2021/09/19 by Habib Abubakar, Omar K. Matar, Abubakar, Habib +1 · 1 citation
Engineering · #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics and Heat Transfer #Fluid Dynamics and Mixing #Particle Dynamics in Fluid Flows
paper · pdf · doi:10.48550/arxiv.2109.09096
openalex publication_date 2021/09/19 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
In this study, we examine the linear stability of an axisymmetric Taylor\nbubble moving steadily in a flowing liquid enclosed in a circular tube.\nLinearisation is performed about axisymmetric base states obtained in Part I of\nthis study by Abubakar and Matar (2021). The stability is characterised by the\ndimensionless inverse viscosity \( Nf \), E "otv "os \( Eo\n\), and Froude numbers \( Um \), the latter being based on\nthe centreline liquid velocity. The analysis shows that there exist regions of\n(Nf,Eo,Um) space within which the bubble is unstable and assumes an\nasymmetric shape. To elucidate the mechanisms underlying the instability, an\nenergy budget analysis is carried out which reveals that perturbation growth is\ndriven by the bubble pressure for Eo \≥ 100, and by the tangential\ninterfacial stress for Eo < 100. Examples of the asymmetric bubble shapes and\ntheir associated flow fields are also provided near the onset of instability\nfor a wide range of Nf, Eo, and Um.\n