Fog billboard + calculations

grabcad

The main goal during the development of Fog Billboard (FB) was to ensure its reliable and effective functioning under any weather conditions without requiring specialists for adjustments or repairs. The FB is highly efficient and cost-effective, utilizing a 1m³ space and weighing only 177kg. It features a small fog collector (2x2x2m), a metal net (21.3m²) outside the collector, and can withstand direct winds up to 70mph with a maximum tension of 6MN/sq.m and 0.7mm shifting. The height can be adjusted between 1.5m-3m over land level using a remade Hi-Lift system. To achieve optimal performance, the FB combines advantages from cylindrical and cubic net stretching methods. Testing various net structures, it was found that the cylindrical structure provided better streamlining while the cubic structure had a larger net area (4m²). The resulting Fog Billboard design directs the main fog stream to the corners during direct wind, and captures 90% of the fog in angular wind conditions for maximum contact with the net. The frame is constructed using lightweight aluminum shapes (40x4mm) with a material similar to steel but three times lighter. Frame strength calculations considered a net effective cross-section coefficient k=0.25 and additional equipment weight. The frame is secured by screwing into the land and fastening the design base with nuts, with angular points fixed using cables. The net weighs approximately 30kg and features flexible polymeric fringes with sealed metal holes for fixing. It is tensioned using springs at the top and hooks at the bottom to minimize water loss. The fog collection system consists of polymeric tubes guiding water from four angular points to a drain hose, which can be connected to a tank-collector or directly to a house. Four pre-filters are used to prevent foliage and dirt from entering the hoses.