Two-phase flow patterns in a 90° bend at microgravity
- 79 Downloads
Bends are widely used in pipelines carrying single-and two-phase fluids in both ground and space applications. In particular, they play more important role in space applications due to the extreme spatial constraints. In the present study, a set of experimental data of two-phase flow patterns and their transitions in a 90° bend with inner diameter of 12.7 mm and curvature radius of 76.5 mm at microgravity conditions are reported. Gas and liquid superficial velocities are found to range from (1.0≈23.6) m/s for gas and (0.09≈0.5) m/s for liquid, respectively. Three major flow patterns, namely slug, slug-annular transitional, and annular flows, are observed in this study. Focusing on the differences between flow patterns in bends and their counterparts in straight pipes, detailed analyses of their characteristics are made. The transitions between adjoining flow patterns are found to be more or less the same as those in straight pipes, and can be predicted using Weber number models satisfactorily. The reasons for such agreement are carefully examined.
Key Wordstwo-phase flow flow patterns 90° bend microgravity
Unable to display preview. Download preview PDF.
- 2.Colin C, Fabre J, McQuillen J. Bubble and slug flow at microgravity conditions: state of knowledge and open questions.Chem Eng Comm, 1996, 141/142: 155–173Google Scholar
- 3.Hewitt GF. Multiphase flow: the gravity of the situation. In: 3rd Microgravity Fluid Physics Conf, 1996-7-13-15, Cleveland, OH, USA, 1996. 1–30Google Scholar
- 4.Zhao JF. A review of two-phase gas-liquid flow patterns under microgravity conditions.Advances in Mechanics, 1999, 29: 369–382 (in Chinese)Google Scholar
- 5.Gabriel KS. Microgravity two-phase flow and heat transfer: what have we learned? In: 12th Int Heat Pipe Conf, May, 2002, Moscow, RussiaGoogle Scholar
- 6.McQuillen J. Observations of gas-liquid flows through contractions in microgravity. In: Proc 3rd Microgravity Fluid Physics Conf, 1996-7-13-15, Cleveland, OH, USA, 1996, 95–102Google Scholar
- 7.Jayawerdena SS, McQuillen JB. Microgravity two-phase flow at a pipe junction. In: 27th AIAA Fluid Dynamics Conference, 1996-6-17-20, New Orleans, LA, USA, AIAA-96-2070Google Scholar
- 8.Keshock EG, Lin CS. Two-phase annular flow in helical coil flow channels in a reduced gravity environment. In: Proc. 3rd Microgravity Fluid Physics Conf, 1996-7-13-15, Cleveland, OH, USA, 1996. 115–120Google Scholar
- 9.Berg CP, Dreyer ME, Rath HJ. Two-phase flow in 90° bends in microgravity. In: Drop Tower Days 2002, 2002-11-26-29, Tokyo & Sapporo, JapanGoogle Scholar
- 11.Gardner GC, Neller PH. Phase distributions in flow of an air-water mixture round bends and past obstructions at the wall of a 76-mm bore tube.Proc Inst Mech Eng, 1969–70, 184(3C): 93–101Google Scholar