Please use this identifier to cite or link to this item: `http://hdl.handle.net/11455/1674`
 標題: 方柱於限制流場中之數值模擬A Numerical Study of Confined Flow Around a Square Cylinder 作者: 王振忠Wang, Jeng-Jong 關鍵字: Cylinder;方柱;Confined Flow;限制流場 出版社: 機械工程學系 摘要: 摘 要本文的主題為探討平行管道中流體流經單一方柱流場之特性，如方柱所 受阻力，渦流脫落現象及尾流型態等。本文應用了流體力學SIMPLE ( Semi-Implicit Method for Pressure-Linked Equation )方法對上述問 題之控制方程進行求解。對方柱於限制流場中之計算，吾以固定雷諾 數1000，且選擇方柱與平行管中下壁面不同之距離(h/d=0.5，0.7，1.0 ，2.0，3.0，4.5) 加以探討。數值結果發現，當h/d>0.7時，在方柱後方 兩端會有交互渦流脫落的情形，其平均阻力係數 隨h/d之增加而愈緩慢變 小，而平均升力係數 則隨h/d之增加而由負值漸漸驅近至0(h/d=4.5)。在 這h/d範圍內的史卓赫數大約在0.12~0.13間。當h/d=0.5時，則沒有渦流 脫落現象，史卓赫數無法可得，且平均阻力係數值相對其他較高h/d的值 小很多，平均升力係數值則遠大於其他較高h/d的結果。ABSTRACTThe major goal of this paper is to study the characteristics of flow past a single square cylinder that is placed in a horizontal channel. The fluid dynamic SIMPLE (Semi- Implicit Method for Pressure-Linked Equation) was employedto solve the governing equations to obtain the drag and lift force of the cylinder. The vortex shedding phenomena and the associated wake patterns wereexamined. The calculations were performed at a fixed Reynold number of 1000 based on the side of the cylinder. The vertical distance between the center ofcylinder and the bottom wall of the channel was varied in the range 0.5 behind the cylinder for 0.7 to 0.13. For 0.7 slowly decrease with increasly h/d, and the lift coefficient increase with increasly h/d. At h/d=0.5,the flow appeared to be steady withoutany form of vortex shedding, causing a much lower and higher than other casesof larger h/d. URI: http://hdl.handle.net/11455/1674 Appears in Collections: 機械工程學系所