Investigation of oscillations and anomalous transport in a hydrogen hollow cathode discharge by a spatially three-dimensional two-fluid model

1998 ◽  
Vol 40 (11) ◽  
pp. 1845-1867 ◽  
Author(s):  
W Biel ◽  
H Kempkens ◽  
J Uhlenbusch
Keyword(s):  
Hollow Cathode ◽  
Fluid Model ◽  
Three Dimensional ◽  
Anomalous Transport ◽  
Hollow Cathode Discharge ◽  
Two Fluid Model ◽  
Two Fluid

Numerical Analysis of Heat Transfer Test of Supercritical Water in a Tube Using the Three-Dimensional Two-Fluid Model Code

2008 ◽  
Author(s):  
Takeharu Misawa ◽  
Hiroyuki Yoshida ◽  
Hidesada Tamai ◽  
Kazuyuki Takase
Keyword(s):  
Heat Transfer ◽  
Fluid Model ◽  
Three Dimensional ◽  
Design Procedure ◽  
Supercritical Pressure ◽  
Thermal Design ◽  
Energy Agency ◽  
Pressure Region ◽  
Two Fluid Model ◽  
Two Fluid

The three-dimensional two-fluid model analysis code ACE-3D is developed in Japan Atomic Energy Agency for the thermal design procedure on two-phase flow thermal-hydraulics of light water-cooled reactors. In order to perform thermal hydraulic analysis of SCWR, ACE-3D is enhanced to supercritical pressure region. As a result, it is confirmed that transient change in subcritical and supercritical pressure region can be simulated smoothly using ACE-3D, that ACE-3D can predict the results of the past heat transfer experiment in the supercritical pressure condition, and that introduction of thermal conductivity effect of the wall restrains fluctuation of wall.

scholarly journals Simulation of Free Surface Compressible Flows via a Two Fluid Model

2008 ◽  
Author(s):  
Fre´de´ric Dias ◽  
Denys Dutykh ◽  
Jean-Michel Ghidaglia
Keyword(s):  
Free Surface ◽  
Wave Breaking ◽  
Compressible Flows ◽  
Fluid Model ◽  
Three Dimensional ◽  
Two Fluids ◽  
Equation Of States ◽  
Two Fluid Model ◽  
Velocity Pressure ◽  
Two Fluid

The purpose of this communication is to discuss the simulation of a free surface compressible flow between two fluids, typically air and water. We use a two fluid model with the same velocity, pressure and temperature for both phases. In such a numerical model, the free surface becomes a thin three dimensional zone. The present method has at least three advantages: (i) the free-surface treatment is completely implicit; (ii) it can naturally handle wave breaking and other topological changes in the flow; (iii) one can easily vary the Equation of States (EOS) of each fluid (in principle, one can even consider tabulated EOS). Moreover, our model is unconditionally hyperbolic for reasonable EOS.

Flow Characteristics in an Airlift Membrane Bioreactor

2009 ◽  
Vol 4 (5) ◽  
Author(s):  
Amirhossein Khalili ◽  
MR Mehrnia ◽  
Navid Mostoufi ◽  
Mohammad Sarrafzadeh
Keyword(s):  
Shear Stress ◽  
Membrane Bioreactor ◽  
Fluid Model ◽  
Membrane Surface ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Liquid Level ◽  
Two Fluid Model ◽  
Two Fluid

Effect of changing the liquid level in an airlift membrane bioreactor of 0.7 m height, 0.24 m width and 0.18 m depth was studied both experimentally and by simulation. Three-dimensional simulations of the airlift membrane bioreactor were carried out at two different liquid levels above the membrane. The simulations were based on the two-fluid model with the standard k–? model for the turbulence. The results showed that by lowering the liquid level, the quality of mixing and uniformity of the velocity distribution of liquid phase in the riser would be improved while the shear stress on the membrane surface would be reduced. Higher shear stress on the membrane surface at high levels of liquid minimizes the extent to which particles settle on the membrane, thus, fouling will be reduced and flux of liquid through membrane will be enhanced. Moreover, it was shown that by lowering the liquid level, the fraction of air in the downcomers becomes lower.

Sign in / Sign up

Export Citation Format

Share Document