Controlled droplet motion—particularly its initiation—plays a central role in numerous applications in chemical and pharmaceutical engineering. While the behavior of droplets that wet a single surface has already been extensively studied, our understanding of droplets that simultaneously wet two opposing walls and extend beyond the configuration of a Hele-Shaw cell remains limited. In particular, there is a lack of systematic studies on the interaction of aerodynamic forces, gravity, and mechanical vibration excitation on the detachment and motion behavior of such droplets.

The goal of the project is the experimental and numerical analysis of the detachment and motion behavior of double-wetting droplets in gaps between plane-parallel plates. By systematically varying flow velocity, droplet properties, and wall materials, different motion regimes under the influence of gravity and vibration are identified and characterized. The experimental investigations include optical measurements using shadowing techniques and particle-image velocimetry to analyze droplet shape and flow fields. In parallel, numerical simulations are performed and validated in OpenFOAM using the volume-of-fluid method to describe the underlying physical mechanisms in detail.

By combining experiments and simulations, a fundamental understanding of the relevant influencing factors and mechanisms is developed. The insights gained enable the prediction of droplet behavior in comparable systems and contribute to the targeted control of droplet motion in technical applications.

The project is funded by the German Research Foundation (DFG).