The Effect of Junction Gutters for the Upscaling of Droplet Generation in a Microfluidic T-Junction

TL;DR

This study numerically investigates how junction gutters in a microfluidic T-junction influence droplet formation, revealing configurations that enhance upscaling and identifying conditions where gutters are detrimental.

Contribution

It introduces gutter configurations in a T-junction and analyzes their effects on droplet formation, providing insights for improved microfluidic droplet generation.

Findings

JGs can increase formation frequency and alter droplet morphology.

Flow maps show transitions between dripping and jetting regimes.

Certain gutter designs are unfavorable for monodisperse droplets.

Abstract

The influence of drop formation due to micro rib-like structures, viz., the Junction Gutters (JGs) within a standard microfluidic T-junction, is numerically investigated. Hydrodynamic conditions that lead to various flow regimes are identified characterized by the Capillary number (Ca) and velocity ratios of the dispersed and continuous phases (q) within a standard T-junction. Subsequently, under such conditions, a range of gutter configurations is introduced in the standard channel. The results predict that the introduction of JGs can favourably alter the formation frequency and morphology of drops and, consequently, promote upscaling significantly for the hydrodynamic conditions associated with low Ca. Detailed flow maps are presented that reveal a plethora of transitions during the formation of droplets with higher Ca and q that would otherwise signify a dripping or a jetting regime in a standard junction. However, specific gutter configurations are identified where JGs are unfavourable for generating monodisperse droplets.