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A criterion for when an emulsion drop undergoing turbulent deformation has reached a critically deformed state

Håkansson, Andreas LU ; Crialesi-Esposito, Marco ; Nilsson, Lars LU and Brandt, Luca (2022) In Colloids and Surfaces A: Physicochemical and Engineering Aspects 648.
Abstract
Turbulent breakup in emulsification devices is a dynamic process. Small viscous drops undergo a sequence of oscillations before entering the monotonic deformation phase leading to breakup. The turbulence-interface interactions prior to reaching critical deformation are therefore essential for understanding and modeling breakup. This contribution uses numerical experiments to characterize the critically deformed state (defined as a state from which breakup will follow deterministically, even if no further external stresses would act on the drop). Critical deformation does not coincide with a threshold maximum surface area, as previously suggested. A drop is critically deformed when a neck has formed locally with a curvature such that the... (More)
Turbulent breakup in emulsification devices is a dynamic process. Small viscous drops undergo a sequence of oscillations before entering the monotonic deformation phase leading to breakup. The turbulence-interface interactions prior to reaching critical deformation are therefore essential for understanding and modeling breakup. This contribution uses numerical experiments to characterize the critically deformed state (defined as a state from which breakup will follow deterministically, even if no further external stresses would act on the drop). Critical deformation does not coincide with a threshold maximum surface area, as previously suggested. A drop is critically deformed when a neck has formed locally with a curvature such that the Laplace pressure exceeds that of the smallest of the bulbs connected by the neck. This corresponds to a destabilizing internal flow, further thinning the neck. Assuming that the deformation leads to two spherical bulbs linked by a cylindrical neck, the critical deformation is achieved when the neck diameter becomes smaller than the radius of the smallest bulb. The role of emulsifiers is also discussed. (Less)
Abstract (Swedish)
Turbulent breakup in emulsification devices is a dynamic process. Small viscous drops undergo a sequence of oscillations before entering the monotonic deformation phase leading to breakup. The turbulence-interface interactions prior to reaching critical deformation are therefore essential for understanding and modeling breakup. This contribution uses numerical experiments to characterize the critically deformed state (defined as a state from which breakup will follow deterministically, even if no further external stresses would act on the drop). Critical deformation does not coincide with a threshold maximum surface area, as previously suggested. A drop is critically deformed when a neck has formed locally with a curvature such that the... (More)
Turbulent breakup in emulsification devices is a dynamic process. Small viscous drops undergo a sequence of oscillations before entering the monotonic deformation phase leading to breakup. The turbulence-interface interactions prior to reaching critical deformation are therefore essential for understanding and modeling breakup. This contribution uses numerical experiments to characterize the critically deformed state (defined as a state from which breakup will follow deterministically, even if no further external stresses would act on the drop). Critical deformation does not coincide with a threshold maximum surface area, as previously suggested. A drop is critically deformed when a neck has formed locally with a curvature such that the Laplace pressure exceeds that of the smallest of the bulbs connected by the neck. This corresponds to a destabilizing internal flow, further thinning the neck. Assuming that the deformation leads to two spherical bulbs linked by a cylindrical neck, the critical deformation is achieved when the neck diameter becomes smaller than the radius of the smallest bulb. The role of emulsifiers is also discussed.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Emulsification, Drop breakup, DNS, Turbulence, Deformation, Emulsion
in
Colloids and Surfaces A: Physicochemical and Engineering Aspects
volume
648
article number
129213
pages
13 pages
publisher
Elsevier
external identifiers
  • scopus:85130907691
ISSN
0927-7757
DOI
10.1016/j.colsurfa.2022.129213
language
English
LU publication?
yes
id
675147a8-c81e-4025-8057-92d83359b9ee
date added to LUP
2022-06-01 07:45:18
date last changed
2023-12-19 23:23:56
@article{675147a8-c81e-4025-8057-92d83359b9ee,
  abstract     = {{Turbulent breakup in emulsification devices is a dynamic process. Small viscous drops undergo a sequence of oscillations before entering the monotonic deformation phase leading to breakup. The turbulence-interface interactions prior to reaching critical deformation are therefore essential for understanding and modeling breakup. This contribution uses numerical experiments to characterize the critically deformed state (defined as a state from which breakup will follow deterministically, even if no further external stresses would act on the drop). Critical deformation does not coincide with a threshold maximum surface area, as previously suggested. A drop is critically deformed when a neck has formed locally with a curvature such that the Laplace pressure exceeds that of the smallest of the bulbs connected by the neck. This corresponds to a destabilizing internal flow, further thinning the neck. Assuming that the deformation leads to two spherical bulbs linked by a cylindrical neck, the critical deformation is achieved when the neck diameter becomes smaller than the radius of the smallest bulb. The role of emulsifiers is also discussed.}},
  author       = {{Håkansson, Andreas and Crialesi-Esposito, Marco and Nilsson, Lars and Brandt, Luca}},
  issn         = {{0927-7757}},
  keywords     = {{Emulsification; Drop breakup; DNS; Turbulence; Deformation; Emulsion}},
  language     = {{eng}},
  month        = {{05}},
  publisher    = {{Elsevier}},
  series       = {{Colloids and Surfaces A: Physicochemical and Engineering Aspects}},
  title        = {{A criterion for when an emulsion drop undergoing turbulent deformation has reached a critically deformed state}},
  url          = {{http://dx.doi.org/10.1016/j.colsurfa.2022.129213}},
  doi          = {{10.1016/j.colsurfa.2022.129213}},
  volume       = {{648}},
  year         = {{2022}},
}