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Studies of gas-liquid two-phase flows in horizontal mini tubes using 3D reconstruction and numerical methods

Zhang, Jingzhi LU ; Huang, Nanyan ; Lei, Li ; Liang, Fushun ; Wang, Xinyu and Wu, Zan LU (2020) In International Journal of Multiphase Flow 133.
Abstract

In order to study the characteristics of 3D gas-liquid interfaces, flow pattern transitions, and void fraction in mini tubes, virtual multi-vision experiments and numerical simulations are conducted in a 5.16 mm horizontal tube with air as the dispersed phase and water as the continuous phase. Air and water flow velocities range from 0.024 to 12.330 m/s and from 0.039 to 0.942 m/s, respectively. A simple setup is adopted to capture images synchronously from two orthogonal views with a prism. 3D gas-liquid interfaces of bubbly, slug, and annular flows in horizontal mini tubes are reconstructed in Matlab based on the captured images. Flow pattern transitions and void fractions with 3D interfaces are comprehensively investigated both... (More)

In order to study the characteristics of 3D gas-liquid interfaces, flow pattern transitions, and void fraction in mini tubes, virtual multi-vision experiments and numerical simulations are conducted in a 5.16 mm horizontal tube with air as the dispersed phase and water as the continuous phase. Air and water flow velocities range from 0.024 to 12.330 m/s and from 0.039 to 0.942 m/s, respectively. A simple setup is adopted to capture images synchronously from two orthogonal views with a prism. 3D gas-liquid interfaces of bubbly, slug, and annular flows in horizontal mini tubes are reconstructed in Matlab based on the captured images. Flow pattern transitions and void fractions with 3D interfaces are comprehensively investigated both experimentally and numerically. The numerical results fit well with experimental data in terms of 3D interfaces, cross-sectional and volumetric void fractions. The results show that three flow patterns (bubbly, slug, and annular) are observed experimentally and numerically. The increases in both bubble size and interfacial fluctuation are the main reasons for flow pattern transitions. Two peaks are observed in the Probability Density Functions figures for intermittent flows, while only one peak is obtained for annular flow. The volumetric void fraction fits well with the homogenous model when the gas quality is lower than 0.8, while the slip ratio is around 1. The velocity difference between the two phases increases dramatically at a higher gas quality, leading to a lower void fraction than the predicted value by the homogenous model. The results agree well with empirical correlations with a mean average deviation about 10%, which validates the experimental and numerical methods in the present work.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
3D reconstruction, CFD, Mini tubes, PDF, Two-phase flow, Void fraction
in
International Journal of Multiphase Flow
volume
133
article number
103456
publisher
Elsevier
external identifiers
  • scopus:85090744465
ISSN
0301-9322
DOI
10.1016/j.ijmultiphaseflow.2020.103456
language
English
LU publication?
yes
id
70a484c8-d557-4453-a427-afbb3e8744c6
date added to LUP
2020-09-30 09:27:24
date last changed
2025-04-04 14:36:55
@article{70a484c8-d557-4453-a427-afbb3e8744c6,
  abstract     = {{<p>In order to study the characteristics of 3D gas-liquid interfaces, flow pattern transitions, and void fraction in mini tubes, virtual multi-vision experiments and numerical simulations are conducted in a 5.16 mm horizontal tube with air as the dispersed phase and water as the continuous phase. Air and water flow velocities range from 0.024 to 12.330 m/s and from 0.039 to 0.942 m/s, respectively. A simple setup is adopted to capture images synchronously from two orthogonal views with a prism. 3D gas-liquid interfaces of bubbly, slug, and annular flows in horizontal mini tubes are reconstructed in Matlab based on the captured images. Flow pattern transitions and void fractions with 3D interfaces are comprehensively investigated both experimentally and numerically. The numerical results fit well with experimental data in terms of 3D interfaces, cross-sectional and volumetric void fractions. The results show that three flow patterns (bubbly, slug, and annular) are observed experimentally and numerically. The increases in both bubble size and interfacial fluctuation are the main reasons for flow pattern transitions. Two peaks are observed in the Probability Density Functions figures for intermittent flows, while only one peak is obtained for annular flow. The volumetric void fraction fits well with the homogenous model when the gas quality is lower than 0.8, while the slip ratio is around 1. The velocity difference between the two phases increases dramatically at a higher gas quality, leading to a lower void fraction than the predicted value by the homogenous model. The results agree well with empirical correlations with a mean average deviation about 10%, which validates the experimental and numerical methods in the present work.</p>}},
  author       = {{Zhang, Jingzhi and Huang, Nanyan and Lei, Li and Liang, Fushun and Wang, Xinyu and Wu, Zan}},
  issn         = {{0301-9322}},
  keywords     = {{3D reconstruction; CFD; Mini tubes; PDF; Two-phase flow; Void fraction}},
  language     = {{eng}},
  month        = {{12}},
  publisher    = {{Elsevier}},
  series       = {{International Journal of Multiphase Flow}},
  title        = {{Studies of gas-liquid two-phase flows in horizontal mini tubes using 3D reconstruction and numerical methods}},
  url          = {{http://dx.doi.org/10.1016/j.ijmultiphaseflow.2020.103456}},
  doi          = {{10.1016/j.ijmultiphaseflow.2020.103456}},
  volume       = {{133}},
  year         = {{2020}},
}