On Transformation of a Taylor Bubble to an Asymmetric Sectorial Wrap in an Annuli

Abstract

Genesis of an asymmetric sectorial wrap of air from a Taylor bubble upon facing concentric annular obstruction in a stagnant kerosene column is investigated. Careful observations are reported from processed images taken using high speed camera and with finite volume based simulations. The interfacial reconstruction of a Taylor bubble is completed through six distinct stages, namely, plateau formation, doughnut shape bypass of obstruction followed by nucleation, preferential rise, retraction of the lagging lobe and subsequent thread formation, consumption of thread including bubble segment stage, and finally the manifestation of the annular bubble before rising as steady annular sectorial wrap. Analysis of experimental observations related to interfacial rise and kinematic estimation from numerical study is presented in support of claims related to different transformation stages. A close similarity has also been reported between the stages involved in the interfacial reconstruction process and classical Rayleigh–Taylor instability.

Understanding of Fluidic Physics during Bypass of a Taylor Bubble around a Transverse Insert in a Viscous Medium

“…The equal growth of these two protrusions can be noticed for some time (0.124 s; constrained by the surface tension) before causing a preferential rise of one lobe and consumption of the other (stage 3). Nonlinear stages of Rayleigh–Taylor instability (RTI) trigger a competition between the growing lobes and eventually lead to the preference of one randomly over the other. − , Retarding the lobe makes way for drainage of the liquid and facilitates the bypass of air from another side. The leading lobe, on the other hand, grows above the cylinder and envelopes it (stage 4b).…”

Development of closure relations for the motion of Taylor bubbles in vertical and inclined annular pipes using high-fidelity numerical modeling

“…6 In recent years, a number of investigations have sought to provide insight into these bubbles in tubular pipes, 5,[7][8][9][10] but the understanding of their behavior in annular conduits is still limited. 11,12 The importance of this piping configuration has increased, for example, with the unconventional extraction techniques used to maintain supply of natural gas among the depletion of conventional reservoirs. 13 Determining the pressure gradient through conduits in the presence of multiphase flow is often addressed using empirical and/or mechanistic models.…”

“…The aforementioned studies were all focused on Taylor bubbles in conduits without internal obstructions (e.g., the internal pipe in an annular conduit). In comparison, a computational solution for Taylor bubbles in annular pipes has only recently been published in the work of Rohilla and Das 11 and Mitchell et al [26][27][28] These groups used the coupled level set-volume of fluid (CLSVOF) and phasefield lattice Boltzmann method (PF-LBM), respectively, to capture the interfacial evolution. Rohilla and Das additionally performed experiments to validate their simulations but focused on the transition of the Taylor bubble moving from a tubular to annular region.…”

Analysis of Taylor bubble dynamics via high-fidelity numerical modelling

“…It is only very recent that computational multi-fluid dynamics has been applied to study Taylor bubbles in annular conduits [4,12,13]. Rohilla and Das [12] coupled a level set-volume of fluid approach to capture the interface evolution, focusing on the dynamics as a bubble progressed from a tubular pipe into an annular conduit.…”

“…It is only very recent that computational multi-fluid dynamics has been applied to study Taylor bubbles in annular conduits [4,12,13]. Rohilla and Das [12] coupled a level set-volume of fluid approach to capture the interface evolution, focusing on the dynamics as a bubble progressed from a tubular pipe into an annular conduit. Mitchell and Leonardi [4,13] provide the basis for this paper, and applied a coupled phase-field lattice Boltzmann approach to characterise the behaviour of Taylor bubbles in various fluids and flow conditions.…”