Some exploratory aspects of two-liquid flows in microgeometries

An experimental study concerning two-liquid channel flows and the corresponding flow regimes at the millimetric scale is presented for a wide range of the flow rate ratio. The injection of two pairs of miscible liquids leads to the development of wave-like instabilities and to the formation of droplet-like diffusive slugs, that we characterize by means of their oscillation and production frequency. We extend our research to the microscale by testing the droplet formation capabilities of a divergent-convergent microfluidic chamber. A method of deflecting satellite droplets from a layer of monodisperse droplets is observed when an obstacle is present in the microfluidic chamber.