雙相流體通過T型管所造成之相分離、分流與壓力分佈的變化是工業上常見的流體現象，在T型管兩端出口不均勻的流體特性可能會造成下游設備不可預期之損壞。在核能工業上，T型管為核子反應器常見的管路結構，對於輕水式反應器(Light-Water Reactor; LWR)發生喪失冷卻水事件(Loss of Coolant Accident; LOCA)時的嚴重事件分析極其重要。本研究補足過去文獻之不足，除各進口條件下之氣水分流率以外，尚提供壓力、空泡分率等重要實驗數據，並配合影像資訊進行分析。
本研究以實驗方法控制進口氣水流量與壓力，探討雙相流體向上流經垂直T型管的相分離現象，並同時建立空泡分率量測與數據分析系統。本實驗之T型管為內徑26 mm之透明壓克力管，垂直向上分流於側邊等尺寸之水平側管，工作流體使用一般過濾水與空氣，本實驗在測試端出口設置氣水分離槽量測分流率；5組電阻感測器，分別安裝在入口處0D、10D、30D與兩出口62D處；進口與兩出口共3只壓力計。本實驗共計完成9組雙相氣泡流進口條件，近100組實驗數據之分析。此外，本研究自行設計一組空泡分率訊號處理系統，以快速截止閥量測法互相校驗，證實阻抗量測法之可行性，獲得垂直管與水平側管量測值 以內之誤差。
本研究建立一套完整的實驗數據庫(Data base)與影相分析，亦提供計算流體力學(Computational Fluid Dynamics; CFD)重要的參數與進口條件設定，有助於CFD雙相流模式的修正與校驗，提升國內核電廠嚴重事故分析之價值。

T-junction is a typical structure in many industrial systems such as power plants, chemical process, and hydrocarbon production industries. The separation of two-phase flow passing through T-junction is a common flow phenomenon. The characteristic of the two-phase flow between the two outlets are always non-uniform, and this kind of fluid status may contribute to the unpredictable damage of downstream facilities.
For the nuclear power plants, severe accidents analysis is important especially for Light-Water Reactors (LWR) when Loss of Coolant Accident (LOCA) occurs. The small break of the pipe may cause the coolant become two-phase flow due to the pressure drop. Under certain conditions, the behavior of T-junction is similar to a gas-liquid separator, as a result of the gas enters the side arm and the liquid flows straight along the run arm. The study aims to establish complete data base for the benchmark of Computational Fluid Dynamics (CFD) model. As a consequence, a vertical T-junction (D=26mm) experimental loop was set up for the purpose of elaborating the complex two-phase fluid phenomena. In this experiment, variables were manipulated under highly controlled conditions and a photographic method was proposed to analyze the images of phase separation. Furthermore, the images obtained by camera have been discussed to receive valuable information about the two phase flow behavior around the T-junction.

誌謝 i
摘要 ii
Abstract iii
目錄 iv
圖目錄 vii
表目錄 xi
符號對照表 xii
第一章 緒論 1
1.1 研究目的與方法 1
1.2 T型管定義及介紹 2
1.3 雙相流譜介紹 3
1.4 T型管中雙相流研究之重要性 5
第二章 文獻回顧 7
2.1 空泡分率定義與量測 7
2.2 T型管實驗回顧 9
第三章 實驗設備與裝置 19
3.1 氣水環路 19
3.1.1 測試端設計 19
3.1.2 Mixing Chamber設計 19
3.1.3 氣水分離槽 20
3.1.4 實驗平台設計與組裝 21
3.2 儀器與量測系統系統介紹 21
3.2.1 流量計及管路設計 21
3.2.2 壓力計 22
3.2.3熱電偶感測器 22
3.2.4數據分析系統 23
3.2.5電阻感測器安裝 23
3.2.6 氣動式球閥控制系統 24
第四章 理論模式分析與討論 38
4.1 理論模式建立 38
4.2 電阻感測器之量測方法 40
第五章 實驗條件與程序 43
5.1實驗條件設定 43
5.2實驗程序 43
第六章 實驗結果與討論 48
6.1電阻感測器驗證結果 48
6.2 T型管氣水分離實驗結果 53
6.3 出口與進口壓差對於分流率之影響 58
6.4 T型相分離對於空泡分率之變化情形 61
第七章 結論 72
參考文獻 73

[1] 徐金城 and 苗志銘, "以實驗量測及數值模擬探討氣液雙相流對於 Y 型微流道燃料電池之效能影響," 2009.
[2] 蕭鈺勳, "中子照相應用於小管徑矩形管之雙相流可視化研究," 清華大學核子工程與科學研究所學位論文, pp. 1-72, 2015.
[3] 馬殷邦, "水平T型歧管中雙相流體分流及壓降之研究," 博士, 核子工程研究所, 國立清華大學, 1990.
[4] M. S. Kazimi and N. E. Todreas, "Nuclear Systems I: Thermal Hydraulics Fundamentals," ed: Hemisphere Publishing Corporation, New York, 1990.
[5] K. McQuillan and P. Whalley, "Flow patterns in vertical two-phase flow," International Journal of Multiphase Flow, vol. 11, no. 2, pp. 161-175, 1985.
[6] A. Mahvash and A. Ross, "Two-phase flow pattern identification using continuous hidden Markov model," International Journal of Multiphase Flow, vol. 34, no. 3, pp. 303-311, 2008.
[7] Z.-K. Gao, N.-D. Jin, and W.-X. Wang, "Definition of Flow Patterns," in Nonlinear Analysis of Gas-Water/Oil-Water Two-Phase Flow in Complex Networks: Springer, 2014, pp. 7-11.
[8] H. K. Kytömaa, "Stability of the structure in multicomponent flows," California Inst. of Tech., Pasadena (USA)1987.
[9] T. J. Honan and R. T. Lahey, "The measurement of phase separation in wyes and tees," Nuclear Engineering and Design, vol. 64, no. 1, pp. 93-102, 1981.
[10] B. t. Azzopardi and P. Whalley, "The effect of flow patterns on two-phase flow in a T junction," International Journal of Multiphase Flow, vol. 8, no. 5, pp. 491-507, 1982.
[11] C. Mak, N. Omebere-Iyari, and B. Azzopardi, "The split of vertical two-phase flow at a small diameter T-junction," Chemical engineering science, vol. 61, no. 19, pp. 6261-6272, 2006.
[12] M. S. Rocha, E. L. Cabral, and J. R. Simões-Moreira, "Capacitance sensor for void fraction measurement in a natural circulation refrigeration circuit," in Proceedings of the International Nuclear Atlantic Conference (INAC’09), 2009.
[13] S. Paranjape, S. N. Ritchey, and S. V. Garimella, "Electrical impedance-based void fraction measurement and flow regime identification in microchannel flows under adiabatic conditions," International Journal of Multiphase Flow, vol. 42, pp. 175-183, 2012.
[14] A. Jaworek, A. Krupa, and M. Trela, "Capacitance sensor for void fraction measurement in water/steam flows," Flow Measurement and Instrumentation, vol. 15, no. 5, pp. 317-324, 2004.
[15] M. d. S. Rocha and J. Simões-Moreira, "Void fraction measurement and signal analysis from multiple-electrode impedance sensors," Heat Transfer Engineering, vol. 29, no. 11, pp. 924-935, 2008.
[16] S. Chakraborty, E. Keller, J. Talley, A. Srivastav, A. Ray, and S. Kim, "Void fraction measurement in two-phase flow processes via symbolic dynamic filtering of ultrasonic signals," Measurement science and technology, vol. 20, no. 2, p. 023001, 2009.
[17] D. U. Lawal, "VOID FRACTION MEASUREMENT USING ELECTRICAL IMPEDANCE TECHNIQUES," International Journal of Advances in Engineering & Technology, vol. 7, no. 5, p. 1539, 2014.
[18] H. Canière et al., "Horizontal two-phase flow characterization for small diameter tubes with a capacitance sensor," Measurement Science and Technology, vol. 18, no. 9, p. 2898, 2007.
[19] M. TSUYAMA, "On the Flow of the Air-Water Mixture in the Branch Pipe: 1. Experiment on the Horizontal Branch Pipe Which is Equal to the Main One in Diameter," Bulletin of JSME, vol. 2, no. 5, pp. 151-156, 1959.
[20] O. Shoham, J. Brill, and Y. Taitel, "Two-phase flow splitting in a tee junction—experiment and modelling," Chemical Engineering Science, vol. 42, no. 11, pp. 2667-2676, 1987.
[21] B. Azzopardi, "Measurements and observations of the split of annular flow at a vertical T-junction," International journal of multiphase flow, vol. 14, no. 6, pp. 701-710, 1988.
[22] M. Davis and B. Fungtamasan, "Two-phase flow through pipe branch junctions," International Journal of Multiphase Flow, vol. 16, no. 5, pp. 799-817, 1990.
[23] G. Das, P. Das, and B. Azzopardi, "The split of stratified gas–liquid flow at a small diameter T-junction," International Journal of Multiphase Flow, vol. 31, no. 4, pp. 514-528, 2005.
[24] A. Elazhary and H. Soliman, "Two-phase flow in a horizontal mini-size impacting T-junction with a rectangular cross-section," International journal of multiphase flow, vol. 42, pp. 104-114, 2012.
[25] M. Mohamed, H. Soliman, and G. Sims, "Conditions for complete phase separation in an impacting tee junction at various inclinations of the outlet arms," International Journal of Multiphase Flow, vol. 47, pp. 66-72, 2012.
[26] E. dos Reis and L. Goldstein, "Fluid dynamics of horizontal air–water slug flows through a dividing T-junction," International Journal of Multiphase Flow, vol. 50, pp. 58-70, 2013.
[27] M. Mohamed, H. Soliman, and G. Sims, "Effects of pipe size and system pressure on the phase redistribution in horizontal impacting tee junctions," Experimental Thermal and Fluid Science, vol. 54, pp. 219-224, 2014.
[28] N. Zheng, L. Zhao, Y. Hwang, J. Zhang, and X. Yang, "Experimental study on two-phase separation performance of impacting T-junction," International Journal of Multiphase Flow, vol. 83, pp. 172-182, 2016.
[29] G. Monrós-Andreu, R. Martínez-Cuenca, S. Torró, and S. Chiva, "Local parameters of air–water two-phase flow at a vertical T-junction," Nuclear Engineering and Design, vol. 312, pp. 303-316, 2017.
[30] M. Mohamed, H. Soliman, and G. Sims, "Experimental investigation of two-phase flow splitting in an equal-sided impacting tee junction with inclined outlets," Experimental Thermal and Fluid Science, vol. 35, no. 6, pp. 1193-1201, 2011.
[31] N. Zuber and J. Findlay, "Average volumetric concentration in two-phase flow systems," Journal of heat transfer, vol. 87, no. 4, pp. 453-468, 1965.
[32] J. Weisman and S. Kang, "Flow pattern transitions in vertical and upwardly inclined lines," International Journal of Multiphase Flow, vol. 7, no. 3, pp. 271-291, 1981.