In the heart of a micro-mixer: characterisation of liquid-liquid flow hydrodynamics inside an advanced-flow micro-reactor
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
The hydrodynamic characteristics of liquid-liquid flows in a micro-mixing plate with a ‘heart/spade’ geometry and a
hydraulic diameter of ∼ 0.36 mm at the contraction point are studied experimentally in the Reynolds number range of
250 − 1, 000. Localised optical observations of the two-phase flow within the micro-mixing device units are performed
using a high-speed camera in combination with an LED-induced fluorescence imaging technique. A qualitative interpreta tion of the instantaneous images enabled the development of a regime map with three stable flow patterns, each with a
metastable transitional state. The formation of secondary flows and recirculation zones resulted in the breakup of interfaces
and fragmentation of droplets. The droplet size distribution of an MTBE-water dispersion is studied across a broad range
of the dispersed phase (water) ratios, ϕd = 0.091 − 0.714. The resulting Sauter mean diameter of water droplets is used
to evaluate the improvement in the specific surface area and was correlated as a function of the energy dissipation rate
and the Reynolds and Weber numbers.
hydraulic diameter of ∼ 0.36 mm at the contraction point are studied experimentally in the Reynolds number range of
250 − 1, 000. Localised optical observations of the two-phase flow within the micro-mixing device units are performed
using a high-speed camera in combination with an LED-induced fluorescence imaging technique. A qualitative interpreta tion of the instantaneous images enabled the development of a regime map with three stable flow patterns, each with a
metastable transitional state. The formation of secondary flows and recirculation zones resulted in the breakup of interfaces
and fragmentation of droplets. The droplet size distribution of an MTBE-water dispersion is studied across a broad range
of the dispersed phase (water) ratios, ϕd = 0.091 − 0.714. The resulting Sauter mean diameter of water droplets is used
to evaluate the improvement in the specific surface area and was correlated as a function of the energy dissipation rate
and the Reynolds and Weber numbers.
Date Issued
2025-11-01
Date Acceptance
2025-08-20
Citation
Microfluidics and Nanofluidics, 2025, 29 (11)
ISSN
1613-4982
Publisher
Springer Science and Business Media LLC
Journal / Book Title
Microfluidics and Nanofluidics
Volume
29
Issue
11
Copyright Statement
© The Author(s) 2025 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
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Publication Status
Published
Article Number
75
Date Publish Online
2025-10-09