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完整後設資料紀錄
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.advisor | 李雨(U Lei) | |
dc.contributor.author | Hshing-I Yeh | en |
dc.contributor.author | 葉星毅 | zh_TW |
dc.date.accessioned | 2021-06-16T05:37:50Z | - |
dc.date.available | 2016-08-21 | |
dc.date.copyright | 2014-08-21 | |
dc.date.issued | 2014 | |
dc.date.submitted | 2014-08-12 | |
dc.identifier.citation | [1] Batchelor, G. K., “The effect of Brownian motion on the bulk stress in the suspension of spherical particles,” J. Fluid Mech., 83, 97-117 (1977).
[2] Munson, B. R., Young, D. F. and Okiishi, T. H., “Fundamentals of fluid mechanics,” 2nd edition, John Wiley & Sons (1994) [3] Choi, U.S., “Enhancing thermal conductivity of fluids with nanoparticles.” Developments and Applications of non-Newtonian Flows, D. A. Siginer and H. P. Wang, eds., FED-vol. 231/MD-Vol. 66, ASME, New York, 99-105 (1995). [4] Choi, S. U. S., Zhang, Z. G., Yu, W., Lockwood, F. E. and Grulke, E. A., “Anomalous thermal conductivity enhancement in nano-tube suspensions,” Appl. Phys. Lett., 79, 2252–2254 (2001). [5] Haynes, W. H., “CRC Handbook of Chemistry & Physics,” 94th Edition, CRCnetBASE (2013). [6] Eastman, J. A., Choi, S. U. S., Li, S., Yu, W. and Thompson, L. J., “Anomalously increased effective thermal conductivities of ethylene glycol based nanofluids containing copper nanoparticles,” Appl. Phys. Lett., 78(6), 718–720, (2001). [7] Einstein A., “Eine neue bestimmung der molekuldimensionen,” Ann. Phys. 19 289-306 (1906). [8] Gupta, S. M. and Tripathi, M., “A review of TiO2 nanoparticles.” Chin. Sci. Bull., 56, 1639– 1657 (2011). [9] Jiang, J., Oberdorster, G. and Biswas, P., “Characterization of size, surface charge, and agglomeration state of nanoparticle dispersions for toxicological studies,” J. Nanopart. Res., 11, 77–89 (2009). [10] Sarojini, K. G. K., Nanoj, S. V., Singh, P. K., Pradeep, T. and Das, S. K., “Electrical conductivity of ceramic and metallic nanofluids,” Colloids Surfaces A:Physicochem. Eng. Aspects, 417, 39-46 (2013). [11] Maxwell J. C., “A treatise on electricity and magnetism,” Clarendon, Oxford, UK, (1873). [12] Murshed, S., Leong, K. and Yang, C.,“Thermophysical and Electrokinetic properties of nanofluids – A critical review,” Applied Thermal Engineering, 28, 2109-2125 (2008). [13] Rashin, M. N. and J. Hemalatha, J., “Viscosity studies on novel copper oxide –coconut oil nanofluid,” Exp. Therm. Fluid Sci., 48, 67–72, (2013). [14] Masoumi., N., Sohrabi, N. and Behzadmehr, A., “A new model for calculating the effective viscosity of nanofluids,” J. Phys. D: Appl. Phys. 42(5) 055501 (2009). [15] Pak, B. and Cho, Y., “Hydrodynamic and heat transfer study of dispersed fluid with submicron metallic oxide particles,” Experimental Heat Transfer, 11, 151-170 (1998). [16] Prasher, R., Song, D., Wang, J. and Phelan, P.E., “Measurements of nanofluid viscosity and its implications for thermal applications,” Applied Physics Letters, 89 133108 (2006). [17] Ganguly, S., Sikdar, S. and Basu, S., “Experimental investigation of the effective electrical conductivity of aluminium oxide nanofluids,” Powder Technol., 196, 326–330 (2009). [18] Wamkam C. T, Opoku, M. K., Hong, H. and Smith P., “Effects of pH on heat transfer nanofluids containing ZrO2 and TiO2 nanoparticles,” J Appl. Phys. 109, 024305 (2011). [19] Lu, W. and Fan, Q., “Study for the particle’s scale effect on some thermophysical properties of nanofluids by a simplified molecular dynamics method,” Eng. Anal. Boundary Elem. 32(4), 282–289, (2008). [20] Xue, Q. Z., ‘‘Model for effective thermal conductivity of nanofluids,’’ Physics Letters A, 307, 313–317 (2003). [21] He, Y., Jin, Y., Chen, H, Ding, Y., Cang, D. and Lu, H., “Heat transfer and flow behavior of aqueous suspensions of TiO2 nanoparticles (nanofluids) flowing upward through a vertical pipe,” Int. J. Heat Mass Transfer, 50, 2272–2281 (2007). [22] 陳妍名, “微流道內奈米流體強制熱對流之實驗研究,” 國立臺灣大學碩士論文 (2013)。 [23] “大學普通化學實驗”,第十二版,國立臺灣大學出版中心。 [24] 蔡宗翰, “Investigation of thermal properties of nanofluids and the application of ferrofluids on transformers,” Ph.D dissertation, National Taiwan University (2010). | |
dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/56613 | - |
dc.description.abstract | 奈米流體為具均勻分散及穩定懸浮奈米粒子的懸浮液。據文獻報告其熱傳導係數明顯高於其基底液體者及傳統理論預測值,但其機制並未完全明瞭。此現象可望應用在熱交換器上,而其中泵之輸出功率由冷卻液的黏度主導。因此奈米流體的黏度亦為相關研究的重點、且為本文之研究目標。本文以二氧化鈦奈米粒子加入水或甘油等基底流體中來合成奈米流體,對其進行黏度的實驗研究,共獲致如下結果:(i)在所探討的參數範圍內,奈米流體是牛頓流體。(ii)黏度隨著粒子體積濃度的增加而上升、隨著粒子粒徑的下降而上升、及隨著溫度的增加而下降;但相對黏度(奈米流體黏度與基底液體黏度的比值)卻不隨溫度的改變而改變,顯示奈米流體與基底液體隨溫度的改變定性相同,但在定量上粒子粒徑愈小、且基底液體愈不黏者,因布朗效應愈強故其相對黏度愈大;另體積濃度愈高,愈多粒子參予布朗效應,而使相對黏度也愈高。(iii)奈米流體黏度會隨基底液體的導電率增加而上升,至其pH值達等電位點(約pH = 6)時,黏度達到峰值、而約為基底液體黏度的240倍,pH值超過等電位點後,黏度會迅速下降。上述現象可用因電雙層效應引致的粒子間庫倫斥力弱化或消失、而導致粒子迅速聚集來作解釋。(iv) 黏度隨放置時間之增加而略降,此一老化效應在較高體積濃度時才比較明顯,如體積濃度為4%時,放置一週後其黏度約下降10%。 | zh_TW |
dc.description.abstract | Nanofluid is a liquid suspended with uniformly distributed and stable nano-sized particles. The heat conductivity of nanofluid is substantially higher than that of its base fluid and the classical theoretical prediction according to the literature, but the mechanisms are still not fully understood. Such a heat conductivity enhancement implies that nanofluids can be applied to heat exchangers. However, the pumping power of nanofluids in heat exchanger depends on its viscosity, which is also one of the major topics of nanofluid research, and is also the goal of the present thesis. The nanofluids of the present study are made by introducing TiO2 nano particles into de-ionized water or glycerol. Viscosity measurements were performed and the results are summarized as follows: (i) Nanofluids are Newtonian fluids in the parameter ranges of the present study. (ii) The viscosity of nanofluid increases as the particle’s volume fraction increases, as the particle size decreases, and as the temperature decreases. On the other hand, the relative viscosity (the ratio between the nanofluid viscosity and the base fluid viscosity) remains essentially invariant with temperature, implying that the temperature variation of nanofluid viscosity is qualitatively similar to that of base fluid. However, the relative viscosity of nanofluid is larger for case with smaller particles and with less viscous base fluid, because of the stronger Brownian effect. Also the relative viscosity is larger for higher volume fraction as more particles participates the Brownain effect. (iii) The nanofluid viscosity increases with the base fluid electric conductivity, and reaches its maximum value (about 240 times the viscosity of the base fluid) at an electric conductivity corresponds to the isoelectric point (when pH = 6 approximately). The viscosity decreases rapidly as the pH value increases further above the isoelectric point. The above phenomena can be explained by the particle agglomeration effect associated with the weakening of the Coulomb’s repulsive force between electric double layers of two particles. (iv) The viscosity decreases slightly as times goes by. Such an aging effect becomes moderate at higher volume fraction. For example, the viscosity decreases about 10% after a week for a nanofluid with volume fraction 4%. | en |
dc.description.provenance | Made available in DSpace on 2021-06-16T05:37:50Z (GMT). No. of bitstreams: 1 ntu-103-R01543072-1.pdf: 1630945 bytes, checksum: d8c53e4968f177a561fa2fb0ae05029e (MD5) Previous issue date: 2014 | en |
dc.description.tableofcontents | 致謝 II
摘要 III Abstract IV 第一章 緒論 1 1-1 研究背景 1 1-2研究目的與動機 2 1-3文獻回顧 2 1-4文本架構 4 第二章 原理 5 2-1 黏度計測量原理 5 2-2 導電率計之測量原理 7 2-3 pH值計之測量原理 8 2-4 懸浮液的黏度 8 2-5 電雙層 9 2-6等效顆粒 11 第三章 研究方法與實驗步驟 13 3-1奈米流體的調配 13 3-2 改變基底流體之導電率 14 3-3 改變基底流體之pH值 15 3-4流體性質量測之實驗步驟 16 3-4-1 奈米流體之流變性質 17 3-4-2 體積分率、顆粒大小以及溫度的影響 17 3-4-3改變基底流體導電率之奈米流體黏度與導電率測量 18 3-4-4改變基底流體pH質之奈米流體黏度與導電率測量 19 3-4-5老化效應(Aging effect) 19 第四章 研究結果與討論 20 4-1 以去離子水為基底之奈米流體之流變性質 20 4-2 以去離子水為基底之奈米流體之體積分率、顆粒大小及溫度對黏度及導電率的影響 20 4-3以甘油為基底流體之奈米流體之流變性質與體積分率、顆粒大小以及溫度對黏度的影響 21 4-4改變基底流體導電率與酸鹼度之奈米流體黏度與導電率測量 22 4-4 老化效應(Aging effect) 24 第五章 結論及未來展望 25 5-1 結論 25 5-2 未來展望 26 參考書目 27 | |
dc.language.iso | zh-TW | |
dc.title | 二氧化鈦奈米流體黏滯性質的實驗探討 | zh_TW |
dc.title | Experimental Study of Viscosity of Titanium Oxide Nanofluids | en |
dc.type | Thesis | |
dc.date.schoolyear | 102-2 | |
dc.description.degree | 碩士 | |
dc.contributor.oralexamcommittee | 田華忠(HWA-CHONG TIEN),楊政穎(C. Y. Yang) | |
dc.subject.keyword | 二氧化鈦,奈米流體,黏度,導電率,布朗運動,電雙層, | zh_TW |
dc.subject.keyword | TiO2,nanofluids,viscosity,electrical conductivity,Brownian motion,Electrical double layer, | en |
dc.relation.page | 52 | |
dc.rights.note | 有償授權 | |
dc.date.accepted | 2014-08-12 | |
dc.contributor.author-college | 工學院 | zh_TW |
dc.contributor.author-dept | 應用力學研究所 | zh_TW |
顯示於系所單位: | 應用力學研究所 |
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