Development of interfacial area concentration correlations for small and large bubbles in gas-liquid two-phase flows

The purpose of this paper is to report on the development and assessment of approximate Riemann solver methods for the discretization of non-linear non-conservative systems arising in the simulation of two-phase flows. These methods are able to treat general two-phase flow systems with realistic state equations and are flexible enough to be applied on any mesh type, structured as well as unstructured. We will detail models that go from the basic 6 equation two-fluid model to the coupling of this system with one or more transport equations, for instance on volumetric interfacial area concentration, or on partial void fractions of groups of bubbles (MUlti-Size-Group model). This kind of transport equation is useful to predict at a finer level the interfacial patterns or bubble size distribution and takes account of coalescence or breakup rates of inclusions. We make a glimpse at the choices made regarding this aspect. Different physico-numerical benchmarks are provided in order to illustrate the numerical and physical modeling. Confrontation with experimental or analytical reference data are performed whenever possible. Computer simulations are performed using OVAP, a new multidimensional CFD code.

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Axial Development of Vertical Upward Bubbly Flow in a Minipipe

Heat Transfer: Volume 2 ◽

10.1115/ht2005-72413 ◽

2005 ◽

Cited By ~ 4

Author(s):

Tatsuya Hazuku ◽

Naohisa Tamura ◽

Norihiro Fukamachi ◽

Tomoji Takamasa ◽

Takashi Hibiki ◽

...

Keyword(s):

Void Fraction ◽

Two Phase Flow ◽

Constitutive Relations ◽

Interfacial Area ◽

Phase Flow ◽

Two Phase ◽

Flow Measurements ◽

Local Flow ◽

Interfacial Area Concentration ◽

Drift Flux Model

Accurate prediction of the interfacial area concentration is essential to successful development of the interfacial transfer terms in the two-fluid model. Mechanistic modeling of the interfacial area concentration entirely relies on accurate local flow measurements over extensive flow conditions and channel geometries. From this point of view, accurate measurements of flow parameters such as void fraction, interfacial area concentration, gas velocity, bubble Sauter mean diameter, and bubble number density were performed by the image processing method at five axial locations in vertical upward bubbly flows using a 1.02 mm-diameter pipe. The frictional pressure loss was also measured by a differential pressure cell. In the experiment, the superficial liquid velocity and the void fraction ranged from 1.02 m/s to 4.89 m/s and from 0.980% to 24.6%, respectively. The obtained data give near complete information on the time-averaged local hydrodynamic parameters of two-phase flow. These data can be used for the development of reliable constitutive relations which reflect the true transfer mechanisms in two-phase flow. As the first step to understand the flow characteristics in mini-channels, the applicability of the existing drift-flux model, interfacial area correlation, and frictional pressure correlation was examined by the data obtained in the mini-channel.

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Modeling and measurement of interfacial area concentration in two-phase flow

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2009.11.009 ◽

2010 ◽

Vol 240 (9) ◽

pp. 2329-2337 ◽

Cited By ~ 23

Author(s):

Sidharth Paranjape ◽

Mamoru Ishii ◽

Takashi Hibiki

Keyword(s):

Two Phase Flow ◽

Interfacial Area ◽

Phase Flow ◽

Two Phase ◽

Interfacial Area Concentration

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Recent Progress in the Studies of Gas-Liquid Two-Phase Flows at Microgravity Conditions

Volume 2: Symposia, Parts A, B, and C ◽

10.1115/fedsm2003-45662 ◽

2003 ◽

Author(s):

Tomoji Takamasa ◽

Takashi Hibiki

Keyword(s):

Recent Progress ◽

Interfacial Area ◽

Phase System ◽

Two Phase Flows ◽

Two Phase ◽

Interfacial Area Transport ◽

Drift Flux ◽

Wide Range ◽

Microgravity Conditions ◽

Heat Loads

In a thermal system of spacecraft, two-phase flow system now is an excellent alternative to the conventional single-phase system in transporting large amount of thermal energy at a uniform temperature regardless of variations in the heat loads. In addition, two-phase flows exist in a wide range of applications and enabling technologies in space. This report outlines recent progress in the studies of gas-liquid two-phase flows at microgravity conditions, especially for which regarding to interfacial area transport and drift flux.

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