scholarly journals Three-dimensional fluidized beds with rough spheres: Validation of a Two Fluid Model by Magnetic Particle Tracking and discrete particle simulations

2017 ◽  
Vol 174 ◽  
pp. 238-258 ◽  
Author(s):  
Lei Yang ◽  
J.T. Padding ◽  
K.A. Buist ◽  
J.A.M. Kuipers
Author(s):  
Takeharu Misawa ◽  
Hiroyuki Yoshida ◽  
Hidesada Tamai ◽  
Kazuyuki Takase

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.


Author(s):  
Fre´de´ric Dias ◽  
Denys Dutykh ◽  
Jean-Michel Ghidaglia

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.


Author(s):  
Xiaoling Wang ◽  
Liang Yu ◽  
Jun Wang

Abstract The Two-Fluid Model (TFM) using the Kinetic Theory of Granular Flow (KTGF) was applied to simulate 3-D dense fluidized beds with different complex internals. The slugging fluidization was found in the simulated results. When the internals were placed into the reactors, the simulated results showed that the slugs were broken up and bubbling fluidization was formed instead of slugging fluidization. The formation, growth, size, and shape of bubbles were validated to ensure a reasonable prediction. Furthermore, the simulated pressure drop was compared with the corresponding experimental data from the dense fluidized beds with different complex internals, and good agreements were observed. Finally, the flow nonuniformity in the dense fluidized beds was evaluated by a developed method. This method extended Radial Nonuniformity Index (RNI) to Face Nonuniformity Index (FNI) and Volume Nonuniformity Index (VNI). From the calculated FNI and VNI, the fluidization quality of the fluidized beds was quantitatively judged as follows: No.3 > No.1> No.2 > No.4 > Without Internal.


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