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Shedding from chemically-treated oil droplets rising in seawater

Shedding from chemically-treated oil droplets rising in seawater

Category
Journal publication
Abstract
The degree to which droplet shedding (tip-streaming) can modify the size of rising oil droplets has been a topic of growing interest in relation to subsea dispersant injection. We present an experimental and numerical approach predicting oil droplet shedding, covering a wide range of viscosities and interfacial tensions. Shedding was observed within a specific range of droplet sizes when the oil viscosity is sufficiently high and the IFT is sufficiently low. The affected droplets are observed to reduce in size, as smaller satellite droplets are shed, until the parent droplet reaches a stable size. Shedding of smaller droplets is related to the viscosity-dominated modified capillary number (Ca′), especially for low dispersant dosages recommended for subsea dispersant injection. This, in combination with the IFT-dominated Weber number (We), characterise droplets into three possible states: 1) stable (Ca′ < 0.21 & We<12); 2) tip-streaming (Ca′ > 0.21 & We<12); 3) unstable and subject to total breakup (We>12).
Language
English
Author(s)
Affiliation
  • SINTEF Ocean / Miljø og nye ressurser
  • University of Hawai‘i at Mānoa
Year
2019
Published in
Marine Pollution Bulletin
ISSN
0025-326X
Volume
143
Page(s)
256 - 263