Recent years have seen rapid growth in the small-unmanned air vehicles (UAV) industry. This increase in drone usage causes many disruptions in our everyday lives, particularly noise. Increased noise regulations around residential and commercial areas, and the importance of a silent flight in military settings, mean that the acoustic signature of drones is of great concern. The use of electric propulsion systems has turned the propellers into a prominent source of noise. The quietness and the efficiency of propulsive system are key aspects in the design of UAV. Therefore, the ability to understand, predict and decrease rotor noise has become a major goal for both civil and military applications.
Within the scope the study, acoustic signature and aerodynamics performance of off-the-shelf APC Electric and in-house designed and manufactured (3D printed) propellers was studied in an anechoic environment. The aim of the study was not only understand the link between aeroacoustic and aerodynamic performance, but also suggest techniques to attenuate the acoustic signature. Treatments included the addition of surface roughness, applied a short distance downstream of the propeller’s leading edge, and application of trailing-edge serrations.
