A CFD simulation tool for experimental prediction of inflow polymeric microdroplet formation in a T-junction configuration

A simulation tool to predict the morphological features and dynamics of polymeric microdroplets in a microfluidic T-junction is presented. A phase-diagram of regimes is created moving from dripping to squeezing within ranges of 10⁻²–10⁻⁴ and 10⁻¹–10⁻³ for Reynolds and Capillary numbers, respectively. The simulations show the strong influence of the continuous phase over the droplet size, which changes two orders of magnitude -increasing from 10¹ to 10² μm- as the flowrate becomes higher.

The phase-diagram allows to choose the optimal fluid-flow conditions to have a precise and stable dripping production of spherical drops. Indeed, a successful down-scaling of drop size up to ∼10¹ μm with a drop rate production of ∼40 drops/s is obtained, with a great accordance between simulative and experimental results (error < 1 %), at high monodispersity (polydispersity index<0.05). Therefore, our tool has proved to be a powerful approach to predict and regulate polymeric microdroplet production in microfluidics.