Roy, Mme Emmy (2024) Influence of surfactants on bubbles break-up in a turbulent flow PRE - Research Project, ?? - ??.
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Abstract
When injected into a turbulent flow, bubbles undergo breakup, leading to size distribu- tions, N(d) with d the diameter of the bubble, that depend on the initial bubble size d0. Previous studies have shown that for cavities initially larger than the Hinze scale, the scale at which the surface tension is expected to prevent turbulent break-up, the distri- butions follow N(d) ∝ d−3/2 for bubbles smaller than the Hinze scale, and N(d) ∝ d−10/3 for bubbles larger than the Hinze scale. This study follows the work of Daniel Ruth’s PhD (2022). We focused on characterizing the impact of surfactants concentration on the breakup of an initial cavity of a given size. Our experimental setup was designed to replicate turbulence conditions similar to those found under a breaking wave. We employed two optical setups to achieve reliable visual- ization across a broad range of bubble sizes, and processed the images using Python. Our findings indicate that surfactants significantly influence the production of smaller bubbles. Specifically, as surfactant concentration increases, the number of sub-Hinze bubbles also increases, with this effect becoming more pronounced as the bubbles become smaller. Although the expected slopes of d−3/2 and d−10/3 did not clearly appear in our curves, we observed a change in slope around the Hinze scale. These results suggest that additives such as surfactants and salt in ocean water can affect bubble size distributions, thereby influencing ocean-atmosphere interactions.
Item Type: | Thesis (PRE - Research Project) |
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Uncontrolled Keywords: | Bubbles break-up, turbulence, surfactants, bubbles size distribution |
Subjects: | Chemistry, Physical Chemistry and Chemical Engineering Fluid Mechanics and Energy |
ID Code: | 10270 |
Deposited By: | Emmy ROY |
Deposited On: | 09 sept. 2024 13:51 |
Dernière modification: | 09 sept. 2024 13:51 |
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