Variable-geometry exit nozzle for improving static thrust of drones ducted fans

Unmanned aerial vehicles, or drones, are a technology that has seen rapid growth. Their ability to offload tasks that are once considered labor intensive is one of their many appealing aspects. This aspect increases time for tasks of higher importance, meaning reliance on this technology is ever increasing. These tasks include land geo-mapping, firefighting, surveillance, delivery services, search and rescue among others. As with every growing technology, however, comes the negative exposure, shadowing further expansion and growth. For drones, this includes noise pollution, and hazardous, low efficiency propulsion systems. Regulations and laws are beginning to surface, regulating the use of drones and their noise levels within airspace, as future growth can overcrowd airspace. Current drones use propulsion systems that expose the public to hazardous propellers and high levels of noise, thus unsuitable for their expected growth. This paper presents a novel variable-geometry exit nozzle to improve the efficiency of current propulsion systems in drones, in turn reducing noise levels and hazards, that are currently foreshadowing drones. The presented propulsion method achieves results that show better performance than a ducted fan and propeller under static conditions. Three experiments are conducted, and the results are reported and discussed.