臺灣博碩士論文加值系統

中文摘要
本研究主要在探討非牛頓流體中氣泡的行為及在鼓泡床中的熱傳現象，而主要是以質點影像分析儀(PIA)對二維鼓泡床中單一氣泡及雙氣泡結合時周遭瞬時流場的量測，及以熱傳探針探討非牛頓流體在鼓泡床中之熱傳現象。在單一氣泡中分別探討四種不同形狀大小的氣泡分別為淚滴狀、平版尖端狀、平版狀及圓帽狀。在單一氣泡周遭的流場穩定不隨時間而改變，而在淚滴到平版形狀體積下的氣泡，在尾流區域中無複雜的尾流渦旋生成下拋的情形發生，在這區域取而代之的為非牛頓流體中特殊的現象“負尾流”現象，而這現象一般推測為shearthinning效應及黏彈性效應造成。而這負尾流中液體向下流動的區域在隨著氣泡體積增大形狀改變而邊界漸漸縮小；而到了圓帽狀氣泡的體積大小時，主導流體流動為慣性力，而shearthinning效應與黏彈性效應在此時作用已不大，故在氣泡尾部無負尾流現象的發生而是以與牛頓流體相似液體被氣泡吸引向上，而在有兩個渦旋的穩態封閉尾流。
在氣泡結合方面，可發現氣泡的結合其流場不論是何種氣泡都是依原先兩未碰撞的氣泡流場慢慢接近而相互改變影響，且其變化相當穩定。而從流場的分析又可看出對於氣泡本身速度影響的因素為何，在未進入前方氣泡流場時有著較大的速度是因為前方氣泡通過時造成流體因記憶效應而仍具有shearthinning效應而使後方氣泡通過時會大於原先之速度；在進入前方氣泡所引發的流場中則是因氣泡本身壓力梯度的關係而吸引加速。
非牛頓流體在鼓泡床中的熱傳分佈上，其發現熱傳係數的最高值幾乎都發生在氣泡通過的地方，且氣泡速度越快所能挾帶的液體速度更快，而又因shearthinning效應的雙重影響下，熱傳值會大於無氣泡通過的區域。

Abstract
This work is to study the bubble behavior and heat transfer in a non-Newtonian fluid of a bubble column. The flow fields around the single rising bubble and bubble coalescence are measured qualitatively and quantitatively by particle image analyzer (PIA). Also, the heat transfer coefficient distribution is measured by heat transfer probe. Four kinds of bubble shapes (teardrop, oblate-cusped, oblate and spherical cap) are discussed. The flow field around a bubble rising is steady and doesn’t change with time. For the bubble shape from teardrop to oblate, there is no complex vortex shedding in the wake, and instead of the complex phenomenon is the special phenomenon in non-Newtonian fluid,
"negative wake". This phenomenon is caused by the shearthinning effect and viscoelasticity. The flow in the negative wake area is downward. The boundary of the negative wake shortens with the bubble volume increasing. Then, increase the bubble volume to the spherical cap, and the negative wake is disappeared, and the flow is upward to bubble as in Newtonian fluid. In the spherical cap bubble wake is a steady closed wake with two vortexes. It is because that the inertia force restrains the shearthinning effect and vicoelasticity.
In bubble coalescence, the flow field is changed from two single bubble flow fields weld into one bubble flow field, and the process is stable. After getting the qualitative and quantitative analysis of the flow field as the two bubble coalescence, it classifies the reason that trailing bubble with different rising velocity; when the trailing bubble doesn’t get into the flow flied around leading bubble, the trail bubble with larger rising velocity is because of the fluid with some memory effect holding shearthinning effect. Then bubble get into the flow field around leading bubble is subject to the negative pressure gradient caused it accelerate.
The heat transfer coefficient in the non-Newtonian fluid in bubble column is mostly dependent to the gas flow rate. The larger heat transfer rate is in the bubble cluster, because the bubble cluster carries the fluid flow upward and with larger rising velocity then the region with no bubble pass through. The larger liquid velocity causes the viscosity decreasing in favor of the surface renewal rate faster.

目錄
中文摘要 :
英文摘要 :
目錄 :
符號說明 :
附圖目錄 :
第一章 前言 -------------------------------------------------------------------- 1
1-1 簡介-------------------------------------------------------------------------- 1
1-2 文獻回顧----------------------------------------------------------------------3
1-2.1 非牛頓流體的行為-------------------------------------------------------3
1-2.2 單一氣泡文獻回顧------------------------------------------------------13
1-2.3 氣泡結合文獻回顧------------------------------------------------------21
1-2.4 鼓泡床中熱傳文獻回顧------------------------------------------------23
1-3 研究動機 ------------------------------------------------------------------28
第二章 實驗設備與方法 -----------------------------------------------------30
2-1 選用物質及其流變性質 -------------------------------------------------30
2-2 實驗裝置 -------------------------------------------------------------------32
2-3 質點影像追跡儀PIA ---------------------------------------------------- 38
2-4 實驗步驟及實驗參數 --------------------------------------------------- 43
第三章 結果與討論 ---------------------------------------------------------- 47
3-1 單一氣泡運動之結果討論 --------------------------------------------- 47
3-1.1 單一氣泡在非牛頓流體的流態結構 -------------------------------48
3-1.2 單一氣泡在牛頓流體的流態結構 ----------------------------------61
3-2 在非牛頓流體中兩氣泡結合之流場變化 ---------------------------68
3-2.1 兩相同氣泡結合之流場分析 ----------------------------------------69
3-2.2 小氣泡（後）與大氣泡（前）結合之流場分析 ----------------79
3-2.3 大氣泡（後）與小氣泡結合之流場分析 -------------------------86
3-3 非牛頓流體在二維鼓泡床中之熱傳現象 ----------------------------92
3-3.1 非牛頓流體在二維鼓泡床中之巨觀流態 -------------------------92
3-3.2 非牛頓流體在二維鼓泡床中之熱傳分佈 -------------------------96
第四章 結論與未來展望 ---------------------------------------------------101
參考文獻 ---------------------------------------------------------------------- 104

參考文獻 :
Astarita. G.. and Apuzzo. G., 1965, “Motion of gas bubble in non-Newtonian liquids.”A.I.Ch.E Journal.11.815-820
Acharya. A.. and Ulbrecht. J..,1978, “Note on the influence of viscoelasticity on the coalescence rate of bubbles and drops.” A.I.Ch.E Journal. 24. 348-351
Bisgaard. C.. ,1983, “Velocity fields around spheres and bubbles investigated by laser-Doppler anemometry.” Journal of non-Newtonian fluid Mechanics.12.283-302
Bird R.B. Armstrong R.C. and Hassager O..,1987,“Dynamics of polymeric liquids.” New York: John Wiley and sons press
Coutanceau M.. and Hajjam M..,1982, “Viscoelastic effect on the behaviour of an air bubble rising axially in a tube.” Appl. Sci. Res.38.199-207
Calderbank. P.H. Johnson. D.S.L. and Loudon. J.. ,1970, “Nechanics and mass transfer of single bubbles in free rise through some Newtonian and non-Newtonian liquids.” Chemical Engineering Science.25.235-256
Chen. R. C., and L.-S. Fan, 1992, “Particle Image Velocimertry for Characterizing the Flow Structure in Three-Dimensional Gas-Liquid-Solid Fluidized Bed,” Chemical Engineering Science., 47,3615-3622.
Chen. R. C., I. S. Chou, and L. W. Liou, 1996, “High-Speed Particle Image Analyzer for Characterizing Bubble Wake Dynamics,” ASME Fluids Engineering Division Summer Meeting, San Diego,CA.
Chen. R. C., and I. S. Chou, 1998a, “Wake Structure of a Single Bubble Rising in a Two-Dimensional Column,” Exp. Therm. Fluid Sci, 17, 165-178.
Chen, R. C., and I. S. Chou, 1998b, “Preliminary Studies of Bubble Dynamics Using Particle Image Analyzer,” J. CSME., 19, 475-485.
Clift. R.. Grace. J. R. and Weber. M. E.,1978,“Bubbles,drop and particles” San Diego: Academic press
Chhabra. R.P.,1993, “Bubble, drop and particles in Non-Newtonian fluids.” Boca Raton: CRC press
Chen R.C. Wang F.M. and Lin T.J. ,1999, “Bubble wake dynamics of single bubble rising in the freeboard of a two-dimensional liquid-solid fluidized bed .” Chemical Engineering Science.000. 000-000
Crabtree.J.R. and Bridgwater.J..,1967,“The wake behind two-dimensional air bubble.” Chemical Engineering Science.22 1571-1583
Dekee. D.. and Chhabra. R. P.,1988, “Photographic study of shapes of bubbles and coalescence in non-Newtonian polymer solutions.”Rheol. Acta.27.656-666
Dekee. D.. Carreau. P. J., and Mordarski. J.,1986, “Bubble velocity and coalescence in viscoelastic liquids” Chemical Engineering Science.41. 2273-2286
Dekee. D.. Chhabra. R. P. and Dajan. A..,1990, “Motion and coalescence of gas bubble in non-Newtonian polymer solutions.” Rheol. Acta.27. 656-670
Dewsbury K.. Karamanev. D.. and Margaritis. A.,1999,“Hydrodynamic characteristics of free rise of light solid Particles and gas bubbles in Non-Newtonian liquids” Chemical Engineering Science. 54 .4825-4830
Deckwer. W. D., 1980, “On the Mechanism on Heat Transfer in Bubble Column Reactor,” Chemical Engineering Science. 35,1341-1346.
Funfschilling. D.. and Li. H. Z..,1999, “Flow of non-Newtonian fluids around bubbles : PIV measurements and birefringence visualization.” Chemical Engineering Science.56.1137-1141
Fuller. G.G. and Leal. L.G, 1981, “Flow birefringence of concentrated polymer solutions.” J. Polymer Sci.19.557-587
Franz, K., T. Borner, H. J. Kantorek, and R. Buchholz, 1984, “Flow Structures in Bubble Columns,” Ger. Chem. Eng.,7,365-374.
Hassager. O.. ,1979, “Negative wake behind bubbles in non-Newtonian liquids.”Nature.279.402-403
Kawase Y.. and Moo-Young M..,1987, “Heat transfer in bubble column reactors with Newtonian and non-Newtonian fluids.” Chem.Eng. Res. Des.65.121-126
Kang. Y., and S. D. Kim. 1987, “Heat Transfer Characteristics in Liquid Fluidized Beds,” Hwahak Konghak.,25,81-88
Kumar, S., and L.-S. Fan, 1994, “ Heat Transfer Characteristics in Viscous Gas-Liquid and Gas-Liquid-Solid Systems,” AIChE. J., 40,745-755.
Li. H. Z.. Mouline. Y.. Funfschilling. D.. Marchal. P..Choplin. L.. and Midoux. N.,1998, “Evidence for in-line bubble interactions in non-Newtonian fluids.” Chemical Engineering Science. 53. 2219-2230
Li. H. Z.. Mouline. Y.. Choplin. L.. and Midoux. N.,1997, “Rheological simulation of in-line bubble interaction .”A.I.Ch.E Journal. 43.265-267
Li. H. Z..,1999,“Bubbles in non-Newtonian fluids:Formation, interactions and coalescence.” Chemical Engineering Science.54.2247-2254
Li. H. Z.. Mouline. Y.. Choplin. L.. and Midoux. N.,1997, “Chaotic bubble coalescence in non-Newtonian fluids.” Int.J.Multiphase flow. 23.713-72
Lin T. -J., J. Reese, T. Hong, and L.-S. Fan, 1996, “Quantitative Analysis and Computation of Two-Dimensional Bubble Columns,” AIChE J., 42,301-318.
Marrucci. G.., 1969,“A theory of coalescence” Chemical Engineering Science. 24 .975-988
Ruckenstein. E.. and Smigelschi. O..,1965, “Heat transfer to bubble beds.”Tran.Instn.Chem.Engrs.43.334
Sagert. N.H. and Quinn. M.J.,1978, “The coalescence of gas bubble in dilute aqueous solutions.” Chemical Engineering Science. 33.1087-1102
Wasan. D.T. and Ahluwalia. M.S.,1969, “Consecutive film and surface renewal mechanism for hear or mass transfer from a wall.” Chemical Engineering Science.24.1535-1542
Zana. E. and Leal.L.G,1978, “The dynamics and dissolution of gas bubbles in a viscoelastic fluid.”Int.J.Multiphase Flow. 4. 237-262
Zaidi. A.. Alehyen Z. and Nassim A..,1996, “Contribution to heat transfer in air-lift and bubble column fermentors with Newtonian and non-Newtonian solutions.”Chem.Eng.Comm.155.45-64
107