Evaluation of the Effectiveness and Impact of Wetting the Surface of the Collector Mesh on the Process of Collecting Atmospheric Fog

Fog collectors can be an efficient source of fresh water in areas with constant air advection. A key feature of any collection device is the mesh used to capture the fog droplets. In this paper, we combine a fog collection experiment performed in natural field conditions for meshes with different degrees of wetting of the fibers with a theoretical analysis of the aerodynamics of air near the collector, carried out on the basis of computer simulation of the flow. The obtained overall collection efficiency of a collector grid with a shading coefficient s = 0.2 for the weather conditions of the Kerch Peninsula was η_coll = 0.045 for a hydrophilic and η_coll = 0.022 for a superhydrophobic surface. This phenomenon is confirmed by the analysis of the forces acting on the drop and the calculation of the drainage coefficient for two types of coatings. It has been shown that droplets with a volume of up to 1 μL will not fall into the collection trough, but will overcome the cohesion force and return back to the atmosphere. In general, the described technology is simple, economical and does not require energy consumption. Based on the experience of several countries, the effectiveness of a technology can be guaranteed if technical, social and managerial factors are taken into account in its planning and implementation.