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研究生:黃正男
研究生(外文):Cheng-Nan Huang
論文名稱:矩形管道中流體經有限平板質源(陰極)的混合對流實驗研究
論文名稱(外文):Mixed Solutal Convection in the Duct Flow Passing Through a Channelwith an Inclined finite Flat Plate Source(Cathode)
指導教授:王立文王立文引用關係
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:2007
畢業學年度:95
語文別:中文
論文頁數:84
中文關鍵詞:熱質強制對流矩形管道有限平板
外文關鍵詞:mixed convectionfinite flat platerectangular channelelectrochemical system
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在熱流現象的研究上,自然、混合、強制對流三種機制常為學術研究上的重
點,其中以混合對流因兼具其他兩者效應而常被提出來討論。
在實驗中伴隨著質傳因素的影響,將使得流場型態更為複雜;流體從不同的
極性所產生出來的次流體將有濃度上的差異,將有別於一般純流體的流動。
本實驗研究是將有限平板狀質源的質量傳遞引入矩形管道主流中,在不同的
有限平板傾斜角度與水道傾斜角度、強制對流效應針對上銅板為陽極與有限平板
為陰極來進行質混合對流研究。在此,混合對流係指利用幫浦所造成的強制對流
(forced convection),在速度完全發展之後,再與質源傳遞所形成的自然對流
(natural convection)合併之流體運動現象。
實驗使用的工作流體為硫酸銅水溶液(CuSO4 + H2SO4 + H2O),藉由電化學系
統於測試區(test section)之銅板與水道中之平板加上端電壓,使其成為電極,達
成濃度梯度之建立。
實驗採用雷射光暗影法(shadowgraph)作流場結構觀察及照相記錄,並作質
量傳遞率的量測。無因次參數範圍如下:Ar=1 ,Sc=1700~2400,Re=50~300,
Grm=1.67×105,(Reb= 10~60,Grm* =2.09×104) ,θ= -15°~15°,ψ= -10°~10°, b/
H =0.2(有限平板寬度與管道高度比), w/ b = 8(有限平板長寬比)。
質傳遞率量測方面,可清楚的發現質傳遞率Sh 數與Re 數成線性關係;在賦
予有限平板角度(ψ≠0°)時,Sh 值大於有限平板角度(ψ=0°),而有限平板角
度ψ=-15°時,Sh 值為最大;更改陽極質源位置時,隨著水道傾斜角度θ 的改變,
Sh 數也將有不同的大小。
An experimental investigation of mixed solutal convection in the duct flow passing
through a channel with an inclined finite flat plate source(cathode). With the mass
transport factor on the channel flow, the flow patterns have become more complex. The
fluids from the anode or the cathode are denser or less dense so that they do not match
the flow patterns in the pure fluid dynamics. Seldom research can be found on this
subject.
An experimental study of mixed convection with CuSO4+ H2SO4 + H2O solution
in the inclined channel is performed. The shadowgraph technique is used to visualize
the flow and to determine the nature and effect of solutal driven secondary flows in the
inclined channel with the an inclined finite flat plate sources(cathode) inside. The
ranges of the parameters in the present work are : Ar=1 , Sc=1700~2400,
Re=50~300,Grm=1.67×105,(Reb= 10~60,Grm* =2.09×104) ,θ= -15°~15°,ψ
= -10°~10°, b/ H =0.2, w/ b = 8。
Some results about the mass transfer rate are also clearly found. With increasing
the Reynolds number, the corresponding Sherwood number is increasing, for the
Reynolds number is directly proportional to the Sherwood number. When the finite flat
plate is inclined , the corresponding Sherwood number is increasing, the angle of the
finite flat plateψ=-10°, the larger Sherwood number can be.
While changing anode position, because the inclination angle changes, Sherwood
number will also have different values.
中文摘要...................................................i
英文摘要..................................................ii
誌謝.....................................................iii
目錄......................................................iv
圖目錄...................................................vii
符號說
明.................................................ivii
一、前言....................................................1
1.1 研究動機............................................1
1.2 文獻探討............................................3
1.3 研究目的............................................8
二、實驗方法及設備設計......................................9
2.1 實驗方法............................................9
2.1.1 座標設定與統御方程式............................9
2.1.2 無因次化參數...................................10
2.2 設備設計...........................................11
2.2.1 流體循環系統...................................11
2.2.2 實驗週邊系統...................................14
三、參數量測與實驗步驟.....................................19
3.1 參數量測...........................................19
3.2 實驗步驟...........................................21
v
四、實驗結果與討論.........................................22
4.1 實驗區的邊界條件....................................22
4.2 雷射光暗影法之流場型態分析..........................24
4.2.1 Case(A): 上銅板陽極,有限平板(陰極)ψ=0°,下平板
壓克力之流場型態...................................24
4.2.2 Case(B): 上銅板陽極,有限平板(陰極)ψ=10°,下平
板壓克力之流場型態.................................32
4.2.3 Case(C): 上銅板陽極,有限平板(陰極)ψ=-10°,下平
板壓克力之流場型態.................................40
4.2.4 Case(D): 上平板壓克力,有限平板(陰極)ψ=0°,下銅
板陽極之流場型態...................................48
4.2.5 Case(E): 上平板壓克力,有限平板(陰極)ψ=10°,下
銅板陽極之流場型態.................................56
4.2.6 Case(F): 上平板壓克力,有限平板(陰極)ψ=0°,下銅
板陽極之流場型態 ..................................64
4.3 質傳遞率量測結果....................................72
4.3.1 Case(A): 上銅板陽極,有限平板(陰極)ψ=0°,下平板
壓克力之Re 與Sh 相關性........... ...................72
vi

4.3.2 Case(B): 上銅板陽極,有限平板(陰極)ψ=10°,下平
板壓克力之Re 與Sh 相關性.......................... ..73
4.3.3 Case(C): 上銅板陽極,有限平板(陰極)ψ=-10°,下平
板壓克力之Re 與Sh 相關性...................... ......74
4.3.4 Case(D): 上平板壓克力,有限平板(陰極)ψ=0°,下銅
板陽極之Re 與Sh 相關性..............................75
4.3.5 Case(E): 上平板壓克力,有限平板(陰極)ψ=10°,下
銅板陽極之Re 與Sh 相關性 ...........................76
4.3.6 Case(F): 上平板壓克力,有限平板(陰極)ψ=10°,下
銅板陽極之Re與Sh 相關性...................... ......77
五、結論............................................. ......78
5.1 流場型態觀察與分析........................... .......78
5.1.1 Reynolds 數的影響..............................78
5.1.2 水道角度θ的影響...............................79
5.1.3 有限平板角度ψ的影響...........................79
5.1.4 改變陽極質源的影響.............................80
5.2 質傳遞率分析........................................ 81
六、參考文獻........ .......................................82
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