本研究使用溫度敏感磁性流體隨加熱改變磁化強度的特性，並建構一個只需依靠熱能和磁場即可運作的磁熱泵浦。而本研究成功將磁熱泵浦輔以一個針筒式幫浦，在流道高度為400 μm、主流道寬度2 mm、側流道寬度1 mm的T型接面流道生成氣-液與液-液兩相區段流，並使用CCD相機拍攝影像後進行影像處理對兩相區段流的流動模式進行分析。
實驗一開始，會先進行磁流體單相流的閉循環流率量測，以確保兩相區段流實驗時磁熱泵浦施加的壓力是固定的。此外，由於磁流體必須回收以供磁熱泵浦持續運作，因此會在下游緩衝區放置分離磁鐵將磁流體和分散相流體進行分離。然而，分離磁鐵的位置會影響兩相區段流流形。經過不同分離磁鐵位置於氣-液兩相區段流裝置中之測試，發現分離磁鐵位置會影響到氣泡長度，而且靠近流體出入口者皆會阻擋磁流體流動。因此最後決定將分離磁鐵放置於離出入口最遠的位置，並以此設定進行接下來的兩相區段流實驗。
氣-液與液-液兩相區段流分別使用空氣和水作為分散相，磁流體作為連續相進行實驗。在固定磁熱泵浦輸入功率的條件下，發現不論是氣-液或是液-液兩相區段流，分散相長度皆與兩相流率比呈高度正相關，液段長度則與兩相流率比之關係接近反比，並可以此擬合出關係式。氣泡長度隨兩相流率比從1.75個流道寬度上升至3.28個流道寬度。液滴長度則隨兩相流率比從1.47個流道寬度上升至1.79個流道寬度。而液段長度在氣-液兩相區段流隨兩相流率比從6.18下降至1.68個流道寬度，而在液-液兩相區段流隨兩相流率比從18.67下降至6.43個流道寬度。其中液-液兩相區段流由於分散相是水，較高的黏滯度會造成嚴重的阻擋效應，因此液滴長度對兩相流率比之改變較氣泡敏感。此外氣-液和液-液兩相區段流兩者在流形上的表現大致上相似，只有分散相速度的趨勢是反向的。氣-液兩相區段流的分散相雷諾數從0.67提升至1.07；而液-液兩相區段流之分散相雷諾數則從0.81降低為0.53。此現象可歸因為水的阻擋效應較強。
由於磁熱泵浦有推動力的極限，有推不動的風險，因此本研究進行兩相區段流壓降的分析。不論是氣-液或是液-液兩相區段流，兩者的壓降皆會隨兩相流率比上升而上升。造成此現象最主要的原因為界面數量變多，造成界面總壓降上升，進而使壓降上升。

In the present study, a thermomagnetic pump operated by temperature difference and magnetic field was fabricated with temperature-sensitive magnetic fluid (TSMF). The thermomagnetic pump was integrated with a syringe pump and a T-junction flow channel to generate gas-liquid and liquid-liquid two-phase segmented flow. The main channel of the T-junction flow channel was 400 μm high and 2 mm wide. The side channel of the T-junction was 1 mm wide. A CCD camera and the acquired images were used to analyze the flow pattern of the two-phase segmented flow.
Before the experiment started, the closed-loop flow rate measurement with TSMF only was conducted to ensure the pressure provided by the thermomagnetic pump was controlled as constant. An additional magnet was positioned at the buffer zone to separate the two-phase segmented flow and recycle the TSMF. It has been observed that the location of the separation magnet could change the flow pattern. The gas-liquid two-phase segmented flow experiment was investigated first with varying the magnet location, and the influence of the separation magnet to the gas bubble length was determined. As a result, the separation magnet was positioned the most far away from the exit.
The gas-liquid and liquid-liquid two-phase segmented flow experiments were implemented with air and water as the dispersed phases and TSMF as the continuous phase. It has been observed that the dispersed phase lengths were highly correlated to the ratio of the two-phase flow rate in both the gas-liquid and liquid-liquid segmented flow. On the contrary, the length of the continuous phase was highly correlated to the reciprocal of the flow rate ratio of the two-phase segmented flow. Linear equations could be used to fit with the above correlations. The bubble length increased from 1.75 to 3.28 channel width with two-phase flow rate ratio; and the droplet length increased from 1.45 to 1.79 channel width with two-phase flow rate ratio. The gas-liquid slug length decreased from 6.18 to 1.68 channel width with two-phase flow rate ratio; and the liquid-liquid slug length decreased from 18.67 to 6.43 channel width with two-phase flow rate ratio. The slopes of the linear equations in liquid-liquid segmented flow were larger than that of the gas-liquid segmented flow. The reason was that the blockage effect of water was more significant than air because of the high viscosity of water. The gas bubble velocity increased as the two-phase flow rate ratio increased. On the contrary, the liquid droplet velocity decreased with the two-phase flow rate ratio. The Reynolds number estimated with dispersed phase was increased from 0.67 to 1.07 in gas-liquid segmented flow and was decreased from 0.81 to 0.53 in liquid-liquid segmented flow. The reason could also be attributed to the high viscosity of water.
The pressure between the channel inlet and exit has also been investigated. The pressure drop increased with the increasing of flow rate ratio in the segmented flow. The reason was that the increment of interface number in the flow channel would increase the interfacial pressure drop.

摘要 II
Abstract IV
誌謝 VII
圖目錄 XII
表目錄 XVII
符號說明 XVIII
第1章、 緒論 1
1.1 研究動機 1
1.2 文獻回顧 2
1.2.1 溫度敏感磁性流體 2
1.2.2 磁熱泵浦應用 6
1.2.3 兩相區段流(two-phase segmented flow) 17
1.3 研究目的 31
1.4 研究架構 32
第2章、 實驗原理 33
2.1 溫度敏感磁性流體性質 33
2.2 磁熱泵浦原理 36
2.3 兩相區段流分析原理 37
2.4 單相流理論壓降分析原理 40
第3章、 實驗方法 41
3.1 兩相區段流裝置架設 41
3.1.1 氣-液兩相區段流裝置 41
3.1.2 液-液兩相區段流裝置 43
3.2 磁熱泵浦製作 46
3.3 流道製作 47
3.3.1 矽晶圓流道母模製作 48
3.3.2 熱壓印壓克力流道製作 51
3.3.3 壓克力流道黏合 52
3.4 兩相區段流影像分析方法 54
第4章、 溫度敏感磁性流體搭配空氣或水形成兩相區段流流動分析 59
4.1 磁熱泵浦流率校正 59
4.2 兩相區段流生成過程觀察 62
4.3 兩相區段流性質探討 65
4.3.1 不同分離磁鐵位置下兩相區段流性質探討 66
4.3.2 氣-液兩相區段流流形探討 71
4.3.3 液-液兩相區段流流形探討 77
4.3.4 兩相區段流壓降量測結果 83
第5章、 結論與未來工作 86
5.1 結論 86
5.2 未來工作 88
參考文獻 90
附錄 94
A. Shearing regime 液滴生成模式 94

[1] M. R. McDevitt and D. L. Hitt, "Liquid phase hydrogen peroxide decomposition for micro-propulsion applications," Advances in aircraft and spacecraft science, vol. 4, no. 1, p. 21, 2017.
[2] P. Phong, P. Nam, D. Manh, and I.-J. Lee, "Mn0. 5Zn0. 5Fe2O4 nanoparticles with high intrinsic loss power for hyperthermia therapy," Journal of Magnetism and Magnetic Materials, vol. 433, pp. 76-83, 2017.
[3] R. E. Rosensweig, Ferrohydrodynamics. Courier Corporation, 2013.
[4] R. Arulmurugan, B. Jeyadevan, G. Vaidyanathan, and S. Sendhilnathan, "Effect of zinc substitution on Co–Zn and Mn–Zn ferrite nanoparticles prepared by co-precipitation," Journal of Magnetism and Magnetic Materials, vol. 288, pp. 470-477, 2005.
[5] R. Hao, H. Liu, F. Xing, and J. Ma, "Study on developing application fields of micro differential pressure sensor with magnetic fluid," in Journal of Physics: Conference Series, 2020, vol. 1550, no. 4: IOP Publishing, p. 042010.
[6] E. Resler Jr and R. Rosensweig, "Magnetocaloric power," AIAA Journal, vol. 2, no. 8, pp. 1418-1422, 1964.
[7] H. Matsuki, K. Yamasawa, and K. Murakami, "Experimental considerations on a new automatic cooling device using temperature-sensitive magnetic fluid," IEEE Transactions on Magnetics, vol. 13, no. 5, pp. 1143-1145, 1977.
[8] K. Fumoto, H. Yamagishi, and M. Ikegawa, "A mini heat transport device based on thermo-sensitive magnetic fluid," Nanoscale and Microscale Thermophysical Engineering, vol. 11, no. 1-2, pp. 201-210, 2007.
[9] W. Lian, Y. Xuan, and Q. Li, "Characterization of miniature automatic energy transport devices based on the thermomagnetic effect," Energy Conversion and Management, vol. 50, no. 1, pp. 35-42, 2009.
[10] Y. Iwamoto, H. Nakasumi, Y. Ido, and H. Yamaguchi, "Long-distance heat transport based on temperature-dependent magnetization of magnetic fluids," International Journal of Applied Electromagnetics and Mechanics, vol. 62, no. 4, pp. 711-724, 2020.
[11] 楊智鈞, "溫度敏感磁性流體在磁熱泵浦的應用與量測," 碩士, 動力機械工程學系, 國立清華大學, 新竹市, 2020. [Online]. Available: https://hdl.handle.net/11296/wnm46m
[12] 李彥均, "溫度敏感磁性流體於串聯磁熱泵浦的應用與性能分析," 碩士, 動力機械工程學系, 國立清華大學, 2020. [Online]. Available: http://thesis.lib.nccu.edu.tw/record/#G021080335010%22.
[13] H. Yamaguchi and Y. Iwamoto, "Energy transport in cooling device by magnetic fluid," Journal of Magnetism and Magnetic Materials, vol. 431, pp. 229-236, 2017.
[14] G. Taylor, "Deposition of a viscous fluid on the wall of a tube," Journal of fluid mechanics, vol. 10, no. 2, pp. 161-165, 1961.
[15] M. T. Kreutzer, F. Kapteijn, J. A. Moulijn, and J. J. Heiszwolf, "Multiphase monolith reactors: chemical reaction engineering of segmented flow in microchannels," Chemical Engineering Science, vol. 60, no. 22, pp. 5895-5916, 2005.
[16] V. van Steijn, C. R. Kleijn, and M. T. Kreutzer, "Flows around confined bubbles and their importance in triggering pinch-off," Physical review letters, vol. 103, no. 21, p. 214501, 2009.
[17] V. van Steijn, C. R. Kleijn, and M. T. Kreutzer, "Predictive model for the size of bubbles and droplets created in microfluidic T-junctions," Lab on a Chip, vol. 10, no. 19, pp. 2513-2518, 2010.
[18] V. van Steijn, M. T. Kreutzer, and C. R. Kleijn, "μ-PIV study of the formation of segmented flow in microfluidic T-junctions," Chemical Engineering Science, vol. 62, no. 24, pp. 7505-7514, 2007.
[19] P. PARTHIBAN, "Multiscale Dynamics of Bubbles and Droplets in Microfluidic Networks," 2012.
[20] 黃柏翰, "溫度螢光感測技術與粒子影像速度量測技術應用於兩相區段流熱傳分析," 碩士, 動力機械工程學系, 國立清華大學, 2013. [Online]. Available: http://thesis.lib.nccu.edu.tw/record/#GH02100033511%22.
[21] I. Kobayashi and M. Nakajima, "Generation and multiphase flow of emulsions in microchannels," p. 154, 2006.
[22] M. N. Kashid and D. W. Agar, "Hydrodynamics of liquid–liquid slug flow capillary microreactor: flow regimes, slug size and pressure drop," Chemical Engineering Journal, vol. 131, no. 1-3, pp. 1-13, 2007.
[23] J. Jovanović, W. Zhou, E. V. Rebrov, T. Nijhuis, V. Hessel, and J. C. Schouten, "Liquid–liquid slug flow: hydrodynamics and pressure drop," Chemical Engineering Science, vol. 66, no. 1, pp. 42-54, 2011.
[24] J. Yue, E. V. Rebrov, and J. C. Schouten, "Gas–liquid–liquid three-phase flow pattern and pressure drop in a microfluidic chip: similarities with gas–liquid/liquid–liquid flows," Lab on a Chip, vol. 14, no. 9, pp. 1632-1649, 2014.
[25] M. M. G. Eain, V. Egan, J. Howard, P. Walsh, E. Walsh, and J. Punch, "Review and extension of pressure drop models applied to Taylor flow regimes," International Journal of Multiphase Flow, vol. 68, pp. 1-9, 2015.
[26] A. Ładosz and P. R. von Rohr, "Pressure drop of two-phase liquid-liquid slug flow in square microchannels," Chemical Engineering Science, vol. 191, pp. 398-409, 2018.
[27] S. Garimella, J. Killion, and J. Coleman, "An experimentally validated model for two-phase pressure drop in the intermittent flow regime for circular microchannels," J. Fluids Eng., vol. 124, no. 1, pp. 205-214, 2002.
[28] K. Zhang, Q. Liang, X. Ai, P. Hu, Y. Wang, and G. Luo, "On-demand microfluidic droplet manipulation using hydrophobic ferrofluid as a continuous-phase," Lab on a Chip, vol. 11, no. 7, pp. 1271-1275, 2011.
[29] N. G. J. Gui, "Heat Transfer Enhancement in Microchannels using Magnetic Two-Phase Liquid-Liquid Plug Flow," RMIT University, 2019.
[30] R. K. Shah and S. Khandekar, "Manipulation of Taylor bubble flow in a magneto-fluidic system," Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol. 593, p. 124589, 2020.
[31] H. Zhou, Y. Yao, Q. Chen, G. Li, and S. Yao, "A facile microfluidic strategy for measuring interfacial tension," Applied Physics Letters, vol. 103, no. 23, p. 234102, 2013.
[32] M. Bahrami, M. Yovanovich, and J. Culham, "Pressure drop of fully-developed, laminar flow in microchannels of arbitrary cross-section," in International Conference on Nanochannels, Microchannels, and Minichannels, 2005, vol. 41855, pp. 269-280.
[33] N. A. Mortensen, F. Okkels, and H. Bruus, "Reexamination of Hagen-Poiseuille flow: Shape dependence of the hydraulic resistance in microchannels," Physical Review E, vol. 71, no. 5, p. 057301, 2005.
[34] V. Van Steijn, M. Kreutzer, and C. Kleijn, "Velocity fluctuations of segmented flow in microchannels," Chemical Engineering Journal, vol. 135, pp. S159-S165, 2008.
[35] Microchem, "SU-8 2000 Permanent Epoxy Negative Photoresist PROCESSING GUIDELINES FOR: SU-8 2100 and SU-8 2150," 2005.
[36] W. W. Y. Chow, K. F. Lei, G. Shi, W. J. Li, and Q. Huang, "Microfluidic channel fabrication by PDMS-interface bonding," Smart materials and structures, vol. 15, no. 1, p. S112, 2005.
[37] R. Kurimoto, K. Nakazawa, H. Minagawa, and T. Yasuda, "Prediction models of void fraction and pressure drop for gas-liquid slug flow in microchannels," Experimental Thermal and Fluid Science, vol. 88, pp. 124-133, 2017.
[38] R. Rosensweig, R. Kaiser, and G. Miskolczy, "Viscosity of magnetic fluid in a magnetic field," Journal of Colloid and Interface Science, vol. 29, no. 4, pp. 680-686, 1969.
[39] T. Abadie, J. Aubin, D. Legendre, and C. Xuereb, "Hydrodynamics of gas–liquid Taylor flow in rectangular microchannels," Microfluidics and nanofluidics, vol. 12, no. 1, pp. 355-369, 2012.
[40] M. Mei, F. Felis, G. Hebrard, N. Dietrich, and K. Loubière, "Hydrodynamics of gas–liquid slug flows in a long in-plane spiral shaped milli-reactor," Theoretical Foundations of Chemical Engineering, vol. 54, no. 1, pp. 25-47, 2020.