Advancing drops on curved and flat surfaces.

The paper is concerned with the dynamics of advancing liquid blobs of fluid on curved and flat solid surfaces, such as cycloids and inclined planes. We investigate the kinematics of such blobs on hydrophobic surfaces with emphasis on the shape of the interface as the fluid advances. A theoretical model is proposed that captures the shape of the interface at early times. Also, the trajectory of the fluid, as it detaches from the cycloid, is investigated and compared with theoretical predictions. We find a good qualitative agreement between predictions and experimental data. As an extension of the present findings, we also investigate the shape and the dynamics of advancing drops on cycloids, placed in a viscous outer immiscible liquid. We find both similarities, in terms of kinematics, and specific differences in the shape of the advancing drop. [ABSTRACT FROM AUTHOR]