Real-Time Cross-Sectional Averaged Void Fraction Measurements in Vertical Annulus Gas-Liquid Two-Phase Flow by Neutron Radiography and X-ray Tomography Techniques

1995 ◽  
pp. 781-792 ◽  
Author(s):  
G.D. Harvel ◽  
K. Hori ◽  
K. Kawanishi ◽  
J.S. Chang
Keyword(s):  
Real Time ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Neutron Radiography ◽  
Phase Flow ◽  
Two Phase ◽  
Cross Sectional ◽  
X Ray ◽  
Vertical Annulus

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.

Research on Measurement of Void Fraction for Vertically Rising Pipes by Optical Fiber Probe

2011 ◽  
Vol 361-363 ◽  
pp. 671-675 ◽  
Author(s):  
Feng Yun Chen ◽  
Wei Min Liu
Keyword(s):  
Optical Fiber ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Exponential Model ◽  
Phase Flow ◽  
Two Phase ◽  
Cross Sectional ◽  
Fiber Probe ◽  
Optical Fiber Probe ◽  
Oil Gas

A way of measuring the average cross-sectional void fraction for vertically rising oil pipes by using closing valves quickly and optical fiber probe has been researched. Experiments were performed in oil-gas two-phase flow and the range of the average void fraction is 0.1～0.5. The relationship between average cross-sectional void fraction of a oil-gas two-phase flow and pipe’s center void fraction in vertically rising oil pipes, for different pipe diameters and varying oil flow, is obtained. An exponential model of average void fraction is also obtained with reference to Bankoff’s[1] variable density model. It is found that local void fraction reduces from center in radial direction and the local void fraction maximum value appears in the pipe’s center.

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