跳到主要內容

臺灣博碩士論文加值系統

(3.95.131.146) 您好!臺灣時間:2021/07/29 02:35
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

: 
twitterline
研究生:曾博聖
研究生(外文):Bo-Sheng Tzeng
論文名稱:具低展弦比矩形阻礙物之封閉盒內的熱質自然對流現象探討
論文名稱(外文):Natural Convection Heat and Mass Transfer in an Enclosure with a Low Aspect Ratio Block
指導教授:王立文王立文引用關係
指導教授(外文):Lin-Wen Wang
學位類別:碩士
校院名稱:元智大學
系所名稱:機械工程學系
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:161
中文關鍵詞:自然對流熱質傳阻礙物
外文關鍵詞:Natural ConvectionHeat and Mass TransferBlock
相關次數:
  • 被引用被引用:1
  • 點閱點閱:119
  • 評分評分:
  • 下載下載:2
  • 收藏至我的研究室書目清單書目收藏:0
本研究主要乃藉由實驗方法來探討具低展弦比矩形阻礙物之封閉盒,其由溫度梯度和濃度梯度所引起的熱質自然對流現象。左、右邊界由銅板組成而上下板與阻礙物則為絕緣之壓克力。實驗區域利用其幾何形狀與邊界條件的設計,藉由改變阻礙物位置,使得在實驗中可以觀察到阻礙物在不同位置的情況,並針對相關無因次參數來探討封閉區域內的流場結構。實驗工作流體為硫酸銅水溶液( CuSO4 + H2SO4 + H2O ),溫度梯度由兩台恆溫水槽維持,濃度梯度則由電化學系統來建立,並於銅板加上端壓,使其成為電極造成濃度梯度。對於封閉盒內流場現象,乃是採用雷射光暗影法(shadowgraphy)來觀察流場,並以相機拍照紀錄分析。為了瞭解流場結構,對流場的溫度極濃度分佈亦做量測。最後,對於質傳遞率Sh與Grm、Grt之關係也做量測與分析。
實驗結果顯示當阻礙物位置位於中間靠左壁或右壁時,上層的流層超過一定時間會有崩解的現象產生。
The purpose of present study is to investigate flow pattern, temperature and concentration distributions resulting from buoyancy force due to a combination of temperature and species convection effects in an enclosure with low aspect ratio block. To change the block location is main objective in this study.

In this experiment, the temperature and the concentration differences are made between two right and left copper walls and the block is made of Plexiglas to simulate. Cupric Sulphate solution is selected as the working fluid. Two constant temperature baths keep the temperature gradient. Concentration gradient is controlled via electrochemical system. The temperature and concentration gradient were imposed in such a way that their effects on the flow were either cooperating or opposing. In order to visualize the flow, the shadowgraph technique is used. Electrical measurement will be used to obtain mass transfer rates and to infer a Sherwood numbers.

To understand the flow structure, the temperature distribution and concentration distribution will be investigated. Finally, the correlations between Sherwood number and solutal concentration Grashof number and thermal Grashof number are also needed to be analyzed.

The results show the upper flow layer in the enclosure will collapse after a period of time if the block locates at the center right or the center left.
書面頁 i
論文口試委員審定書 ii
授權書 iii
中文摘要 iv
文摘要 v
致謝 vi
目錄 vii
圖目錄 xi
符號說明 xvii
一、 前言 1
二、 實驗設計與方法 5
2.1. 溫度梯度的建立 5
2.2. 濃度梯度的建立 5
2.3. 實驗裝置 7
2.4. 實驗過程 8
2.5. 流場觀察 9
2.5.1. 雷射光暗影法 9
2.5.2. 溫度量測 10
2.5.3. 濃度量測 10
三、 實驗結果與討論 12
3.1. 流場整體結構 12
3.2. 雷射光暗影法之流場型態分析 13
3.2.1. D1*=0.125,D2*=0.625 13
(1) Case1-1-1順向流場 13
(2) Case2-1-1逆向流場 14
3.2.2. D1*=0.25、D2* =0.625, 14
(1) Case1-1-2順向流場 14
(2) Case2-1-2逆向流場 15
3.2.3. D1*=0.375、D2* =0.625, 16
(1) Case1-1-3順向流場 16
(2) Case2-1-3逆向流場 16
3.2.4. D1*=0.125、D2* =0.375 17
(1) Case1-2-1 順向流場 17
(2) Case2-2-1 逆向流場 18
3.2.5. D1*=0.25、D2* =0.375 18
(1) Case1-2-2 順向流場 18
(2) Case2-2-2 逆向流場 19
3.2.6. D1*=0.375,D2* =0.375 19
(1) Case1-2-3 順向流場 19
(2) Case2-2-3 逆向流場 20
3.2.7. D1*=0.125、D2* =0.125 21
(1) Case1-3-1 順向流場 21
(2) Case2-3-1 逆向流場 21
3.2.8. D1*=0.25、D2* =0.125 22
(1) Case1-3-2 順向流場 22
(2) Case2-3-2 逆向流場 23
3.2.9. D1*=0.375、D2* =0.125 23
(1) Case1-3-3 順向流場 23
(2) Case2-3-3 逆向流場 24
3.3. 流場溫度分佈 25
3.3.1. D1*=0.125,D2*=0.625 25
(1) Case1-1-1順向流場 25
(2) Case2-1-1逆向流場 25
3.3.2. D1*=0.25,D2*=0.625 26
(1) Case1-1-2順向流場 26
(2) Case2-1-2逆向流場 26
3.3.3. D1*=0.375,D2*=0.625 26
(1) Case1-1-3順向流場 26
(2) Case2-1-3逆向流場 27
3.3.4. D1*=0.125,D2*=0.375 27
(1) Case1-2-1順向流場 27
(2) Case2-2-1逆向流場 27
3.3.5. D1*=0.25,D2*=0.375 28
(1) Case1-2-2順向流場 28
(2) Case2-2-2逆向流場 28
3.3.6. D1*=0.375,D2*=0.375 28
(1) Case1-2-3順向流場 28
(2) Case2-2-3逆向流場 29
3.3.7. D1*=0.125,D2*=0.125 29
(1) Case1-3-1順向流場 29
(2) Case2-3-1逆向流場 29
3.3.8. D1*=0.25,D2*=0.125 30
(1) Case1-3-2順向流場 30
(2) Case2-3-2逆向流場 30
3.3.9. D1*=0.375,D2*=0.125 30
(1) Case1-3-3順向流場 30
(2) Case2-3-3逆向流場 31
3.4. 流場濃度分佈 31
3.4.1. D1*=0.125,D2*=0.625, 31
(1) Case1-1-1順向流場 31
(2) Case2-1-1順向流場 32
3.4.2. D1*=0.25,D2*=0.625 32
(1) Case1-1-2順向流場 32
(2) Case2-1-2逆向流場 32
3.4.3. D1*=0.375,D2*=0.625 33
(1) Case1-1-3順向流場 33
(2) Case2-1-3逆向流場 33
3.4.4. D1*=0.125,D2*=0.375 33
(1) Case1-2-1順向流場 33
(2) Case2-2-1逆向流場 34
3.4.5. D1*=0.25,D2*=0.375 34
(1) Case1-2-3順向流場 34
(2) Case2-2-2逆向流場 34
3.4.6. D1*=0.375,D2*=0.375, 35
(1) Case1-2-3順向流場 35
(2) Case2-2-3逆向流場 35
3.4.7. D1*=0.125,D2*=0.125 35
(1) Case1-3-1順向流場 35
(2) Case2-3-1逆向流場 36
3.4.8. D1*=0.25,D2*=0.125 36
(1) Case1-3-2順向流場 36
(2) Case2-3-2逆向流場 37
3.4.9. D1*=0.375,D2*=0.125 37
(1) Case1-3-3順向流場 37
(2) Case2-3-3逆向流場 37
3.5. 無因次質傳遞率Sh值分析 38
3.5.1. Sh與Grt之關係 38
3.5.2. Sh與熱質順向、逆向之關係 39
四、 結論 40
4.1. 流場形態分佈 40
4.2. 流場溫度分佈 41
4.3. 流場濃度分佈 41
4.4. 無因次質傳遞率 41
4.5. 與蔡宏源【25】不同位置之阻礙物比較 42
4.6. 相同Grm、Grt與高展弦比矩形阻礙物比較 42
參考文獻 43
1.S. Ostrach, "Natural Convection with Combined Buoyancy Forces", Physico Chem. Hydrodyn, Vol.1, pp.233-247, (1980).
2.H. Stommel, A. B. Arons and D. Blanchard, "An Ocean Graphical Curiosity the Perpetual Salt Fountain", Deep. Sea Res., Vol.15, pp.275-280, (1956).
3.J.S. Turner, "The Behavior of a Stable Salinity Gradient Heat from Below", J. Fluid Mech. Vol.33, pp.183-200, (1968).
4.Y. Kamotani, L.W. Wang, S. Ostrach and H.D. Jiang, "Experimental Study of Natural Convection in Shallow Enclosures with Horizontal Temperature and Concentration Gradients", Int. J. Heat Mass Transfer, Vol.28, No.1, pp.165-173, (1985)
5.C.R. Wilke, M. Eisenberg and C.W. Tobias, "Correlation of Limiting Currents under Free Convection Conditions", J. of the Electrochemical Society, Vol.100, pp.513-523, (1953).
6.L.W. Wang and D.J. Sun, "Convection Mass Transfer in Enclosures with Vertical Temperature and Concentration" J. of National Cheng-Kung University, Vol.20, pp.313-322, (1985).
7.V.G. Levich, "Physicochemical Hydrodynamics (1st edition) ", pp.281 Prentice-Hall, Englewood Cliffs nj, (1962).
8.T. Mizushina, "The Electrochemical Method in Transport Phenomena", Adv. Heat Transfer, Vol. 7, pp.87-161, (1971).proc. heat transfer fluid mech. inst. pp.63-78, (1966).
9.L.W. Wang and C.C. Chou, "Experimental Study of Natural Convection Heat and Mass Transfer in an Enclosure with a Cold Inner Cylinder", Experimental Heat Transfer, Vol.4, pp.367-380, (1991).
10.J.chang, T.F. Lin and C.H. Chien, "Unsteady Thermosolatal Opposing Convection of A Lique-Water Mixture in a square Cavity-I, Flow Formation and Heat and Mass Transfer Characteristics", Int. J. of Heat and Mass Transfer.Vol.36, No.5, pp.1315-1331(1993)
11.C. Gau and K.H. Wu, "A Nonuntrusive Technique for Concentration Distribution Measurement in an Enclosure", Experiment Heat Transfer, Vol. 2, pp.215-226, (1989).
12.N.N.Lin, and Adrian Bejan, "Natural Convection in a Partially Divided Enclosure", Int. J. of Heat and Mass Transfer.Vol.26,No.12,pp.1867-1878(1983).
13.H.I. Abu-Mulaweh, B.F. Armaly and T.S. Chen, "Measurements in Buoyancy- Opposing Laminar Flow Over a Vertical Backward-Facing Step”, J Heat transfer, Vol. 116, pp.247-250(1994).
14.Orhan Aydin, "Natural convection in a differentially heated enclosure filled with a micropolar fluid", International Journal of Thermal Sciences. 46 pp.963-969(2007).
15.Prasad Bhave , Arunn Narasimhan , D.A.S Ress, "Natural Convection Heat Transfer Enhancement using Adiabatic Block:Optimal Block size and Prandtl Number Effect", Int. J. of Heat and Mass Transfer.49 pp.3807-3818 (2006).
16.Manab Kumar Das , K. Saran Kumar Reddy, "Conjugate Natural Convection Heat Transfer in an Inclind Square Cavity Containing a Conducting Block", Int. J. of Heat and Mass Transfer. 49 pp.4987-5000, (2006).
17.Shohel Mahmud, "Free Convection inside an L-Shaped Enclosure", Int. Comm. Heat Mass Transfer.29 pp.1005-1013 (2002).
18.Xuegeng Yang , Kerstin Eckert , Armin Heinze , Margitta Uhlemann , "The Concentration Field During Transient Natural Convection between Vertical Electrodes in a Small Aspect Ratio Cell "J. of Electroanalytical Chemistry (2007).
19.Ali a. Merrikh, "Natural convection in an enclosure with disconnected and conducting solid blocks" , Int. J. of Heat and Mass Transfer.48 pp.1361-1372(2005)
20.Mohammed Jami, "Lattice Blotzmann method applied to the laminar natural convection in an enclosure with a heat-generating cylinder conducting body" , International Journal of Thermal Sciences. 46 pp.38-47(2007).
21.Qi-hong Deng, "Fluid flow and heat transfer characteristics of natural convection in square cavities due to discrete source-sink pairs" , Int. J. of Heat and Mass Transfer.51 pp.5949-5957(2008).
22.Nawaf H. Saeid, "Transient free convection in a square cavity filled with a porous medium", Int. J. of Heat and Mass Transfer. 47 pp.1917-1924(2004).
23.康明方,「具階梯之封閉盒的熱質自然對流現象探討」,私立元智大學,碩士論文,民國93年。
24.郭進倫,「熱質源壁具雙凸塊之密閉盒的熱質對流現象研究」,私立元智大學,碩士論文,民國95年。
25.蔡宏源,「封閉盒中不同位置之阻礙物對熱質自然對流的影響與探討」,私立元智大學,碩士論文,民國97年。
26.許智豪,「具高展弦比矩形阻礙物之封閉盒內熱質自然對流」,私立元智大學,碩士論文,民國98年。
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top