When a liquid does not have the time or space to flow, it can (in the absence of weak spots) sustain a substantial tension while remaining in the liquid state. Tension can for example be applied to a liquid through (fast) pulling, superheating, supercooling, or supersaturating. On a high level the framework of thermodynamics unifies all these metastable situations. However, the detailed dynamics and phenomenology is different in each case. When a high tension is suddenly released, the liquid undergoes a rapid partial phase transition to a vapor/gas, a solid or a void (cavitation), giving the surrounding medium little time to respond. This leads to surprising and complex interactions, especially if also the surroundings were put under tension in the process. Such explosive chain reactions commonly occur in industrial and natural processes. A fundamental understanding is therefore often of great importance. However, the short time and length scales usually involved make it challenging to acquire this knowledge. In this thesis several cases were visualized and analyzed in detail for the first time, using a combination of (high speed) imaging techniques, numerical simulations and analytical modeling. It is about bubbles that can form when two solid materials are rubbed together in a supersaturated liquid (tribonucleation), about superheated droplets (Leidenfrost droplets) which start to jump when placed in a strong electric field, and about the spontaneous freezing and bursting of supercooled water droplets.
|Award date||4 Sep 2015|
|Place of Publication||Enschede|
|Publication status||Published - 4 Sep 2015|