Shear-induced displacement of droplets from a solid substrate
P. D. M. Spelt (Department of Chemical Engineering, Imperial College London, UK) and H. Ding (Department of Chemical Engineering, Imperial College London, UK)
Direct numerical simulations of shear flow past a droplet on a solid surface reveal various flow regimes. When the window of contact hysteresis is sufficiently small, droplets start to move, and can reach a quasi steady state. We report here on numerical results for a macroscale contact angle as a function of a capillary number. At large enough shear, part of the droplet is elongated and pinches off. Detailed quantitative results are presented on this process. At higher shear, multiple droplets are formed. We also investigate the corresponding critical conditions for entrainment, as well as for the onset of motion.