Experimental and numerical studies on the flow characteristics and separation properties of dispersed liquid-liquid flows
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Published version
Author(s)
Voulgaropoulos, Victor
Jamshidi, Rashid
Mazzei, Luca
Angeli, Panagiota
Type
Journal Article
Abstract
The local dynamics of spatially developing liquid-liquid dispersed flows at low superficial velocities, ranging from 0.2 to 0.8 m s−1, are investigated. The dispersions are generated with an in-line static mixer. Detailed measurements with laser-based diagnostic tools are conducted at two axial pipe locations downstream of the mixer, namely, at 15 and 135 equivalent pipe diameters. Different flow patterns are recorded, and their development along the streamwise direction is shown to depend on the initial size and concentration of the drops as well as the mixture velocity. The drop size is accurately predicted by an empirical formula. The variations in drop concentration over the pipe cross-section along the pipe result in local changes of the physical properties of the mixture and consequently in asymmetrical velocity profiles, with the maxima of the velocity located in the drop-free region. Computational fluid dynamics simulations based on a mixture approach predict the experimental results close to the experimental uncertainties for the majority of the cases. The simulation results reveal that gravity and lift forces, as well as shear-induced diffusion are the most important mechanisms affecting the drop migration. It is found that the drops behave as suspensions of rigid spheres for the conditions investigated, despite the deformation effects, which are found experimentally to be stronger at the densely packed region.
Date Issued
2019-07
Date Acceptance
2019-06-01
Citation
Physics of Fluids, 2019, 31 (7), pp.073304-1-073304-16
ISSN
1070-6631
Publisher
AIP Publishing
Start Page
073304-1
End Page
073304-16
Journal / Book Title
Physics of Fluids
Volume
31
Issue
7
Copyright Statement
© 2019 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Identifier
https://aip.scitation.org/doi/10.1063/1.5092720
Subjects
01 Mathematical Sciences
02 Physical Sciences
09 Engineering
Fluids & Plasmas
Publication Status
Published
Date Publish Online
2019-07-11