The transition to aeration in turbulent two-phase mixing in stirred vessels
File(s)
Author(s)
Type
Journal Article
Abstract
We consider the mixing dynamics of an air–liquid system driven by the rotation of a pitched blade turbine (PBT) inside an open, cylindrical tank. To examine the flow and interfacial dynamics, we use a highly parallelised implementation of a hybrid front-tracking/level-set method that employs a domain-decomposition parallelisation strategy. Our numerical technique is designed to capture faithfully complex interfacial deformation, and changes of topology, including interface rupture and dispersed phase coalescence. As shown via transient, a three-dimensional (3-D) LES (large eddy simulation) using a Smagorinsky–Lilly turbulence model, the impeller induces the formation of primary vortices that arise in many idealised rotating flows as well as several secondary vortical structures resembling Kelvin–Helmholtz, vortex breakdown, blade tip vortices and end-wall corner vortices. As the rotation rate increases, a transition to ‘aeration’ is observed when the interface reaches the rotating blades leading to the entrainment of air bubbles into the viscous fluid and the creation of a bubbly, rotating, free surface flow. The mechanisms underlying the aeration transition are probed as are the routes leading to it, which are shown to exhibit a strong dependence on flow history.
Date Issued
2022-10-21
Online Publication Date
2022-11-11T15:38:38Z
Date Acceptance
2022-10-01
ISSN
0003-6994
Publisher
Springer
Start Page
1
End Page
20
Journal / Book Title
Flow, Turbulence and Combustion
Volume
2
Copyright Statement
© The Author(s), 2022. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
License URI
Identifier
https://www.cambridge.org/core/journals/flow/article/transition-to-aeration-in-turbulent-twophase-mixing-in-stirred-vessels/6C39B2AB37A3A544A803DE089B3A0A70
Subjects
09 Engineering
Mechanical Engineering & Transports
Fluids & Plasmas
Publication Status
Published
Article Number
E30
Date Publish Online
2022-10-21