Numerical modelling of droplet formation in a micro cross-junction

In this paper, liquid-liquid droplet formation in a cross-junction between stadium-shaped cross-section micro-channels has been studied by means of a CFD OpenFOAM approach. The particularity of the micro-junction considered in this paper is that within the junction the micro-channels have a restriction in the cross-section, while the shape remains stadium-shaped. The junction has the function to focus the dispersed flow and the droplets formed in certain regimes have dimensions that can be related to the dimensions of the junction. The object of this study is to characterise the dimensions of the droplets formed in this micro-junction. The evolution of the droplets are obtained for several ratios of the volume flow rates of the two fluids. A correlation between the dimensionless length of the droplet and the ratio of the volume flow rates are obtained and compared with other correlations available in the literature for different junctions.