A comparison of the mixing characteristics in single- and two-phase grid-generated turbulent flow systems
(2004) In Chemical Engineering & Technology 27(6). p.662-670- Abstract
- The mixing process is studied in grid-generated turbulent flow for single- and bubbly two-phase flow systems. Concentration and mixing characteristics in the liquid phase are measured with the aid of a PLIF/PLIF arrangement. A nearly isotropic turbulent flow field is generated at the center of the vertical pipe by using a honeycomb, three grids and a contraction. In two-phase flow experiments, air bubbles were injected into the flow from a rectangular grid, with mesh size M = 6 mm, which is placed midway between two circular grids each with a mesh size of M = 2 mm. For single-phase flow, the normalized mean concentration cross-stream profiles have rather similar Gaussian shapes, and the cross-stream profiles of the normalized... (More)
- The mixing process is studied in grid-generated turbulent flow for single- and bubbly two-phase flow systems. Concentration and mixing characteristics in the liquid phase are measured with the aid of a PLIF/PLIF arrangement. A nearly isotropic turbulent flow field is generated at the center of the vertical pipe by using a honeycomb, three grids and a contraction. In two-phase flow experiments, air bubbles were injected into the flow from a rectangular grid, with mesh size M = 6 mm, which is placed midway between two circular grids each with a mesh size of M = 2 mm. For single-phase flow, the normalized mean concentration cross-stream profiles have rather similar Gaussian shapes, and the cross-stream profiles of the normalized root-mean-square (RMS) values of concentration were found to be quite similar. Cross-stream profiles of the mean concentration, for bubbly two-phase flow, were also found to be quite similar, but they did not have the Gaussian shape of the profiles for single-phase flow. Almost self-similar behavior was also found for the RMS values of the concentration in two-phase systems. The turbulent diffusion coefficient in the liquid phase was also calculated. At the center of the plume, the flow was found to have a periodic coherent structure, probably of vortex shedding character. Observations showed that the period of oscillation is higher in the case of two-phase flow than in single-phase flow. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/139193
- author
- Moghaddas, Jafar Sadegh LU ; Trägårdh, Christian LU ; Östergren, Karin LU and Revstedt, Johan LU
- organization
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Chemical Engineering & Technology
- volume
- 27
- issue
- 6
- pages
- 662 - 670
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- wos:000222129500008
- scopus:3042698243
- ISSN
- 1521-4125
- DOI
- 10.1002/ceat.200401986
- language
- English
- LU publication?
- yes
- id
- 8ffc1ee0-c3e0-4ae2-8127-d7f50894307c (old id 139193)
- date added to LUP
- 2016-04-01 12:31:15
- date last changed
- 2023-09-02 10:36:12
@article{8ffc1ee0-c3e0-4ae2-8127-d7f50894307c,
abstract = {{The mixing process is studied in grid-generated turbulent flow for single- and bubbly two-phase flow systems. Concentration and mixing characteristics in the liquid phase are measured with the aid of a PLIF/PLIF arrangement. A nearly isotropic turbulent flow field is generated at the center of the vertical pipe by using a honeycomb, three grids and a contraction. In two-phase flow experiments, air bubbles were injected into the flow from a rectangular grid, with mesh size M = 6 mm, which is placed midway between two circular grids each with a mesh size of M = 2 mm. For single-phase flow, the normalized mean concentration cross-stream profiles have rather similar Gaussian shapes, and the cross-stream profiles of the normalized root-mean-square (RMS) values of concentration were found to be quite similar. Cross-stream profiles of the mean concentration, for bubbly two-phase flow, were also found to be quite similar, but they did not have the Gaussian shape of the profiles for single-phase flow. Almost self-similar behavior was also found for the RMS values of the concentration in two-phase systems. The turbulent diffusion coefficient in the liquid phase was also calculated. At the center of the plume, the flow was found to have a periodic coherent structure, probably of vortex shedding character. Observations showed that the period of oscillation is higher in the case of two-phase flow than in single-phase flow.}},
author = {{Moghaddas, Jafar Sadegh and Trägårdh, Christian and Östergren, Karin and Revstedt, Johan}},
issn = {{1521-4125}},
language = {{eng}},
number = {{6}},
pages = {{662--670}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Chemical Engineering & Technology}},
title = {{A comparison of the mixing characteristics in single- and two-phase grid-generated turbulent flow systems}},
url = {{http://dx.doi.org/10.1002/ceat.200401986}},
doi = {{10.1002/ceat.200401986}},
volume = {{27}},
year = {{2004}},
}