Final Report Summary - PHYSBOIL (Physics of liquid-vapor phase transition) We studied boiling process both on the micro- and macroscale. On the macroscale we focused on the enhanced heat transfer by boiling, numerically modeling this process and preparing measurements in turbulent boiling flow. On the microscale we tried to understand the nucleation of boiling, for which surface nanobubbles can be relevant. We also studied the impact of droplets on superheated surfaces, focusing on the heat transfer and on the spreading of the droplet. This has various applications for spray cooling in e.g. the electronic industry. We could also show that at drop impact a gas/vapor bubble is entrained and studied under what conditions this bubble is maximal. And unexpected application arose when we found that a laser pulse focused into a liquid-filled capillary can instantaneously produce a vapour bubble, which emits a shock wave, which then creates a thin, ultra-fast micro-jet (i.e. supersonic, up to 1000m/s). The jets can be 10 times smaller than the diameter of the micro-capillary. It is so fast that it shoots through skin, showing the potential of this method for needle-free injection.Note for the ERC staff: I would not mind at all to make my whole summary of the project public, rather than only this short section.
