A. Schwarzwälder, F. Freese, J. Meyer, K, Loganathan, H. Tietze, A. Dittler, U. Janoske

Physics of Fluids 2024, 36, 032006, https://doi.org/10.1063/5.0188784

In this study, for the first time, the droplet–fiber interaction on a mechanically excited fiber is examined in the direction of the fiber axis. Highly spatially and temporally resolved simulations and experimental investigations provide information on the relative position of the center of the projected area of the droplet and the center of the fiber, the relative angular position, and the deformation of the droplet using a skeleton line. To attain this, a state-of-the-art camera technology was employed in the experiments, while the volume of fluid method was utilized for the modeling of the multi-phase flow. Additionally, an overset method for the movement of the fiber was applied in the computational fluid dynamics simulations. Characteristic motion patterns, whether occurring in isolation, in sequence, or superimposed, are identified, representing a prerequisite for the detachment of the droplet from the fiber. Despite the simplified assumption of a two-dimensional simulation, the motion patterns observed in the simulation are in good agreement with the experimental data. The obtained results contribute to a fundamental understanding of the mechanisms responsible for the detachment of a droplet in the context of the droplet–fiber interaction within the excited coalescence filters.