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研究生:吳宗祐
研究生(外文):Tzung-You Wu
論文名稱:半橢圓球內膜狀凝結熱傳之熱力學第二定律分析
論文名稱(外文):Thermodynamic Second Law Analysis of Film Condensation from Vapor Flowing Slowly Inside a Semi-Ellipsoid
指導教授:楊勝安楊勝安引用關係
指導教授(外文):Sheng-An Yang
學位類別:碩士
校院名稱:國立高雄應用科技大學
系所名稱:模具工程系
學門:工程學門
學類:機械工程學類
論文種類:學術論文
論文出版年:2009
畢業學年度:97
語文別:中文
論文頁數:88
中文關鍵詞:膜狀凝結半橢圓球CFD體積分率法(VOF)
外文關鍵詞:Film CondensationEntropySemi-EllipsoidCFDVOF
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本文旨在研究一緩慢飽和蒸汽由下往上流經半橢圓球內表面具等壁溫之膜狀凝結熵增分析。於文獻上可知直立長軸橢圓管外的凝結熱傳性能優於圓管外的凝結熱傳性能,故值得吾人探討半橢圓球內之層流凝結熱傳問題。參考Adrian Bejan學者所提出熵增最佳化方法,首先,以理論解析方法探討半橢圓球內表面膜狀凝結之局部與平均熵增率,歸納出無因次的重要參數:Brinkman參數、Rayleigh參數等,瞭解是由熱傳或流體摩擦所引起的熵增後,藉由改變不同幾何離心率、表面張力參數探討對熵增的影響。結果顯示熵增率會隨著離心率、Brinkman、Rayleigh參數的增加而遞增;並隨表面張力的增加而遞減,且由熱傳來主導整個熵增系統。然而,考量CFD-計算流體力學模擬的優點能夠更加節省時間及成本外,在模擬過程中也能增加對本系統的理解。模擬時,採用體積分率法VOF ( Volume Of Fluid )來分析二相流問題,比對模擬所得之解與理論解析之解後,驗證了數值模擬的可行性,可作為未來設計相關熱管、冷凝器之參考依據。
The present paper aims to perform the entropy generation analysis of film condensation from saturated vapor flowing slowly inside an isothermal vertical semi-ellipsoid. Previous literature shows that the condensation heat transfer performance of the elliptical tube with vertical major axis is better then that of circular tube. Thus, it is worth investigating the condensation heat transfer and thermodynamics second law analysis for vapor flowing inside a vertical semi-ellipsoid. The dependent working parameters of the local and average entropy generation caused by heat transfer and film flow friction are found to be Brinkman, Rayleigh, Bond, and geometric parameters. Based on Adrian Bejan entropy generation minimization technique, the result shows that local entropy generation rate increases with eccentricity, Brinkman, Rayleigh parameters, but decreases with the increase of surface tension. Furthermore, the heat transfer irreversibility dominates over the friction irreversibility in the upper half of a Semi-Ellipsoid. With the advantages of more time and cost savings for using CFD-Computational Fluid Dynamics to understand the system, VOF method is used to simulate two-phase flow problem and to verify the feasibility of numerical simulation compared with the solution of theoretical analysis. In the future, the present result can be used as a reference for the design of heat pipe and the condenser.
目 錄
摘 要 I
ABSTRACT II
誌 謝 IV
目 錄 V
圖目錄 VII
符號說明 IX
第一章 緒論 1
1-4-1 幾何表面形狀對膜狀結熱傳遞文獻 4
1-4-2 熱力學第二定律之膜狀凝結熱傳遞文獻 5
第二章 半橢圓球內座標系建立 8
2-1 半橢圓極座標建立 8
2-2 半橢圓球表面張力座標系建立與推導 10
第三章 等壁溫半橢圓球內凝結之熱力第二定律分析 12
3-1 局部熵增方程式之建立與求解 12
3-2 平均熵增方程式之建立與求解 18
3-3 結果與討論 20
第四章 運用 CFD –FLUENT 泛用流體力學套裝軟體驗證 31
4-2-1 網格建構 35
4-2-2 基本假設 37
4-2-3 半橢圓球內凝結熱傳之控制方程 37
4-2-4 工作流體物理性質參數設定 43
4-2-5 模型選擇 46
4-2-6 控制方程的離散方法 47
4-2-7 邊界條件 51
4-2-8 初始猜測值的輸入 54
4-2-9 收斂的準則 55
第五章 結論與建議 80
參考文獻 83
附錄A 86
簡 歷 88
[1]. Nusselt, W., 1916, Die oberflachen kondensation des wasserdampers, Zeitsehriftdes-vereines eutsher ingenieure, Vol.60, pp.541–546, 569-575.
[2]. Rohsenow, W. M., 1956, "Heat transfer and temperature distribution in laminar film condensation ", Trans ASME Vol.78, pp.1645-1648.
[3]. Sparrow, E. M. and Gregg, J. L. ,1959, "Laminar condensation heat transfer on a horizontal cylinder ",Trans ASME, J. Heat Transfer, Vol. 81, pp. 291-296.
[4]. M. M. Chen, 1961, "An analytical study of laminar film condensation: part 2-single and multiple horizontal tubes", J. Heat Transfers, Vol.83C pp.55-60.
[5]. J. C. Y. Koh, Sparrow, E. M. and Hartnett, J. P., 1961, "The two phase boundary layer in laminar film condensation", Int. J. Heat Mass Transfer ,Vol.2, pp.69-82 .
[6]. Krupiczka, R. ,1985,"Effect of surface tension on laminar film condensation on a horizontal cyclinder", Chem.Engng. Process. , Vol. 19, pp. 199-203 .
[7]. S. W. Churchill, 1986, "Laminar film condensation", Int. J. Heat Mass Transfer Vol.29, pp.1219-1226.
[8]. K. Taghavi, 1988, "Effect of surface curvature on laminar film condensation", J.Heat Transfer, Vol.110, pp.268-270.
[9]. Stepanek, J. Heyberger, A.. and Vesely, V., 1969,"Warme-ubergang am WagrechtenRohrbei Kondensation gesattiger und Uberhitzer Dampfe", Int. J.Heat Mass Vol.12, pp.137~146.
[10]. V. K. Dhir and J. H. Lienhard, 1971, "Laminar film condensation on plane and axi-symmetric bodies in non-uniform gravity", Trans. ASME. J. Heat Transfer,Vol.93, No.1 pp.97-100.
[11]. Ali, A. F. M., and McDonald, T. W. ,1977,"Laminar film condensation on horizontal elliptical cylinders: A first approximation for condensation on inclined tubes", ASHRAE Trans. Vol. 83 (2), pp. 242-249
[12]. Karimi, A. ,1977,"Laminar film condensation on helical reflux condensers and related configurations", Int. J. Heat and Mass Transfer, Vol. 20, pp. 1137-1144.
[13]. Souza-Santos, Marcio L. de. ,1990,"Explicit forms for the calculation of heat and momentum transfercoefficients for vapour condensation on surfaces of-various forms", Canadian J. of Chem. Engng. , Vol. 68, pp. 29-37.
[14]. Semenov, V. P.; Shkiover, G. G.; Usachev, A. M. and Semenova, T.P. ,1990,"Enhancement of heatTransfer in condensation of steam on a horizontal 44 non-circular pipe", Heat Transfer-Soviet Research, Vol. 22, No.l, pp. 15-20
[15]. Sheng-An Yang and C. K. Chen, 1993, "Role of Surface Tension and Ellipticity in Laminar Film Condensation on Horizontal Elliptical Tube", Int. J. Heat & Mass Transfer,Vol.36, No.12, pp.3135-3141.
[16]. Sheng-An Yang and Cha'O-Kuang Chen, 1993, "Transient film condensation on a horizontal elliptical tube", J. Phys-D,Vol.26,pp.793-797.
[17]. S. A. Yang and C.K. Chen, 1993, "Laminar Film Condensation on a Horizontal Elliptical Tube with Uniform Surface Heat Flux and Suction at the Porous Wall", J. CSME,Vol.14, No.1,pp.93-100.
[18]. S. A. Yang, 1993, "Investigation of filmwise condensation heat transfer on horizontal plates,elliptical tubes and ellipsoidds",國立成功大學,全國博碩士論文.
[19]. M. Mosaad, 2001, "Mixed-convection laminar film condensation on an incline elliptical tube", J. of Heat Transfer, Vol.123, pp.294-300.
[20]. Li,Guan-Cyun and Yang, Sheng-An, to appear in 2006,"thermodynamic analysis of Free convection Film Condensation on an elliptical cylinder", J. of The Chinese Institute Engineers.
[21]. Bejan, A. 1979, "A studay of entropy generation in fundamental convective heat transfer", J. Heat Mass Transfer, Vol.21, pp.718-725.
[22]. Bejan, A. ,1996, "Entropy generation minimization", chap. 4, CRC Press, Boca Raton, New York.
[23]. G. C. Li, and S. A. Yang, 2006, "Thermodynamic Analysis of Free Convection Film Condensation on an Elliptical Cylinder", J. of the Chinese Institute Engineers.
[24]. G. C. Li, and S. A. Yang, 2007, "Entropy Generation Minimization of Free Convection Film Condensation on an Elliptical Cylinder", Submit to Int. J.Thermal Sciences, Vol.46, pp.407-412.
[25]. 洪任儀、楊勝安,2006,橢圓球外層流膜狀凝結之熱傳與熵增分析,第二十三屆機械工程研討會.
[26]. 陳柏璁,2006,水平橢圓管外強制對流膜狀凝結之熱力第二定律分析,國立高雄應用科技大學,全國博碩士論文.
[27]. 林原慶、鄭宗明、楊勝安,2007,傾斜橢圓管外層流膜狀凝結熱傳之熵增分析,第二十四屆機械工程研討會。
[28]. 何盈毅、陳維邦、楊勝安,2007,圓球表面具定值熱傳率膜狀凝結之熱力 第二定律分析,第二十四屆機械工程研討會。
[29]. 陳維邦、呂俊德、楊勝安,2007,水平圓管等熱通量膜狀凝結之熵增分析,第三十一屆力學研討會。
[30]. Amro M. Al-Qutub ,2001,"Entropy generation in transpiration cooling of concentric spherical shells" ,Exergy Volume: 1, Issue: 4 pp. 303-309
[31]. Lee W H. 1980, "Pressure iteration scheme for two-phase flow modeling. In Multiphase Transport Fundamentals, Reactor Safety, Applications", Vol.1, Veziroglu TN(ed.), Hemisphere Publishing: Washington, DC, pp.407-431
[32]. FLUENT Inc., FLUENT 6.0 User’s Guide, 2001
[33]. FLUENT Inc., GAMBIT 2 User’s Guide, 2001
[34]. Van doormaal, J. P. and Raithby, G. D., “Enhancement of the SIMPLE method for predicting incompressible fluid flow,” Numerical Heat Transfer, Vol.7,pp.147-163, 1984.
[35]. 王福軍,計算流體動力學分析-CFD軟件原理與應用,清華大學出版 社,2005
[36]. 韓占忠,王敬,藍小平,FLUENT流體工程仿真計算實例與應用,北京理工大學出版社
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