902 Analysis of Turbulent Structure and Void Fraction Distribution in Boiling Two-Phase Flow with Various Cross Section Tube

2000 ◽  
Vol 2000.75 (0) ◽  
pp. _9-3_-_9-4_
Author(s):  
Masayoshi MUTA ◽  
Saeyun KIM ◽  
Kenji YOSHIDA ◽  
Tomio OKAWA ◽  
Tadayoshi MATSUMOTO ◽  
...  
Keyword(s):  
Cross Section ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Turbulent Structure ◽  
Phase Flow ◽  
Two Phase ◽  
Void Fraction Distribution ◽  
Fraction Distribution

Measurement of Three-Dimensional Time-Averaged Void Fraction Distribution in Rod Bundle in Air-Water System by X-Ray CT Technique

2013 ◽  
Author(s):  
Kenichi Katono ◽  
Jun Nukaga ◽  
Takuji Nagayoshi ◽  
Kenichi Yasuda
Keyword(s):  
Fuel Assembly ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Ct Images ◽  
Phase Flow ◽  
Two Phase ◽  
X Ray ◽  
Void Fraction Distribution ◽  
Fraction Distribution

We have been developing a void fraction distribution measurement technique using the three-dimensional (3D) time-averaged X-ray CT (computed tomography) system to understand two-phase flow behavior inside a fuel assembly for BWR (boiling water reactor) thermal hydraulic conditions of 7.2 MPa and 288 °C. Unlike CT images of a normal standstill object, we can obtain 3D CT images that are reconstructed from time-averaged X-ray projection data of the intermittent two-phase flow. We measured the 3D void fraction distribution in a vertical square (5 × 5) rod array that simulated a BWR fuel assembly in the air-water test. From the 3D time-averaged CT images, we confirmed that the void fraction at the center part of the channel box was higher than that near the channel box wall, and the local void fraction at the central region of a subchannel was higher than that at the gap region of the subchannel. A comparison of the volume-averaged void fractions evaluated by the developed X-ray CT system with those evaluated by a differential pressure transducer in a void fraction range from 0.05 to 0.40 showed satisfactory agreement within a difference of 0.03.

Analysis of Turbulence Structure and Void Fraction Distribution in Gas-Liquid Two-Phase Flow Under Bubbly and Slug Flow Regime

2011 ◽  
Author(s):  
Isao Kataoka ◽  
Kenji Yoshida ◽  
Tsutomu Ikeno ◽  
Tatsuya Sasakawa ◽  
Koichi Kondo
Keyword(s):  
Void Fraction ◽  
Turbulence Model ◽  
Slug Flow ◽  
Two Phase Flow ◽  
Bubbly Flow ◽  
Turbulence Structure ◽  
Phase Flow ◽  
Two Phase ◽  
Void Fraction Distribution ◽  
Fraction Distribution

Accurate analyses of turbulence structure and void fraction distribution are quite important in designing and safety evaluation of various industrial equipments using gas-liquid two-phase flow such as nuclear reactor, etc. Using turbulence model of two-phase flow and models of bubble behaviors in bubble flow and slug flow, systematic analyses of distributions of void fraction, averaged velocity and turbulent velocity were carried out and compared with experimental data. In bubbly flow, diffusion of bubble and lift force are dominant in determining void fraction distribution. On the other hand, in slug flow, large scale turbulence eddies which convey bubbles into the center of flow passage are important in determining void fraction distribution. In turbulence model, one equation turbulence model is used with turbulence generation and turbulence dissipation due to bubbles. Mixing length due to bubble is also modeled. Using these bubble behavior models and turbulence models, systematic predictions were carried out for void distributions and turbulence distributions for wide range of flow conditions of two phase flow including bubbly and slug flow. The results of predictions were compared with experimental data in round straight tube with successful agreement. In particular, concave void distributions in bubbly flow and convex distribution in slug flow were well predicted based on the present model.

0206 Measurement of void fraction distribution around tube in two-phase flow across a horizontal tube bundle

2013 ◽  
Vol 2013 (0) ◽  
pp. _0206-01_-_0206-02_
Author(s):  
Kota MIKAMI ◽  
Hideki MURAKAWA ◽  
Katsumi SUGIMOTO ◽  
Nobuyuki TAKENAKA
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Tube Bundle ◽  
Horizontal Tube ◽  
Phase Flow ◽  
Two Phase ◽  
Void Fraction Distribution ◽  
Fraction Distribution

707 Visualization and Void Fraction Distribution of Gas-Liquid Two-phase Flow in a Vertical Multipath Tube

2006 ◽  
Vol 2006.81 (0) ◽  
pp. _7-7_
Author(s):  
Takenori ITODA ◽  
Hitoshi ASANO ◽  
Katsumi SUGIMOTO ◽  
Nobuyuki TAKENAKA
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Void Fraction Distribution ◽  
Fraction Distribution

scholarly journals Three-Dimensional Void Fraction Distribution of Steady Gas-Liquid Two-Phase Flow by Neutron Radiography

1997 ◽  
Vol 17 (Supplement1) ◽  
pp. 57-58
Author(s):  
Nobuyuki TAKENAKA ◽  
Hitoshi ASANO ◽  
Terushige FUJII ◽  
Masahito MATSUBAYASHI
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Neutron Radiography ◽  
Three Dimensional ◽  
Phase Flow ◽  
Two Phase ◽  
Void Fraction Distribution ◽  
Fraction Distribution
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