According to the world water council, more than 1 billion people do not have access to safe drinking water across the world (World Health Organization 2). The problem of lack of water is bigger in arid and semi aid areas where there is little to no rain; moreover, such areas tend to experience higher water transportation costs. A possible solution to the problem of water shortage in such areas would be to initiate fog harvesting (Damak 1). Fog comprises of tiny droplets with a diameter of about 10 μm. While researchers have come up with various artificial systems for harvesting fog, Damak (1) asserts that the most common system consists of a mesh that stands peculiar to the foggy wind. This project seeks to design a Fog harps for mounting on an aerostat. The project has two phases: One a proposed design for an aerostat for mounting the fog harps and secondly a proposed design for the fog harps. Fathieh et al. argue that there is some 13 sextillion (1021) litres of water are suspended in the atmosphere. Yet, this resource can be recycled to supply water in dry areas such as arid and semi-arid regions.
An effective mechanism of collecting water comprises of trapping the microscopic water droplets (fog) suspended in the wind. Harvesting of fog is possible and has been practised for many years across the world in areas such as the Middle East; South America and Africa. Fog harvesting has been considered a potential solution to the problem of water scarcity in dry areas (Shi et al. 11979). Fog nets are capable of producing clean water in the regions that experience moving fog. As wind moves the fog, water droplets get caught in the suspended wire and merge until they are heavy enough to move down the net and collect in a jar below. Some large fog harvesting projects have collected up to 6000 litres of water every day (Science daily, 2018). Traditionally, fog harvesters are designed in ways that have constrained the harvesting process. If the holes between the nets are too large, the wires fail to collect enough water; if the nets are fine, more water is collected causing clogging which then affects the ability of the droplets to run down to the collecting jar.
Additionally, clogging prevents wind from moving through the mesh. This project seeks to design a fog harvester that meets the trade-off – that is, one where the mesh is not too small and not too big. An iterative process of arriving at the geometric dimensions of the harvester is at this moment followed to ensure a more efficient design. This project, therefore, proposes the removal of the horizontal wires in the net to prevent clogging and enhance droplet movement. The harvester is to be attached to a tethered aerostat suspended 100 m above the ground for optimum fog collection.