Effect of Wettability on Fog Collection on a Cylindrical Wire*

Fog collection is a promising and sustainable solution to the global water scarcity problem, and is of great importance to industries including recapturing water in cooling towers of thermal power plants. In the past few decades, great progress on understanding the coupled effects of various fog collection system parameters has been made. However, how surface wettability of a single cylindrical wire affects detailed steps of fog collection and its performance remains unclear. Here, we conduct experiments using individual wires – the primarily components of conventional fog-collection systems. Experimental results show that the projected surface area of wires in the air flow direction during the fog collection process is affected by surface characteristics, namely wire diameter and wettability, and wind speed, which then significantly influence the fog collection rate of wires. The interesting observed droplet growth and transport phenomena on the wires are modeled by computer simulation. As such, our results and analyses provide an explanation for how surface characteristics influence fog collection, through experiments and simulations, and suggest how they can be utilized to create advanced fog-collection techniques, thus benefitting the fight against the global water crisis.