Passage of a Taylor Bubble through a Stratified Liquid–Liquid Interface

Abstract

The bypass of an air bubble through a liquid−liquid interface may produce rich fluidic physics. Air injection is a passive technique to mix the contents of the two separated fluids and provides an effective heat and mass transfer intensification by increasing the interfacial area between them. Entrainment of heavier fluid into the lighter fluid at atmospheric and isothermal conditions has been simulated by using the VOF (volume of fluid) technique mimicking a Taylor bubble bypass through a horizontal liquid−liquid interface of water and polydimethylsiloxane (PDMS) solution. The migration of a Taylor bubble across the interface is completed through five different stages, namely, approach, encapsulation, de-encapsulation, entrainment, and detrainment. The bubble kinematics, entrained water volume, microdroplets formation, and film thinning characteristics have been studied in detail. The marginal pinch-off mechanism for the rupturing of the entrapped water film has been observed due to the presence of the surface tension gradient. The film thinning initially occurs due to the domination of gravitational force and eventually due to capillary force after the entrapped film thickness achieves capillary length scale, δ crit ∼ (σ/(ρg)) 1/2 . The entrapped water film shrinks over the interface of the Taylor bubble to generate the water microdroplets in the PDMS solution. The entrained height and volume of the water column grows quadratically with time.

Influence of the Immersion Ratio of a Revolving Roller on the Film Coating and Entrainment Dynamics

“…Dynamics of liquid coatings and entrainment is widely seen in both natural − and many industrial operations. − Specifically, the phenomenon of film flow and entrainment dynamics caused by the external rotational flux using a revolving drum(s) across the gas–liquid interface has remained challenging and popular among researchers − because there is a considerable improvement in exchange of mass, momentum, and energy with the expansion of interfacial area. It is needless to mention here that these investigations reveal the fundamental content of fluid dynamics as well as applicability for several industrially important processes.…”

Dynamics of a Rising Taylor Drop in a Stagnant Shear-Thinning Liquid

“…Gas–liquid slug flow is studied and well reported in the literature. ,− Liquid–liquid slug flow has gained interest in recent years due to its potential applications in chemical industries, oil well extraction, nuclear industries, and hydrocarbon transportation. , Despite having a wide range of industrial applications, there is a lack of literature concerning liquid–liquid slug flow. To have a deeper understanding of liquid–liquid slug flow, the primary step is to study the flow dynamics of a single Taylor drop rising in a stagnant or flowing continuous phase.…”

I&EC Research Special Issue on Fluidic Devices without Moving Parts

“…Some applications not envisaged at the time of the call are also seen (for example, a cook stove as a fluidic device without any moving parts). The contributions in this special issue may be broadly classified into four groups: Microfluidics/microreactors − Coils, curved channels, and inserts − Specialized fluidic devices − Other − …”