Within this thesis, we are focusing on the development of superhydrophobic surfaces with laser-fabricated pillars to prevent the freezing of water droplets impacting the surface. The freezing of droplets that impact subcooled surfaces is a common problem in many areas, including aviation and maritime transport, power lines, heat pump evaporators, and windshields. To prevent droplet freezing, passive protection methods in the form of superhydrophobic surfaces that repel water droplets are being rapidly developed. For the fabrication of superhydrophobic surfaces on aluminum samples, we used laser processing with nanosecond laser pulses, while the surfaces were rendered hydrophobic by applying a thin low-surface-energy coating. We evaluated the droplet repellency capability and monitored droplet spreading on the surface at various surface temperatures and droplet velocities. We found that both the spacing between the laser-fabricated pillars and the pillar dimensions significantly influence the ability to repel water droplets, especially under unfavorable combinations of parameters, such as low surface temperatures and high droplet velocities.
|
