Abstract
Offshore wind energy has experienced significant growth as a thriving industry, owing to the abundance of wind resources available in the open ocean. However, unlike their onshore counterparts, offshore wind turbines face greater exposure to environmental hazards, particularly ocean sprays. These sprays pose three primary hazards to offshore wind turbines: erosion, corrosion, and icing, due to saline droplets impacting and interacting with turbine surfaces. The primary goal of this research is to develop an innovative droplet-absorption-based surface technology capable of mitigating the hazards posed by ocean sprays. In this paper, a comprehensive experimental study was conducted to characterize the dynamic behaviors of droplets interacting with various porous geometries with modulated porosity and pore sizes. A high-speed imaging system was used to observe and experimentally analyze the impinging and penetration dynamics of the droplets as well as the competing inertial and capillary effects as droplets travel through porous geometries. It was found that the droplets impacting on the porous surfaces display various dynamics, depending on the relative scales of the droplet size and the pore size. The pore geometries, e.g., shape, spacing, and arrangement, also contribute to the discrepancies in droplet impact and penetration dynamics. A porous surface with gradient pores is also developed, which shows great potential in promoting droplet penetration through the surface. The findings in this paper pave the way for the incorporation of droplet-absorption-based surface technologies on wind turbine blades, making offshore wind farms more resilient and productive in the pursuit of renewable energy sustainability.
