Droplet Dynamics in Constricted Microfluidic Channels

In the present work, we investigate the interfacial dynamics of a three dimensional droplet in a viscous fluid flowing through a microfluidic channel with a rectangular cross-sectional constriction. This problem is encountered in a broad range of applications in microfluidic devices and enhance oil recovery. The numerical computation of this system requires a highly-accurate and efficient method owing to the very small or large deformation of the droplet shape at low or high flow rates, the small droplet-solid gap and the complicated three-dimensional geometries. To facilitate this study, we utilize our efficient Fully-Implicit Spectral Boundary Element algorithm.

In this talk we will present our results for square and rectangular microchannels for a wide range of flow rates, viscosity ratios, droplet and constriction sizes. Our work shows that droplet dynamics is significantly influenced by the non-symmetric shape of the rectangular cross-sectional constriction with qualitatively different behavior at small and high flow rates as well as for small droplet-solid gaps.