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Large eddy simulation of microbubble dispersion and flow field modulation in vertical channel flows
Author(s) -
Asiagbe Kenneth S.,
Fairweather Michael,
Njobuenwu Derrick O.,
Colombo Marco
Publication year - 2019
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.16509
Subject(s) - bubble , mechanics , turbulence , reynolds number , large eddy simulation , microbubbles , flow (mathematics) , direct numerical simulation , physics , acoustics , ultrasound
Turbulent liquid–gas vertical channel flows laden with microbubbles are investigated using large eddy simulation (LES) two‐way coupled to a Lagrangian bubble tracking technique. Upward and downward flows at shear Reynolds numbers of Re τ = 150 and 590 are analyzed for three different microbubble diameters of 110, 220, and 330 μm. Predicted results are compared with published direct numerical simulation results although, with respect to comparable studies available in the literature, the range of bubble diameters and shear Reynolds numbers considered herein is extended to larger values. Microbubble concentration profiles are analyzed, with the microbubbles segregating at the wall in upflow conditions and moving toward the channel centre in downflow. The various forces acting on the bubbles, and the effect of the flow turbulence on the bubble concentration, are considered and quantified. Overall, the results suggest that the level of detail achievable with LES is sufficient to predict the fluid structures impacting bubble behavior. Therefore, LES coupled with Lagrangian bubble tracking shows promise for enabling the reliable prediction of bubble‐laden flows that are of industrial relevance. © 2018 American Institute of Chemical Engineers AIChE J, 65: 1325–1339, 2019