Chapter 11
Experimental Study of Flow Structure
and Turbulent Characteristics in Lead–
Bismuth Two-Phase Flow
Gen Ariyoshi, Daisuke Ito, and Yasushi Saito
Abstract In a severe accident of a lead–bismuth-cooled accelerator-driven system,
a gas–liquid two-phase flow with a large liquid-to-gas density ratio might appear,
such as a steam leakage into hot lead–bismuth flow. It is still difficult to predict such
phenomena because there are no available flow models for two-phase flow with a
large density ratio compared to ordinary two-phase flows such as an air–water
two-phase flow. Therefore, a two-phase flow model should be developed based on
experimental data of two-phase flows with a large density ratio. In this study, a
liquid–metal two-phase flow was measured by using a four-sensor electrical conductivity probe and a miniature electromagnetic probe to establish an experimental
database for lead–bismuth flow structure. In measurements with the four-sensor
probe, the radial profiles of void fraction and interfacial area concentration were
measured at different axial positions. Experiments were also performed to understand the turbulent structure in a liquid–metal two-phase flow by using the electromagnetic probe. From the data measured by both four-sensor and electromagnetic
probes, it is shown that the turbulence intensity at the pipe center was proportional
to the void fraction to the power of 0.8 for higher void fraction. These results
represented a similar tendency as previous data in air–water two-phase flows.
Keywords Accelerator-driven system • Electromagnetic probe • Four-sensor
probe • Lead–bismuth • Turbulence characteristics • Two-phase flow • Void
fraction
G. Ariyoshi (*)
Graduate School of Energy Science, Kyoto University, Kyoto, Japan
e-mail: ariyoshi.gen.46n@st.kyoto-u.ac.jp
D. Ito • Y. Saito
Kyoto University Research Reactor Institute, Osaka, Japan
© The Author(s) 2015
K. Nakajima (ed.), Nuclear Back-end and Transmutation Technology for Waste
Disposal, DOI 10.1007/978-4-431-55111-9_11
107
Experimental Study of Flow Structure
and Turbulent Characteristics in Lead–
Bismuth Two-Phase Flow
Gen Ariyoshi, Daisuke Ito, and Yasushi Saito
Abstract In a severe accident of a lead–bismuth-cooled accelerator-driven system,
a gas–liquid two-phase flow with a large liquid-to-gas density ratio might appear,
such as a steam leakage into hot lead–bismuth flow. It is still difficult to predict such
phenomena because there are no available flow models for two-phase flow with a
large density ratio compared to ordinary two-phase flows such as an air–water
two-phase flow. Therefore, a two-phase flow model should be developed based on
experimental data of two-phase flows with a large density ratio. In this study, a
liquid–metal two-phase flow was measured by using a four-sensor electrical conductivity probe and a miniature electromagnetic probe to establish an experimental
database for lead–bismuth flow structure. In measurements with the four-sensor
probe, the radial profiles of void fraction and interfacial area concentration were
measured at different axial positions. Experiments were also performed to understand the turbulent structure in a liquid–metal two-phase flow by using the electromagnetic probe. From the data measured by both four-sensor and electromagnetic
probes, it is shown that the turbulence intensity at the pipe center was proportional
to the void fraction to the power of 0.8 for higher void fraction. These results
represented a similar tendency as previous data in air–water two-phase flows.
Keywords Accelerator-driven system • Electromagnetic probe • Four-sensor
probe • Lead–bismuth • Turbulence characteristics • Two-phase flow • Void
fraction
G. Ariyoshi (*)
Graduate School of Energy Science, Kyoto University, Kyoto, Japan
e-mail: ariyoshi.gen.46n@st.kyoto-u.ac.jp
D. Ito • Y. Saito
Kyoto University Research Reactor Institute, Osaka, Japan
© The Author(s) 2015
K. Nakajima (ed.), Nuclear Back-end and Transmutation Technology for Waste
Disposal, DOI 10.1007/978-4-431-55111-9_11
107