Effect of uniform electric field on the deformation of a 2D liquid droplet in confined simple shear flow

TL;DR

This study investigates how a uniform electric field influences the deformation of a 2D liquid droplet in confined shear flow, revealing complex behaviors depending on dielectric properties and electric field strength, with implications for microfluidic device design.

Contribution

The paper provides a detailed numerical analysis of droplet deformation under electric fields in confined shear flow, considering both perfect and leaky dielectric models, highlighting the effects of confinement and electric parameters.

Findings

Deformation varies monotonically or non-monotonically with confinement based on dielectric properties.

Electric field strength significantly alters transient deformation dynamics.

Confinement enhances droplet deformation, potentially leading to breakup.

Abstract

In the present study, we have studied the electro-hydrodynamic of a physical system where a Newtonian dielectric liquid column or droplet suspended in another Newtonian dielectric liquid medium in presence of a simple shear flow. Taking both the phases as leaky dielectric and perfect dielectric in to consideration, we have performed 2D numerical solution for capturing the essential features of droplet deformation in between the parallel plate configuration. For a perfect dielectric system, this study shows that the deformation characteristic follows a monotonic as well as non-monotonic variation with domain confinement depending on the values of electrical permittivity ratio of the droplet and the surrounding fluid. For a leaky-dielectric system, presence of small conductivity further alters the deformation characteristic and it is happened that, at low electric field strength, the deformation increases with confinement monotonically. On contrary, deformation parameter shows non-monotonic variation with the domain confinement at higher electric field strength. Furthermore, in confined domain, the transient evolution of the deformation parameter is also markedly altered by the electric field strength in terms of steady state value of the deformation parameter and steady state time. Finally, the present analysis shows that the domain confinement significantly augment the deformation parameter in presence of electric field that leads to possible droplet break up phenomenon. From the present study, it is worthy to mention that domain confinement can be used to modulate the droplet morphology that has potential applications in modern-days droplet-based micro-fluidic devices.