Please use this identifier to cite or link to this item: `http://hdl.handle.net/11455/2257`
 標題: 三維多孔間隙隔板通道之紊流熱傳數值模擬分析Numerical Simulation of Turbulent Heat Transfer in a Three- Dimensional Channel with Porous Baffles 作者: 陳佩孚Chen, Pei-Fu 關鍵字: three-dimensional;三維;porous medium;heat exchanger;多孔性介質;熱交換器;紊流 出版社: 機械工程學系 摘要: 本文利用計算流體力學PHOENICS軟體來模擬一紊流三維渠道內放置多個多孔性隔板流場。採用連續方程式和動量方程式，並配合SIMPLE-C法則與κ-ε雙方程式紊流模式，並以控制體積法建立有限差分方程式。多孔性隔板交插地放置在底部及頂部，並且改變各種物理參數，諸如雷諾數的大小(Re=10000~50000)、多孔隙隔板的孔隙度(0%、20%及42%)、多孔隙隔板的寬度比(w/W= 1/4、1/2、3/4及1)、多孔隙隔板的高度比(h/H= 0.25、0.5及0.75)等等，看看其對平均紐塞數及摩擦係數的影響。 本文結果顯示，當固定隔板高度和雷諾數下，多孔性介質隔板渠道較實心隔板渠道之整體平均紐塞數高出63%~73%。由此可知多孔隙介質隔板渠道的熱傳效果比實心隔板渠道來得好。且實心隔板渠道較多孔性介質隔板渠道的摩擦係數高出65%~81%。故多孔性介質隔板渠道所受到的流場阻力較實心隔板渠道來得小。本文研究結果除可以提供建立起多孔隙隔板在熱交換器內的最佳化設計外，更能對多孔隙介質應用有較深一層的瞭解。In this study , a computational fluid (CFD) code , PHOENICS is used to calculate the three-dimensional nature of turbulent flow in a channel with porous baffles. Owing to the turbulent characteristic by the porous baffles flowfield, the continuity equation , momentum equation , and the k-ε turbulence model are adopted to construct the model with control volume integration for finite difference associated with SIMPLE-C algorithm .The porous baffles are arranged on the bottom and top channel walls in a staggered manner. And we will investigate the various parameters , such as Reynolds number(Re= 10000 to 50000) and the porosity of the baffle (0%,20% and 42%), respectively; the baffle broad ratio (w/W=1/4,1/2,3/4 and 1) and the baffle height ratio (h/H=0.25,0.5 and 0.75). The correlation for the average Nusselt number and friction factor are also developed in terms of flow and baffled parameters . From the present result result , the average Nusselt number of a 3-D duct in the porous baffle is higher about 63~73% than the solid baffle when the baffle height and Reynolds number of flow field are fixed. And the friction factor of solid baffle is higher about 65~81% than the porous baffle. Consequently, the results of the investigation will provide a reference and fundamental optimize design for the porous baffle in the heat exchanger. URI: http://hdl.handle.net/11455/2257 Appears in Collections: 機械工程學系所

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