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Flow physics and mixing quality in a confined impinging jet mixer

Due to their ability to provide efficient mixing at small scales, confined impinging jet mixers (CIJMs) are employed widely in nanoparticle assembly processes such as flash nanoprecipitation and flash nanocomplexation, which require rapid mixing. In this mixing device, two jets from opposite directi...

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Autores principales: Hao, Yue, Seo, Jung-Hee, Hu, Yizong, Mao, Hai-Quan, Mittal, Rajat
Formato: Online Artículo Texto
Lenguaje:English
Publicado: AIP Publishing LLC 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7124763/
https://www.ncbi.nlm.nih.gov/pubmed/32266109
http://dx.doi.org/10.1063/5.0002125
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author Hao, Yue
Seo, Jung-Hee
Hu, Yizong
Mao, Hai-Quan
Mittal, Rajat
author_facet Hao, Yue
Seo, Jung-Hee
Hu, Yizong
Mao, Hai-Quan
Mittal, Rajat
author_sort Hao, Yue
collection PubMed
description Due to their ability to provide efficient mixing at small scales, confined impinging jet mixers (CIJMs) are employed widely in nanoparticle assembly processes such as flash nanoprecipitation and flash nanocomplexation, which require rapid mixing. In this mixing device, two jets from opposite directions impinge directly on each other forming a thin shear layer that breaks down rapidly into small flow structures. This enables effective mixing of the species transported by each jet by drastically reducing the diffusion distance. In the present study, the mixing performance of a commonly used cylindrical CIJM is examined by direct numerical simulations. Analysis of the simulation results indicates that the interaction of the shear layer with the inner walls of the CIJM is critical in inducing a range of instabilities in the impinging jet flow. By examining flow structures, statistical quantities, and metrics, we have characterized and quantified the mixing quality of a binary mixture in the CIJM. Product uniformity in processes such as precipitation and complexation is expected to depend on the residence time of the constituents, and this quantity is also calculated and compared for the cases with different jet Reynolds numbers. The jet Reynolds numbers of Re = 200, 600, and 1000 are considered, and the simulation results show that the CIJM achieves very good mixing for the Re = 600 and Re = 1000 cases. It is also found that the Re = 600 case performs slightly better than the other cases in terms of uniformity of the residence time. These quantitative analyses offer useful insights into the mechanism of nanoparticle size control and uniformity afforded by the unique flow physics and mixing characteristics in the CIJMs.
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spelling pubmed-71247632020-04-07 Flow physics and mixing quality in a confined impinging jet mixer Hao, Yue Seo, Jung-Hee Hu, Yizong Mao, Hai-Quan Mittal, Rajat AIP Adv Regular Articles Due to their ability to provide efficient mixing at small scales, confined impinging jet mixers (CIJMs) are employed widely in nanoparticle assembly processes such as flash nanoprecipitation and flash nanocomplexation, which require rapid mixing. In this mixing device, two jets from opposite directions impinge directly on each other forming a thin shear layer that breaks down rapidly into small flow structures. This enables effective mixing of the species transported by each jet by drastically reducing the diffusion distance. In the present study, the mixing performance of a commonly used cylindrical CIJM is examined by direct numerical simulations. Analysis of the simulation results indicates that the interaction of the shear layer with the inner walls of the CIJM is critical in inducing a range of instabilities in the impinging jet flow. By examining flow structures, statistical quantities, and metrics, we have characterized and quantified the mixing quality of a binary mixture in the CIJM. Product uniformity in processes such as precipitation and complexation is expected to depend on the residence time of the constituents, and this quantity is also calculated and compared for the cases with different jet Reynolds numbers. The jet Reynolds numbers of Re = 200, 600, and 1000 are considered, and the simulation results show that the CIJM achieves very good mixing for the Re = 600 and Re = 1000 cases. It is also found that the Re = 600 case performs slightly better than the other cases in terms of uniformity of the residence time. These quantitative analyses offer useful insights into the mechanism of nanoparticle size control and uniformity afforded by the unique flow physics and mixing characteristics in the CIJMs. AIP Publishing LLC 2020-04-02 /pmc/articles/PMC7124763/ /pubmed/32266109 http://dx.doi.org/10.1063/5.0002125 Text en © 2020 Author(s). 2158-3226/2020/10(4)/045105/10/$0.00 All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Regular Articles
Hao, Yue
Seo, Jung-Hee
Hu, Yizong
Mao, Hai-Quan
Mittal, Rajat
Flow physics and mixing quality in a confined impinging jet mixer
title Flow physics and mixing quality in a confined impinging jet mixer
title_full Flow physics and mixing quality in a confined impinging jet mixer
title_fullStr Flow physics and mixing quality in a confined impinging jet mixer
title_full_unstemmed Flow physics and mixing quality in a confined impinging jet mixer
title_short Flow physics and mixing quality in a confined impinging jet mixer
title_sort flow physics and mixing quality in a confined impinging jet mixer
topic Regular Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7124763/
https://www.ncbi.nlm.nih.gov/pubmed/32266109
http://dx.doi.org/10.1063/5.0002125
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