Instability of a swirling bubble ring

• Published in: Comptes Rendus. Mécanique
• Main Authors: Xu, Yonghui, Delbende, Ivan, Fuster, Daniel, Rossi, Maurice
• Other Authors: Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur (LIMSI), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), DAta science, TrAnsition, Fluid instabiLity, contrOl, Turbulence (DATAFLOT), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Fluides Réactifs et Turbulence (IJLRDA-FRT), Institut Jean Le Rond d'Alembert (DALEMBERT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Instability; Vortex ring; Two-phase flow; Direct numerical simulation; [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph]; Beluga; Beluga*
• Online Access: https://hal.science/hal-02993273; https://hal.science/hal-02993273/document; https://hal.science/hal-02993273/file/crmeca20200971-1.pdf; https://doi.org/10.5802/crmeca.22

International audience A toroidal bubble or a cylindrical gas jet are known to be subjected to the Rayleigh-Plateau instability. Air bubble rings produced by beluga whales and dolphins however are observed that remain stable for long times. In the present work, we analyse the generation of such toroidal bubbles via numerical simulations , in particular how the process depends on surface tension. Their stability properties are then briefly analysed. For the estimated Reynolds and Weber numbers relative to the bubbles produced by these animals, the presence of a vortex inside and around the bubble is found to strongly stabilize the Rayleigh-Plateau instability .