流場分析於工業界各領域中相當重要，也是許多實驗與數值模擬的研究對象，而其中常見且重要的管路又以T型管為主。當T型管內的流體為雙相流體時，流體在流經管路分岔處後所產生的相分離現象會導致主管與側管的空泡分率產生變化，此一變化對管路之衝擊與出口壓力差的改變影響甚大，藉由數值模擬的分析，除了可以更加瞭解管道中流體的流動現象並且預測流場趨勢之外，與實驗數據進行分析比對，更可以做為驗證，增加模擬的可靠度及適用性。
用於分析流場的技術很多，本研究室採用計算流體力學(Computational Fluid Dynamics, CFD)的方法計算，並且使用FLUENT進行運算，其先進的數值方法和後處理功能可以較精細的模擬並預測局部的流場情形，以減低流場誤差的發生，這種分析方法目前已經廣泛應用於熱流領域中。
本研究所模擬分析的對象是本研究室自行搭設的垂直T型管路實驗抬架中的流場，T型管截面為圓形，其管徑長度0.026m，主管總長度為1.872m，側管總長度為0.676m。工作流體是空氣與水的雙相混和流體，在沒有溫度差異的條件下由T型管的下方進口，並由主管上方及側管流出，其流型為氣泡流。
本研究在相對應的實驗條件下對該流場進行分析，藉由探討兩側出口壓差及改變不同的雙相流體進口速度、空泡分率等參數，分析在T型管分岔處的流場空泡分率分布、相分離情形、壓力分布、出口壓差變化等，並與實驗結果進行分析比對，最終建立一個可以應用於垂直T型管中且流型為氣泡流的運算模式。

Multiphase flow analysis is an important research topic since it is a common phenomenon in lots of energy related industries. Numerous experiments and numerical analysis had been down by studied about it. Two-phase flow is a flow which consist of gas and liquid and is a particular example of multiphase flow.
There are many kinds of pipelines used in industrial applications for transport two-phase flow. T junction is an significant component of pipeline systems. Few of studies of multiphase flow through T junction have been studied until 1980s, however, a great number of related research has shown up since then.
This paper presents a model of two-phase flow which consist of air and water through T junction. The research will discuss the pressure difference between inlet and outlet and the phenomenon of phase redistribution. The flow pattern of the working fluid is bubbly flow and ANYSY FLUENT is chosen as the simulating software.

[1] Christopher E. Brennen, “Fundamentals of Multiphase Flows”, California Institute of Technology, 2005
[2] 潘欽，沸騰熱傳與雙向流，2001，411-425
[3] T. Anderson, R. Jackson, A fluid mechanical description of fluidized beds, Ind. Eng. Chem. Fundam., 6 (4) (1967), pp. 527-539
[4] S. Garg, J. Pritchett, Dynamics of gas-fluidized beds, J. Appl. Phys., 46 (10) (1975), pp. 4493-4500
[5] Ishii, M ” Thermo-fluid dynamics Theory of two-phase flow,” Eyrolles, Paris, 1975
[6] Dalhaye, J.M., 1981a, “Local Instantaneous Equations,” ch.5, Thermo-hydraulics of Two-phase Systems for Industrial Design and Nuclear Engineering, Ed. Delhyaye, J.M., Gio, M., and Riethmuller, M.L., Hemisphere Publishing Co., Washington.
[7] Dalhaye, J.M., 1981b, “Instantaneous Space-averaged Equations,” ch.7, Thermo-hydraulics of Two-phase Systems for Industrial Design and Nuclear Engineering, “ Ed. Delhyaye, J.M., Gio, M., and Riethmuller, M.L., Hemisphere Publishing Co., Washington.
[8] M. Popp and D.W. Sallet, “Experimental investigation of one- and two-phase flow through a tee-junction”, Physical Modeling of Multiphase Flow, Coventry, England, 1983.
[9] M.R. Davis, B. Fungtamasan, “Two-phase flow through pipe branch junction”, International Journal of Multiphase Flow, 1990, 16(5):799-817.
[10] R.I. Issa, P.J. Oliveria, “Numerical prediction of phase separation in two-phase flow through T-junctions”, Computers & Fluids, 1994, 23(2):347-372.
[11] T. Stacey, B.J. Azzopardi, G. Conte, “The split of annular two-phase flow at a small diameter T-junction”, International journal of multiphase flow, 2000, 26(5):845-856.
[12] G. Das, K. Dasp, B.J. Azzopari, “The split of stratified gas-liquid flow at a small diameter T-junction”, International journal of multiphase flow, 2005, 31(4):514-528.
[13] B.G.M van Wachem, “Methods for multiphase computational fluid dynamics”, Chemical Engineering Journal, 2003,96, 81-98.
[14] A.S Athulya, R. Miji Cherian, “CFD Modeling of Multiphase Flow through T Junction”, International Conference on Emerging Trends in Engineering, Science and Technology, (ICETEST-2015), 2016, 24:325-331
[15] M. Ishii and T. Hibiki, Thermo-fluid dynamics of two-phase flow., Springer Science & Business Media, 2010.
[16] J. Weisman, S.Y. Kang, “Flow pattern transitions in vertical and upwardly inclined lines” International Journal of Multiphase Flow, 1981, 7(3), 271-291.
[17] Jiun-Ren Wang, Chung-Yen Hsu, Yuh-Ming Ferng “The Flow Visualization for the Separation of Air-water Bubbly Two-phase Flow Through a Vertical T-junction” 2017 American Nuclear Society Annual Meeting, San Francisco, CA, USA, June 11-15, 2017