers”, J. Fluid Mech., Vol. 27, pp. 501-512, 1967.
    3. Feng, C. C., “The Measurement of Vortex-Induced Effects in Flow Past Stationary and Oscillating Circulator and D-Section Cylinder”, M. Sc. Thesis, University of British Colimbia, 1968.
    4. Griffin. O.M., “The Unsteady Wake of an Oscillating Cylinder at Low Reynolds Number”, J. Applied Mech., Vol. 38, pp. 729-738, 1971.
    5. Griffin, O.M., and Ramberg, S.E., “Some Recent Studies of Vortex Shedding with Application to Marine Tubulars and Riser”, ASME Journal of Energy Research and Technology, Vol.104, pp. 2-13, 1982.
    6. Ongoren, A., and Rockwell, D., “Flow Structure From an Oscillating Cylinder. Part 1:Mechanisms of Phase Shift and Recovery in the Near Wake”, J. Fluid Mech., Vol. 191, pp. 197-223, 1988a.
    7. Williamson, C.H.K., and Roshko, A., “Vortex Formation in the Wake of an Oscillating Cylinder”, J. Fluids and Structures, Vol. 2, pp. 355-381, 1988.
    8. Parkinson, G., “Phenomena and Modeling of Flow-Induced Vibrations of Bluff Bodies”, Progress in Aerospace Sciences, Vol. 26, pp. 169-224, 1989.
    9. Hurlbut, M., Spaulding, M.L. and White, F.M., “Numerical Solution for Laminar Two Dimensional Flow about a Cylinder Oscillating in a Uniform Stream”, ASME Journal of Fluids Engineering, Vol. 104, pp. 214-222, 1982.
    10. Mittlal, S., and Tezduyar, T.E., “A Finite Element Study of Incompressible Flows Past Oscillating Cylinders and Airfoils”, Int. J. for Numerical Methods in Fluids, Vol. 15, pp. 1073-1118, 1992.
    11. Blackburn, H., and Henderson, R., “Lock-in Behavior in Simulated Vortex-Induced Vibration”, Experimental Thermal and Fluid Science, Vol. 12, No. 2, pp. 184-189, Feb. 1996.
    12. Varaprasad Patnaik, B.S., Aswatha Narayana, P.A., Seetharamu, K.N., “Numerical Simulation of Vortex Shedding Past a Circular Cylinder under the Influence of Buoyancy”, Int. J. Heat and Mass Transfer, Vol. 42, pp. 3495-3507, 1999.
    13. Ramaprian, B.R., and Zheng Y., “Near Field of the Tip Vortex Behind an Oscillating Rectangular Wing”, AIIA Journal, Vol.36, No.7, pp.1263-1269, 1998.
    14. Chung, Jin.S., Whitney, A.K., and Lezius, D., “Flow-Induced Torsional Moment and Vortex Suppression for a Circular Cylinder with Cables”, Proceedings of the International Offshore and Polar Engineering Conference, Vol. 3, pp. 447-467, 1994.
    15. Sakamoto, H., and Haniu, H., “Optimum Suppression of Fluid Forces Acting on a Circular Cylinder”, ASME Journal of Fluids Engineering, Vol. 116, No. 2, pp. 221-222, 1994.
    16. Hiejima, S., Nomura, T., Kimura, K., and Fujino, Y., “Numerical Study on the Suppression of the Vortex-Induced Vibration of a Circular Cylinder by Acoustic Excitation”, J. Wind Engineering and Industrial Aerodynamics,Vol.67, pp. 325-335,1997.
    17. Abbassian, F., and Moros, T., “Use of Air-Bubble Spoilers to Suppress Vortex-Induced Vibrations of Risers”, SPE Production & Facilities, Vol. 11, No. 1, pp. 35-47, 1996.
    18. Zdravkovich, M.M., “Review of Flow Interference between Two Circular Cylinders in Various Arrangements,” J. Fluids Eng., Vol. 99, pp. 618-633, 1977.
    19. King, R., and Johns, D.J., “Wake Interaction Experiments with Two Flexible Circular Cylinders in Flowing Water,” J. Sound Vib., Vol. 45, No. 2, pp. 259-283, 1976.
    20. Jendrzejczyk, J.A., and Chen, S.S., and Wambsganss, M.W. “Dynamic Response of a Pair of Circular Tubes Subjected to Liquid Cross Flow,” J. Sound Vib., Vol. 67, No. 2, pp. 263-273, 1979.
    21. Blenvins, Robert D., “Flow-Induce Vibration”, Robert E. Krieger publishing company, 1986.
    22. Griffin, O.M., and Ramberg, S.E., “The Effects of Synchronized Cylinder Vibrations on Vortex Formation and Strength, Velocity Fluctuations, and Mean Flow”, Paper E-3, Presented at the Symposium on Flow Induced Structural Vibrations, Held in Karlsruhe, Germany, 14-16, August, 1972.
    23. Lienhard, J.H., “Synopsis of Lift, Drag and Vortex Frequency Data for Rigid Circular Cylinders”, Washington State University College of Engineering, Research Division Bulletin, 300, 1966.
    24. Roshko, A., ”Experiments on the Flow Past a Cylinder at Vary High Reynolds Number”, J. Fluid Mech., 10, pp. 345-356, 1961.
    25. Griffin, O. M., and Hall M. S., “Review-Vortex Shedding Lock-on and Flow Control in Bluff Body Wakes”, ASME Journal of Fluids Engineering, Vol. 113, pp. 527-537, 1991.
    26. Griffin, O.M., and Ramberg, S.E., “Vortex Shedding From a Cylinder Vibrating in Line With an Incident Uniform Flow”, J. Fluid Mech., Vol. 75, pp. 257-271, 1976.
    27. Tanida, Y., Okajima, A., and Watanabe, Y., “Stability of a Circular Cylinder Oscillating in Uniform Flow or in a Wake”, J. Fluid Mech., Vol. 61, Part 4, pp. 769-784, 1973.
    28. Tatsuno, M., “Vortex Streets Behind a Circular Cylinder Oscillating in the Direction of Flow”, Bull. Res. Inst. Appl. Mech., Kyushu University, Vol. 36, pp. 25-37, 1972.
    29. Zdravkovich, M. M., “Flow Induced Oscillations of Two Interfering Circular Cylinders.”, Int. Conf. on Flow Induced Vibrations in Fluid Engineering, Reading, England, Sept. 14-16, 1982, Paper No. D2.,1982.
    30. Zdravkovich, M. M., “Classification of Flow-Induced Oscillations of Two Parallel Circular Cylinders in Various Arrangement.”, ASME In Sym. On Flow-Induced Vibration, Vol. 2, ppl1-18,1984.
    31. Achenbach,E., “Distribution of Local Pressure and Skin Friction around a Circular Cylinder in Cross-Flow up to Re=5 106 ”, J. Fluid Mech.,Vo. 34,No. 3,pp.625-639, 1968.
    32. King, R., “A Review of Vortex Shedding Research and Its Application”, Ocean Engineering, Vol. 4, pp.141-171, 1977a.
    33. Stansby, P.K. and Slaouti, A., “Simulation of Vortex Shedding Including Blockage by the Random-Vortex and Other Methods,” Int. J. Numerical Methods in Fluids, Vol. 17,pp. 1003-1013,1993.
    34. Williamson, C. H. K., “Oblique and Parallel Models of Vortex Shedding in the Wake of a Circular Cylinder at Low Reynolds Numbers,” J. Fluid Mechanics, Vol. 206, pp.579-627, 1989.
    35. Zhou C.Y., So R. M. C. and Lam K., “Vortex-Induced Vibration of an Elastic Circular Cylinder,” J. Fluids and Structures, Vol. 13,pp.165-189, 1999.

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