2023-05-03 ブラウン大学
◆物理学の新しい研究によると、シャンパンが泡を縦一列に上げるのは、界面活性剤と呼ばれる洗剤様の化合物の存在によるものだという。これにより、泡がスムーズに上がるようになり、安定した泡列を作ることができる。
◆この調査により、泡のクラスター形成における流体力学に関する重要な洞察を得たとのこと。
＜関連情報＞
- https://www.brown.edu/news/2023-05-03/champagne-bubbles
- https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.8.053601
界面活性剤の存在が炭酸飲料中の気泡鎖の安定性を制御する Presence of surfactants controls the stability of bubble chains in carbonated drinks
Omer Atasi, Mithun Ravisankar, Dominique Legendre and Roberto Zenit
Physical Review Fluids Published: 3 May 2023
DOI:https://doi.org/10.1103/PhysRevFluids.8.053601
ABSTRACT
Bubbles appear when a carbonated drink is poured in a glass. Very stable bubble chains are clearly observed in champagne, showing an almost straight line from microscopic nucleation sites from which they are continuously formed. In some other drinks such as soda, such chains are not straight (not stable). Considering pair interactions for spherical clean bubbles, bubble chains should not be stable, which contradicts these observations. The aim of this work is to explain the conditions for bubble chain stability. For this purpose, experiments and direct numerical simulation are conducted. The bubble size as well as the level of interface contamination are varied to match the range of parameters in typical drinks. Both factors are shown to affect the bubble chain stability. The transition from stable to unstable behavior results from the reversal of the lift force, which is induced by the bubble wake. A criteria based on the production of vorticity at the bubble surface is proposed to identify the conditions of transition from stable to unstable bubble chains. Beyond carbonated drinks, understanding bubble clustering has impact in many two-phase problems of current importance.
