Void fraction in vertical tubes under low pressure of steam-water flow

2012 ◽  
Vol 59 (1) ◽  
pp. 20-25
Author(s):  
B. F. Balunov ◽  
A. A. Shcheglov ◽  
V. A. Il’in ◽  
V. D. Lychakov ◽  
S. V. Svetlov ◽  
...  
Keyword(s):  
Water Flow ◽  
Void Fraction ◽  
Low Pressure ◽  
Vertical Tubes

scholarly journals Determination of cross-sectional void fraction in a two-phase water flow through a PVC pipe

2021 ◽  
Vol 655 (1) ◽  
pp. 012024
Author(s):  
O.H. Ajesi ◽  
M.B. Latif ◽  
S.T. Gbenu ◽  
C. A. Onumejor ◽  
M. K. Fasasi ◽  
...  
Keyword(s):  
Water Flow ◽  
Void Fraction ◽  
Two Phase ◽  
Cross Sectional ◽  
Flow Through ◽  
Pvc Pipe ◽  
Phase Water

Analysis of RELAP5 Drift-Flux Model for Vertical Subcooled Boiling Flow at Low Pressure Conditions

2000 ◽  
Author(s):  
Boštjan Končar ◽  
Ivo Kljenak ◽  
Borut Mavko
Keyword(s):  
Void Fraction ◽  
Drift Velocity ◽  
Bubbly Flow ◽  
Low Pressure ◽  
Subcooled Boiling ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Boiling Flow ◽  
Flux Model ◽  
Relap5 Code

Abstract The RELAP5/MOD3.2.2 Gamma code was assessed against low pressure boiling flow experiments performed by Zeitoun and Shoukri (1997) in a vertical annulus. The predictions of subcooled boiling bubbly flow showed that the present version of the RELAP5 code underestimates the void fraction increase along the flow and strongly overestimates the vapor drift velocity. It is shown that in the calculations, a higher vapor drift velocity causes a lower interphase drag and may be a possible reason for underpredicted void fraction development. A modification is proposed, which introduces the replacement of the EPRI drift-flux formulation, which is currently incorporated in the RELAP5 code, with the Zuber-Findlay (1965) drift-flux model for the experimental low pressure conditions of the vertical bubbly flow regime. The improved experiment predictions with the modified RELAP5 code are presented and analysed.

CONSIDERATION OF BUOYANCE FORCES WHEN SIMULATING SUPERCRITICAL WATER FLOW IN VERTICAL TUBES

2017 ◽  
Author(s):  
Nataliia Fialko ◽  
◽  
Julii Sherenkovskiy ◽  
Nataliia Meranova ◽  
Serhii Aleshko ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Water Flow ◽  
Supercritical Water ◽  
Flow Characteristics ◽  
Buoyancy Forces ◽  
Vertical Tubes

The results of computer simulation of supercritical water flow in tubes are presented. The regularities of the influence of buoyancy forces on the flow characteristics are investigated.

Flow patterns around gills of pupal net-winged midges (Diptera: Blephariceridae): possible implications for respiration

1995 ◽  
Vol 73 (2) ◽  
pp. 373-382 ◽  
Author(s):  
Gregory D. W. Pommen ◽  
Douglas A. Craig
Keyword(s):  
Water Flow ◽  
Aquatic Insects ◽  
Bluff Body ◽  
Low Pressure ◽  
Flow Patterns ◽  
Matched Pairs ◽  
Reversed Flow

Dye studies of water flow around pupae of species of Blephariceridae show that the pupa and gills act as a "bluff body" and produce matched pairs of vortices, or regions of low pressure, downstream of the gills. Solenoidal vortices are also produced at the bases of the gills, as is reversed flow between the two gills. Bubbles of air produced from the gill plastron of live pupae are considered to be the result of decreased solubility of air in water in the low-pressure regions associated with the gills. We conclude that the pupal gills of Blephariceridae, Simuliidae, and probably other aquatic insects are designed to make use of regions of low pressure for respiratory purposes.

Sign in / Sign up

Export Citation Format

Share Document