Prediction of Countercurrent Flow Limitation and Its Uncertainty in Horizontal and Slightly Inclined Pipes

2017 ◽  
Vol 197 (2) ◽  
pp. 140-157 ◽  
Author(s):  
Michio Murase ◽  
Yoichi Utanohara ◽  
Takayoshi Kusunoki ◽  
Yasunori Yamamoto ◽  
Dirk Lucas ◽  
...  
Keyword(s):  
Countercurrent Flow ◽  
Flow Limitation ◽  
Inclined Pipes

Countercurrent Flow Limitation in Slightly Inclined Pipes With Elbows

2015 ◽  
Vol 1 (4) ◽  
Author(s):  
Michio Murase ◽  
Ikuo Kinoshita ◽  
Takayoshi Kusunoki ◽  
Dirk Lucas ◽  
Akio Tomiyama
Keyword(s):  
Friction Coefficient ◽  
Single Phase ◽  
Wall Friction ◽  
Scale Model ◽  
Gas Flows ◽  
Countercurrent Flow ◽  
Flow Limitation ◽  
Adjustment Factor ◽  
Pressurized Water ◽  
Inclined Pipes

One-dimensional (1D) sensitivity computations were carried out for air–water countercurrent flows in a 1/15-scale model of the hot leg and a 1/10-scale model of the pressurizer surge line in a pressurized water reactor (PWR) to generalize the prediction method for countercurrent flow limitation (CCFL) characteristics in slightly inclined pipes with elbows. In the 1D model, the wall friction coefficient fwG of single-phase gas flows was used. The interfacial drag coefficient of fi=0.03, an appropriate adjustment factor of NwL=6 for the wall friction coefficient fwL of single-phase liquid flows (NwG=1 for fwG of single-phase gas flows), and an appropriate adjustment factor of Nde=6 for the pressure loss coefficient ζe of elbows in single-phase flows were determined to give good agreement between the computed and measured CCFL characteristics. The adjusted factors were used to compute and then discuss effects of the inclination angle and diameter on CCFL characteristics.

ICONE23-1182 EFFECTS OF INCLINATION ANGLES ON COUNTERCURRENT FLOW LIMITATION IN SLIGHTLY INCLINED PIPES

2015 ◽  
Vol 2015.23 (0) ◽  
pp. _ICONE23-1-_ICONE23-1 ◽  
Author(s):  
Michio Murase ◽  
Yoichi Utanohara ◽  
Takayoshi Kusunoki ◽  
Dirk Lucas ◽  
Akio Tomiyama
Keyword(s):  
Countercurrent Flow ◽  
Flow Limitation ◽  
Inclination Angles ◽  
Inclined Pipes

Countercurrent flow limitation in inclined channels with bends

1994 ◽  
Vol 152 (1-3) ◽  
pp. 379-388 ◽  
Author(s):  
S.M. Ghiaasiaan ◽  
R.E. Turk ◽  
S.I. Abdel-Khalik
Keyword(s):  
Countercurrent Flow ◽  
Flow Limitation ◽  
Inclined Channels

scholarly journals Effects of Diameters on Countercurrent Flow Limitation at a Square Top End in Vertical Pipes

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Michio Murase ◽  
Koji Nishida ◽  
Toshihide Torige ◽  
Toshiya Takaki ◽  
Raito Goda ◽  
...  
Keyword(s):  
Water Level ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Strong Relationship ◽  
Countercurrent Flow ◽  
Flow Limitation ◽  
Vertical Pipe ◽  
Surge Line ◽  
Inclined Pipe

The falling liquid flow rate under flooding conditions is limited at a square top end of a vertical pipe in the pressurizer surge line with the diameter of about 300 mm that consists of a vertical pipe, a vertical elbow, and a slightly inclined pipe with elbows. In this study, therefore, we evaluated effects of diameters on countercurrent flow limitation (CCFL) at the square top end in vertical pipes by using existing air-water data in the diameter range of D = 19-250 mm. As a result, we found that there was a strong relationship between the constant CK and the slope m in the Wallis-type correlation where the Kutateladze parameters were used for the dimensionless gas and liquid velocities. The constant CK and the slope m increased when the water level is increased in the upper tank h. CCFL at the square top end of the vertical pipes could be expressed by the Kutateladze parameters with CK = 1.53±0.11 and m = 0.97 for D ≥ 30 mm. The CK values were smaller for D = 19-25 mm than those for D ≥ 30 mm.

Countercurrent flow limitation at a square top end of vertical pipes and in a pressurizer surge line

2020 ◽  
Vol 363 ◽  
pp. 110624
Author(s):  
Toshiya Takaki ◽  
Michio Murase ◽  
Koji Nishida ◽  
Toshihide Torige ◽  
Akio Tomiyama
Keyword(s):  
Countercurrent Flow ◽  
Flow Limitation ◽  
Surge Line

A Proposed Calculational Model for Two-Phase Countercurrent Flow Limitation in Channels with Abrupt Area Change

1990 ◽  
Vol 89 (2) ◽  
pp. 227-232
Author(s):  
Tanvir Salim ◽  
Woon-Shing Yeung ◽  
R. Thomas Fernandez
Keyword(s):  
Countercurrent Flow ◽  
Flow Limitation ◽  
Two Phase ◽  
Area Change
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