Fatehifar, M. orcid.org/0000-0002-8770-729X, Revell, A. orcid.org/0000-0001-7435-1506, Jabbari, M. orcid.org/0000-0003-3615-969X et al. (1 more author) (2023) A numerical analysis of particle encapsulation in a flow-focusing droplet generation device. Physics of Fluids, 35 (11). 113317. ISSN 1070-6631
Abstract
In this paper, the process of encapsulating solid particle(s) into liquid droplets in a high-throughput flow-focusing microchannel is investigated numerically. Open source software is used, which computes fluid flow in an Eulerian framework and particle dynamics with a Lagrangian approach. Previous studies have demonstrated that if no action is taken, particles suspended in a liquid passing through a flowfocusing microchannel will be encapsulated at random. This is perhaps unsurprising, but in one such study, less than 35% of droplets were found to contain exactly one particle. The two aims of this study are (i) to explore the flow patterns arising in a microfluidic channel and (ii) to elucidate the effect of salient governing parameters on encapsulation efficiency (i.e., the fraction of droplets encapsulating one particle) by focusing on ordering the particles before reaching the droplet generation section. Following validation against experimental reference data, the capillary number is varied across the three droplet generation regimes: squeezing, dripping, and jetting. We demonstrate that under certain conditions, an encapsulation frequency of 100% can be achieved with ordered particles, but in most cases, this is significantly lower. We examine the flow field to help understand how this non-uniform distribution of particles occurs. Notably, we find the dripping to be the best option for particle encapsulation and in this case extend the study to explore the effect of junction angle, finding that an angle of 60° is the most favorable. Improved understanding of the encapsulation process derived from this study can help to improve design of high-throughput droplet generation microfluidic systems.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023 Author(s). Published under an exclusive license by AIP Publishing. The following article has been accepted for publication in Physics of Fluids. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Engineering Thermofluids, Surfaces & Interfaces (iETSI) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 09 Feb 2024 12:27 |
Last Modified: | 19 Dec 2024 16:38 |
Status: | Published |
Publisher: | American Institute of Physics |
Identification Number: | 10.1063/5.0172483 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:208975 |