| Autor: |
Herrada MA; Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Seville 41092, Spain., Eggers JG; School of Mathematics, University of Bristol, Bristol BS8 1UG, United Kingdom. |
| Jazyk: |
angličtina |
| Zdroj: |
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2023 Jan 24; Vol. 120 (4), pp. e2216830120. Date of Electronic Publication: 2023 Jan 17. |
| DOI: |
10.1073/pnas.2216830120 |
| Abstrakt: |
It has been documented since the Renaissance that an air bubble rising in water will deviate from its straight, steady path to perform a periodic zigzag or spiral motion once the bubble is above a critical size. Yet, unsteady bubble rise has resisted quantitative description, and the physical mechanism remains in dispute. Using a numerical mapping technique, we for the first time find quantitative agreement with high-precision measurements of the instability. Our linear stability analysis shows that the straight path of an air bubble in water becomes unstable to a periodic perturbation (a Hopf bifurcation) above a critical spherical radius of R = 0.926 mm, within 2% of the experimental value. While it was previously believed that the bubble's wake becomes unstable, we now demonstrate a new mechanism, based on the interplay between flow and bubble deformation. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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