Please use this identifier to cite or link to this item: `http://hdl.handle.net/11455/1672`
 標題: 單方柱暫態流場之數值模擬Numerical Simulation of Transient Flow Past Rectangular Cylinder 作者: 林志坪Lin, Chih Ping 關鍵字: rectangular;方柱;cylinder 出版社: 機械工程學系 摘要: 本研究擬藉數值計算方法,探討單方柱瞬間流場之動態發展,及方柱誘導受 力情形.研究結果期能提供深入了解渦流脫落現象,及方柱升阻力之了解. 計算過程中我們利用表面渦度法以模擬固體的邊界,進而使用渦度-速度積 分產生法則,計算黏性流體在整個流場中之瞬間速度.同時藉由物體表層為 渦流之源頭,並產生適當的渦流,以滿足流體於固體表層無滑動速度之邊界 條件,對於渦流於流場中之擴散與傳輸,則以渦度傳輸方程式模擬渦流場之 瞬間性發展.對於方柱流場之計算,我們選取兩種不同雷諾數100,150加以 探討,結果顯示壓力阻力係數和升力係數,隨雷諾數增加而增加,阻力係數 隨雷諾數增加而減少.The main purpose of this study is to analyze dynamical processesof flow field over a single cylinder and also to investigatethe force induced on cylinder.In the research,the vortex sheet is used to simulate the surface of cylinder by enforcing zeronormal component of velocity at the surface.The no-slip conditionis satisfied by producing free vorticity near the surface.Then,the Biot-savart Law of induced vorticities is applied to determinethe velocity.Finally,the transport of free vorticity in the flowfield is determined by solving the vorticity transport equation.In the equation,two Reynolds numbers,which are 100 and 150 are used for the flow over single cylinder.The computational resultsshow that lift and the pressure-drag coefficient increase withReynolds number.But total drag coefficient decrease with Reynoldsnumber. URI: http://hdl.handle.net/11455/1672 Appears in Collections: 機械工程學系所

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