Two-phase flow structure of bubbly flow in round tube with sudden ezpansion
Experimental studies were made on the multi-dimensional behavior of upward gas-liquid two-phase flow through a vertical pipe with an axisymmetric sudden expansion, which is one of the typical multi-dimensional channel geometries. The aims of this study are to clarify the multi-dimensional behavior of bubbly and slug flow affected by the sudden expansion channel geometry and to accumulate the experimental data for two-phase flow analysis, which is applicable to predict appropriate accuracy the multi-dimensional behavior. In this paper, the first, the observation using high-speed video camera was performed and revealed the multi-dimensional dynamic flow behavior with bubbles and gas-slug affected by the sudden expansion point. From these results, the flow regime map at the below and above of the sudden expansion point were classified with bubble diameter. The second, the variation of the phase distribution in the sudden expansion was measured at the different axial pesitions using a point-electrode resistivity probe for various gas and liquid flow conditions. Thirdly, the cross-sectional averaged void fractions along the flow direction were calculated by using the one-dimensional two-fluid model considering the phase distribution parameter to confirm the applicability of the computations. As a result, they concretely pointed out that some multi-dimensional modeling or modifications for numerical simulation would be needed for more accurate prediction of two-phase flow. Such radial phase distributions in this study are significant for the multi-dimensional two-phase flow analysis.
two-phase flow turbulent bubbly flow sudden ezpansion channel void fraction
Kenji YOSHIDA Koichi KONDO Isao KATOAKA
Department of Mechanical Engineering, Osaka University, Suita, Osaka 565-0871, Japan Department of Marine Engineering, marine Technical College, Ashiya, Hyogo 659-0026, Japan
国际会议
ISSNP2008、CSEPC、ISOFIC2008(第二届21世纪和谐核电系统国际会议、第四届电厂控制中认知系统工程方法国际会议暨第三届未来核电厂仪表与控制国际会议)
哈尔滨
英文
179-185
2008-09-08（万方平台首次上网日期，不代表论文的发表时间）