scholarly journals Transition of interfacial area concentration distribution of air-water two-phase flow downstream of single horizontal tube and horizontal tube bundle

2016 ◽  
Vol 82 (835) ◽  
pp. 15-00608-15-00608
Author(s):  
Atsushi ISHIKAWA ◽  
Kenji YOSHIDA ◽  
Isao KATAOKA
Author(s):  
Tatsuya Hazuku ◽  
Naohisa Tamura ◽  
Norihiro Fukamachi ◽  
Tomoji Takamasa ◽  
Takashi Hibiki ◽  
...  

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.


2010 ◽  
Vol 240 (9) ◽  
pp. 2329-2337 ◽  
Author(s):  
Sidharth Paranjape ◽  
Mamoru Ishii ◽  
Takashi Hibiki

Author(s):  
Hiroshi Goda ◽  
Seungjin Kim ◽  
Sidharth S. Paranjape ◽  
Joshua P. Finch ◽  
Mamoru Ishii ◽  
...  

The local interfacial structure for vertical air-water co-current downward two-phase flow was investigated under adiabatic conditions. A multi-sensor conductivity probe was utilized in order to acquire the local two-phase flow parameters. The present experimental loop consisted of 25.4 mm and 50.8 mm ID round tubes as test sections. The measurement was performed at three axial locations: L/D = 13, 68 and 133 for the 25.4 mm ID loop and L/D = 7, 34, 67 for the 50.8 mm ID loop, in order to study the axial development of the flow. A total of 7 and 10 local measurement points along the tube radius were chosen for the 25.4 mm ID loop and the 50.8 mm ID loop, respectively. The experimental flow conditions were determined within bubbly flow regime. The acquired local parameters included the void fraction, interfacial area concentration, bubble interface frequency, bubble Sauter mean diameter, and interfacial velocity.


2021 ◽  
Author(s):  
Xiang Zhang ◽  
Minjun Peng ◽  
Tenglong Cong ◽  
Chuan Lu ◽  
Chenyang Wang

Abstract The interfacial area concentration (IAC) is an important parameter in the calculation of interfacial transfers in two-fluid model, which can affect the accuracy of the boiling simulations. In this paper, an improved IAC model based on drag force and drift velocity is obtained, which can make full use of the experimental data and the models of the drag force and the drift velocity to avoid the shortage of IAC algebraic model in two-phase flow simulations theoretically. The improved model is validated by the DEBORA boiling flow experiment data. The reasonable radial distributions of void fraction, liquid temperature and phase velocity can be obtained, which indicates that the improved IAC model coupled in boiling flow model can be applied in CFD simulation of two-phase boiling flow. The improved model provides a new calculation approach for the IAC in the boiling flow with multi flow regimes.


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