研究生: |
高豫立 Yu-li Kao |
---|---|
論文名稱: |
在壹個具有旋轉或無旋轉控制圓桿影響下圓柱周圍的流場特性討論 Flow characteristics around a cylinder under the influence of another smaller cylinder with and without rotation |
指導教授: |
洪俊卿
Jin-Tsing Hong |
口試委員: |
孫珍理
Chen-li Sun 蔡尤溪 Yew Khoy Chuah |
學位類別: |
碩士 Master |
系所名稱: |
工程學院 - 機械工程系 Department of Mechanical Engineering |
論文出版年: | 2007 |
畢業學年度: | 95 |
語文別: | 中文 |
論文頁數: | 96 |
中文關鍵詞: | 圓柱 、控制圓桿 、渦旋逸放 、卡門渦街 、壓力梯度 、分離點 |
外文關鍵詞: | 無 |
相關次數: | 點閱:384 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 |
本研究以數值模擬的方法來探討在二維流場中,流體流經單圓柱,及流體流經在圓柱附近放置無旋轉及旋轉控制圓桿之圓柱周圍的流場特性。
當無控制圓桿的作用時,在雷諾數大於60時,圓柱周圍的流場會有因渦旋逸放形成卡門渦街(Karman vortex street)的結構,圓柱之CD、CL曲線呈週期性震盪型態。
先在圓柱附近放置無旋轉控制圓桿,則其周圍流場及對應的壓力分佈,會隨控制圓桿置放位置不同而有不同的變化,使其(St, CD, CL, θs)值都產生變化。研究發現由於控制圓桿的存在,常使圓柱表面產生兩個正向壓力梯度的區域,從而使分離點往後移至第二個正向壓力梯度範圍的地方。
本研究發現利用旋轉控制圓桿可以抑制渦旋逸放,其抑制效果,隨控制圓桿轉速增加,或流場雷諾數降低而增強。在旋轉控制圓桿作用下,圓柱CD值有可能增加,有可能減小,甚至變成負值。
無
[1] Strouhal, V., Uber enie Besondere Art der Tonerregung, Annalen der Physik und Chemie(Leipzig), pp. 217-251, 1878.
[2] Morkovin, M. V., "Flow Around a Circular Cylinder - A Kaleidoscope of Challenging Fluid Phenomena," ASME Symposium on Fully Separated Flows, pp. 102—118, 1964.
[3] Lienhard, J. H., Synopsis of Lift, Drag and Vortex Frequency Data for Rigid Circular Cylinders, Research Division Bulletion 300, Washington State University, 1966.
[4] Prandtl, L., Uber Flussigkeitsbewegung bei sehr kleiner Reibung, Proc. Third Int. Math. Congr., Heidelberg, Germany, pp. 481-491, 1904.
[5] Schlichting H., Boundary-Layer Theory, seventh edition, McGraw-Hill, Book Company, New York, 1979.
[6] Philip M. Gerhart, Richard J. Gross., Fundamentals of fluid mechanics, Addison-Wesley Pub. Co., c1985.
[7] Braza, M. and Chassaing, P. and Ha Minh, H. Numerical study and physical analysis of the pressure and velocity fields in the near wake of a circular cylinder, Journal of Fluid Mechanics 165, pp. 79-130, 1986.
[8] Franke, R. and Rodi, W., and SCHÖNUNG, B., Numerical calculation of laminar vortex-shedding flow past cylinder, Journal of Wind Engineering and Industrial Aerodynamics, 35, pp. 237-257, 1990.
[9] Zhang, H. L. and Ko, N. W. M., Numerical analysis of incompressible flow over smooth and grooved circular cylinders, Computers and Fluids Vol. 25, No. 3, pp. 263-281, 1996.
[10] Lu, X. Y. and Dalton, C., Calculation of the timing of vortex formation from an
oscillating cylinder, Journal of Fluids and Structures 10, pp. 527-541, 1996.
[11] Modi, V. J., Moving surface boundary-layer control:a review, Journal of Fluids and Structures, 11, pp. 627-663, 1997.
[12] Young, D. L. and Huang, J. L. and Eldho, T. I., Numerical simulation of high-Reynolds number flow around circular cylinders by a three-step FEM-BEM model, International Journal for numerical methods in fluids 37, pp.657-689, 2001.
[13] Alvarez-Calderon, A. and Arnold, F. R. A study of the aerodynamic characteristics of a high lift device based on rotating cylinder flap, Technical Report RCF-I , Stanford University ,Palo Alto , U. S. A. , 1961.
[14] Brooks, J. D., Effect of a rotating cylinder at the leading and trailing edges of a hydrofoil, NAVWEPS Report 8042, U. S. Naval Ordinance Test Station, U. S. A.,1963.
[15] Steele, B. N. and Harding, M. H., The application of rotating cylinders to ship
maneuvering, Report No. 148, National Physical Laboratory, Ship Division, U. K., 1970.
[16] Tennant, J. S., A subsonic diffuser with moving walls for boundary-layer control, AIAA Journal 11, pp. 240-242, 1973.
[17] Johnson, W. S. and Tennant, J. S. and Stamps, R. E., Leading edge rotating cylinder for boundary-layer control on lifting surfaces, AIAA Journal of Hydronautics 9, pp. 76-78, 1975.
[18] Tennant, J. S.and Johnson, W. S. and Korthapalli, A., Rotating cylinder for circulation control on an airfoil, AIAA Journal of Hydronautics 10, pp. 102-105, 1976.