The analysis of phase separation and phase distribution phenomena using two-fluid models

A particle interaction method called MPS (Moving Particle Semi-Implicit) has been developed in recent years, which formulates the differential operators in Navier-Stokes' equation as interactions between particles characterized by a kernel function and adopts a mesh-free algorithm. This method is suitable especially for treating fluid breakup. We have extended this method to a two-fluid (liquid-liquid and gas-liquid) system and introduced a potential-type surface tension to calculate the two-phase flow without experimental correlation. With this extended method, a several number of two-phase flow experiments were analyzed successfully as reported in our previous paper. Herein, as one of the verification studies, the experiment by Valukina et al. was analyzed to show that our method could reproduce the bubble size effect on the radial void distribution in a circular tube. The experiment showed that the radial void distribution changes drastically as the bubble size changes. Our previous work with SIMMER-IV code which has a general solver for multi-phase flows revealed that the "lateral lift force" and "wall force" should be introduced into the momentum conservation equation to reproduce the bubble size effect. We evaluated these forces using the velocities of particles calculated by our particle method and compared with the SIMMER-IV results.

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“…23) In this analysis, C t is used which is obtained with an experiment by Beyerlein et al 24) and its value is as follows:…”

Section: Valukina's Experimentsmentioning

confidence: 99%

Analysis of the Void Distribution in a Circular Tube with the Two-Fluid Particle Interacthion Method

Shirakawa

Horie

Yamamoto

et al. 2001

Journal of Nuclear Science and Technology

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“…These phenomena of phase distribution have been associated with turbulence in the liquid phase, and with the lift forces acting on the bubbles. The phase distribution phenomena have been studied by Drew and Lahey (1982), Zun (1988), Lahey (1990), and Lopez de Bertodano et al (1990), among others.…”

Section: Bubblyflow Studiesmentioning

confidence: 99%

Full-Volume, Three-Dimensional, Transient Measurements of Bubbly Flows Using Particle Tracking Velocimetry and Shadow Image Velocimetry Coupled with Pattern Recognition Techniques

Hassan¹

2001

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This is the third phase report of the present NEER project. The overall goal, as d e s m i d in the initial report (report fbr phase l), was to develop a state-of-the-art; non-intrusive diagnostic tool to perform simultaneous measurements of both the temporal and threedimensional spatial velocity of the two phases of a bubbly flow. These measurements are required to provide a ikwndation for studying the constitutive closure relations needed in computational fluid dynamics and best-estimate thermal hydraulic codes employed in nuclear reactor safety analysis and severe accident simulation. Such kinds of I11-field measurements are not achievable through the commonly used point-measurement techniques, such as hot wire, conductance probe, laser Doppler anemometry, etc. The results c8fl also be used in several other applications, such as the dynamic transport of pollutants in water or studies of the dispersion of hazardous waste. A hybrid of the stereoscopic Particle Tracking Velocimetry (PTV) and the Shadow Image Velocimetry (SIV) flow measurement techniques was developed to provide threedimensional full-volume and transient velocity fields of the phases of a bubbly flow.This hybrid flow measurement technique was applied to provide us with the shape%d trajectory of a single air bubble rising in stagnant water, in a restricted medium. Pattern recognition algorithms were used to track the seed tracers embedded in the flow. These algorithms were proven to accurately describe the flow field in regions of low and high velocity gradients. Two tracking were used an Architecture Resonance Theory 2 Neural Network (ART2 NN) and the Spring Model (SM). The ART2 NN tracks tracer particles during h u r consecutive M e s , so it provides not only the velocity vector, but also the acceleration in a Lagrangian reference fiame. For regions of high velocity gradient, the SM was able to accurately track the tracer particles within two consecutive fkmes. These two pattern recognition-based algorithms were applied independently to the flow images. By combining the information fiom both tracking techniques, the fullvolume, three-dimensional velocity field was determined. The ART2 NN provided infbrmation of regions surrounding the rising bubble, while the SM descriied the flow in the bubble wake. The developed imaging and pattern recognition techniques used for this study can also be applied to medical imaging. 1In the Phase I report, a description of the constructed test hcility was presented. The camera calibration technique and a method to reduce refiaction problems were developed and presented. In addition, the PTV and SIV flow measurement techniques and tracking routines the ART2 NN and the SM were described and validated. During Phase n, the bubble shape and trajectory of the dispersed phase were obtained utilizing the developed state-of-the-art SIV technique. The wall influence on the shape and motion of the bubble was investigated. The magnitude and coefficients of the drag and lift forces acting on the bubble were also infenred fio...

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“…There are a variety of approaches, such as ensemble, space and time, and various combinations. Many researchers have been studying the averaging problem, Standart (Standart, 1964), Drew and Segal (Drew,197 I), Travis, Harlow, and Amsden (Travis, 1974), Delhaye (Delhaye, 1974), Ishii (Ishii, 1975), Harlow and Amsden (Harlow, 1975), Nigmatulin (Nigmatulin, 1979), Drew and Lahey, (Drew, 1979a), Hassanizadeh and Gray (Hassanizadeh, 1979), Banejee and Chan (Banejee, 1980), Ishii and Mishima (Ishii, 1984), Stewart and Wendorff (Stewart, 1984), Dobran (Dobran, 1984(Dobran, , 1985, Kashiwa (Kashiwa, 1987 (Kashiwa, 1994), Pauchon and Banerjee (Pauchon, 1986(Pauchon, , 1988), Arnold, Drew, and Lahey (Arnold, 1988), Lahey (Lahey, 1989(Lahey, , 1990(Lahey, , 1991, Lahey, Park, and Drew (Lahey, 1993) and Grau and Canter0 (Grau, 1994). It is interesting to note that the basic forms of the various mass, momentum and energy equations are similar.…”

Section: Macroscopic and Multi-fluid Modelsmentioning

confidence: 99%

“…Given eqn (4.24) we are going to re-define the drag force as (Lahey, 1990) (4.25) so that the total drag force is proportional to the interfacial area concentration.…”

Section: Interfluid Momentum Transfermentioning

confidence: 99%

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Modeling interfacial area transport in multi-fluid systems

Yarbro

1996

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The analysis of phase separation and phase distribution phenomena using two-fluid models

Cited by 69 publications

References 26 publications

Analysis of the Void Distribution in a Circular Tube with the Two-Fluid Particle Interacthion Method

Analysis of the Void Distribution in a Circular Tube with the Two-Fluid Particle Interacthion Method

Full-Volume, Three-Dimensional, Transient Measurements of Bubbly Flows Using Particle Tracking Velocimetry and Shadow Image Velocimetry Coupled with Pattern Recognition Techniques

Modeling interfacial area transport in multi-fluid systems

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