(3.235.108.188) 您好!臺灣時間:2021/03/07 20:14
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果

詳目顯示:::

我願授權國圖
: 
twitterline
研究生:張永福
研究生(外文):Chang Yung Fu
論文名稱:非達西多孔性介質中考慮熱質傳效應之線熱源自然對流研究
論文名稱(外文):Coupled Heat and Mass Transfer by Natural Convection from the Line Heat Sources in a Non-Darcian Porous Medium
指導教授:林建男林建男引用關係
學位類別:碩士
校院名稱:遠東技術學院
系所名稱:機械研究所
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:2004
畢業學年度:92
語文別:中文
論文頁數:84
中文關鍵詞:速度場熱質傳方程式多孔性濃度場
外文關鍵詞:Coupled Heat
相關次數:
  • 被引用被引用:1
  • 點閱點閱:216
  • 評分評分:系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔
  • 下載下載:21
  • 收藏至我的研究室書目清單書目收藏:0
  本文擬以理論分析及數值模擬探討多孔性介質中考慮熱質傳效應時的煙流自然對流問題,研究的主題包括兩部份:(1)非達西(對流效應、慣性效應)流場中,考慮熱質傳效應的線熱源自由煙流問題之研究。(2)非達西(邊界效應、對流效應、慣性效應)流場中,考慮熱質傳效應的線熱源壁煙流問題之研究。理論分析利用相似轉換理論推導,由於轉換後的統御方程式不存在相似解,因此採用局部相似法(local similaritymethod)搭配六階朗吉─庫塔(Runge Kutta)方法求解。
  由數值結果得知,自由煙流的中心速度、中心溫度及中心濃度隨ξ愈大(愈下游處)而降低。當浮力比(buoyancy ratio) N 增加,中心速度會增加,而中心溫度及濃度值降低,另外N 值對速度場的影響程度隨著路易斯數(Lewis number) Le 的增加而增加,對溫度場及濃度場的影響在Le<1 時比Le>1 時明顯。Le 改變對速度場及濃度場的影響比對溫度場大。N 及Le 對壁煙流流場、溫度場及濃度場的影響相同,但是影響的程度比對自由煙流的情況明顯。
The present study theoretically analyzes a couple heat and mass ransfer by natural convection from the line sources embedded in a non-Darcian porous medium. The contents focus on the two physical models: (1) The natural convection by the free plume in a non-Darcian porous medium (convective and inertia effect included.). (2) The natural convection by the wall plume in a non-Darcian porous medium boundary, convective and inertia effect included.). By employing similarity analysis, there is no existence of similarity solution for the governing equations with the non-Darcian effects included. Then the local similarity method is used to solve the equations in couple with a variable step six-order Runge-Kutta method.
The results indicate that, for the free plume, the tangential peak velocity, maximum temperature and maximum concentration decrease with increasing value of ξ. In the existence of a concentration gradient, convective flow can be either assisted or suppressed, depending on the sign of the buoyancy ratio (N). When the value of N is increased, the peak velocity is increased, but the maximum temperature and maximum concentration are decreased. In addition, the effect of N to velocity profiles is stronger as Lewis number (Le) increases.
The effect of N to the temperature and concentration fields is more significant for Le<1 than for Le>1. The influence of Le on the velocity and concentration fields is more intensive than it on the temperature field. For the results of wall plume, the mass transfer effect on the wall plume is similar, but more pronounced than that on the free plume.
目錄
中文摘要……………………………………………………………………Ⅰ
英文摘要……………………………………………………………………Ⅱ
致謝…………………………………………………………………………Ⅲ
目錄…………………………………………………………………………Ⅳ
圖目錄………………………………………………………………………Ⅵ
符號說明…………………………………………………………………ⅩⅢ
第一章 緒論…………………………………………………………………1
1.1 研究背景及目的……………………………………………………1
1.2 文獻探討……………………………………………………………4
1.3 本文結構及研究方法………………………………………………6
第二章 多孔性介質之簡介…………………………………………………8
2.1 達西定律……………………………………………………………8
2.2 非達西效應…………………………………………………………9
第三章 數學分析………………………………………………………….12
3.1 線熱源自由煙流………………………………………………….12
3.2 線熱源壁煙流…………………………………………………….18
第四章 數值方法………………………………………………………….26
第五章 結果與討論……………………………………………………….30
5.1 線熱源自由煙流………………………………………………….30
5.2 線熱源壁煙流…………………………………………………….33
第六章 結論與建議……………………………………………………….78
參考文獻……………………………………………………………………80
附錄一………………………………………………………………………84
1. H.Darcy, Les Fontaines Publiques de la Vill de Dijon, Victor Dalmont,Paris(1856)
2. J. S., Leu, and J. Y., Jang, “The wall and free plumes above a horizontal line source in a non-Darcian porous medium”, Int. J. Heat Mass Transfer, Vol.37,PP.1925-1933(1994)
3. Y. B. Zeldovich, Zuhr. Exp. Theor. Fiz., Vol.7, p.1463 (1937).
4. C. S. Yih, Free convection due to point heat source, Proc. 1st U. S. National Congr. Appl. Mech., pp.941-974 (1956).
5. C. S. Yih, Free convection due to a line source, Trans. Am. Geophys. Un., Vol.33, pp.669-672 (1962).
6. T. Fujii, Theory of the steady laminar natural convection above a horizontal line heat source and a point heat source, Int. J. Heat Mass Transfer, Vol.3, pp.597-606 (1963).
7. J. C. Mollendorf and B. Gebhart, Axisymmetric natural convection flows resulting from the combined buoyancy effects of thermal and mass
diffusion, Fifth Inter. Heat Transfer Conf., Tokyo (1974).
8. A. V. Appalaswamy and Y. Jaluria, Axisymmetric plume flow in a vertical uniform free stream, J. Appl. Mech., Vol.47, pp.667-669 (1980).
9. D. S. Riley and D. G. Drake, Mixed convection in an axisymmetric buoyant plume, J. Mech. Appl. Math., Vol.36, pp.42-54 (1983).
10. B. Gebhart, L. Pera and A. W. Schorr, Steady laminar nature convection plumes above a horizontal line heat source, Int. J. Heat Mass Transfer, Vol.13, pp.161-171 (1970).
11. H. K. Kuiken and Z. Rotem, Asymptotic solution for plume at very large and small Prandtal numbers, J. of Fluid Mech., Vol.45, pp.585-600 (1970).
12. T. Fujii, I. Morioka and H. Uehara, Buoyant plume above a horizontal line heat source, Int. J. Heat Mass Transfer, Vol.16, pp.755-768 (1973).
13. S. Nakai and T. Okazaki, Heat transfer from a horizontal circular wire at small Reynolds and Grash of numbers-II, Int. J. Heat Mass Transfer, ,pp.397-413 (1975).
14. D.Zimin and Y. N. Lyakhov, Convective wall plume, J. Appl. Mech. Tech. Phys., Vol.11, pp.159-161 (1970).
15. A. J. Liburdy and G. M. Faeth, Theory of a steady laminar thermal plume along a vertical adiabatic wall, Letters in Heat and Mass Transfer, Vol.2, pp.407-418 (1970).
16. Y. Jaluria and B. Gebhart, Buoyancy induced flow arising from a line thermal source on an adiabatic vertical surface, Int. J. Heat Mass Transfer, Vol.20, pp.153-157 (1977).
17. R. A. Wooding, Convection in a saturated porous medium at large Rayleigh number or Peclet number, J. Fluid Mech., Vol.15, pp.527-544 (1963)
18. F. C. Lai, Natural convection from a concentrated heat source in a saturated porous medium, Int. Comm. Heat Mass Transfer, Vol.17, pp.791-800 (1990).
19. N. Afzal and M. Y. Salam, Natural convection from point source embedded in Darcian porous medium, Fluid Dynamic Research, Vol.6, pp.175-184 (1990).
20. M. Kumari, I. Pop and G. Nath, Darcian mixed convection plumes along vertical adiabatic surfaces in a saturated porous medium,
Thermal-and-Fluid Dynamic, Vol.22, pp.173-178 (1988).
21. D. B. Ingham, An exact solution for non-Darcy free convection from a horizontal line source of heat, Thermal-and-Fluid Dynamic, Vol.22, pp.125-127 (1988).
22. F. C. Lai, Non-Darcy natural convection from a line source of heat in saturated porous medium, Int. Comm. Heat Mass Transfer, Vol.18, pp.445-457 (1991).
23. P. Cheng and T. M. Zheng, Mixed convection in the thermal plume above a horizontal line source of heat in a porous medium of infinite extent, Proc. of 8th international Heat transfer Conference, Vol.5, pp.2671-2675 (1986).
24. A.Bejan, and K. R., Khair, Heat and Mass transfer by natural convection in a porous medium, Int.J.Heat Mass Transfer, Vol.28,pp.909-918 (1985).
25. J. Y. Jang and W. J. Chang, Buoyancy-induced inclined boundary layer flow in a porous medium resulting from combined heat and mass buoyancy effects, Int. Comm. Heat Mass Transfer Vol.15, pp.17-30 (1988).
26. J. Y.,Jang, and J. R., Ni, Transient free convection with mass transfer from an isothermal vertical flat plate embedded in a porous medium, Int. J. Heat Fluid Flow, Vol.10,pp.59-65 (1989)
27. D. Poulikakos, On buoyancy induced heat and mass transfer from a concentrated source in an infinite porous medium, Int. J. Heat Mass Transfer, Vol.28,pp.621-629 (1985)
28. S. E. Larson and D. Poulikakos, Double diffusion from a horizontal line source in an infinite porous medium, Int. J. Heat Mass Transfer, Vol.29,pp.492-495 (1986)
29. F. C. Lai, Coupled heat and mass transfer by natural convection from a horizontal line source in saturated porous medium, Int. Comm. Heat Mass Transfer, Vol.17,pp.489-499 (1990)
30. J. C. Slattery, Flow of viscoelastic fluids through porous medium, AIChE J., Vol.13, pp.1066-1071 (1967).
31. S. Whitaker, Diffusion and dispersion in porous medium, AIChE J., Vol.13, pp.420-427 (1967).
32. P. Forchheimer, Wasserbewegung durch Boden, Forschtlft Ver. D. Ing., Vol.45, pp.1782-1788 (1901).
33. K. Vafai and C. L. Tien, Boundary and inertia effects on flow and heat transfer in porous media, Int. J. Heat Mass Transfer, Vol.24, pp.195-203 (1981).
34. H. C. Brinkman, A calculation of the viscous force exerted by a flowing fluid on a dense swarm of particles, Appl. Sci. Res., Vol.1, pp.27-34(1947).
35.T. S. Lundgren, Slow flow through stationary random beds and suspensions of spheres, J. of Fluid Mech., Vol.51, pp.273-299 (1972).
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top
系統版面圖檔 系統版面圖檔