Droplets occur in many areas of a vehicle. Condensation-induced droplet formation in exhaust systems can lead to thermal shock, corrosion, etc. in sensors and electronic components. Droplet-related contamination on components, such as camera systems, mirrors, etc., can result in functional impairments. The efficient separation and transport of oil and water droplets in filter systems should also be mentioned. For the design of these systems, knowledge of droplet motion behaviour is of crucial importance. In addition to the desired motion, for example during the removal of droplets from camera systems, droplets must be kept away from undesired deposition locations, such as electronic components and sensors. In all of the examples mentioned, droplets are subjected to aerodynamic forces as well as vibrational excitations induced by mechanical vibrations and flow-induced oscillations.

Within the scope of the presentation, the effects of these superimposed forces on droplet motion are investigated both numerically and experimentally. It is shown that, when both forces are superimposed, there is a significant difference in motion depending on the frequency range, which can potentially be exploited for the design of such systems. For the numerical modelling of droplet dynamics, grid-based finite volume methods using the Volume-of-Fluid (VoF) approach are employed, supplemented with models accounting for contact angle hysteresis. The various methods, as well as their experimental validation using diverse laser-optical techniques (LDA, PIV, 3D particle tracking, shadowgraphy), are presented for different geometries.