Finite droplets vs long droplets: Discrepancy in release conditions in a microscopic constricted channel

摘要: Conditions of release of trapped droplets in constricted channels are of great significance in various domains, including microfluidic development and enhanced oil recovery. In our previous studies, a detailed and quantitative analysis of the threshold pressure needed to release a droplet from a constricted channel has been performed. However, droplets may exist in real applications as long droplets, which may exhibit different behavior than finite droplets. Therefore, in this study, direct numerical simulations, combining the fluid flow equations and the phase-field method, have been conducted on three-dimensional constrained channels to investigate discrepancies in release conditions of finite droplets and long droplets. The results have shown that for a finite droplet, the maximum pressure increases with the increase in the contact angle, whereas for a long droplet, the maximum pressure is almost the same both in …