We present experimental observations of capillary ripples at the contact line of a droplet, spreading on a pre-wetted surface.
We use Digital Holographic Microscopy to measure the micro-scale undulation of the thin film. By raising the capillary number, the amplitude of the undulations increases at first and subsequently decreases.
At critical values of the capillary number, the ripples disappear. Using linear stability analysis, we further provide theoretical counterparts for the experimental observations, explaining the non-monotonic dependency on the capillary number
Place: PJ Lecture Hall
Time: 9 October, 2018, 11:00